xref: /freebsd/sys/dev/iscsi/iscsi.c (revision 86c9d9918f1db7cdd968b60f8902466887bcd9e9)
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/socket.h>
47 #include <sys/sysctl.h>
48 #include <sys/systm.h>
49 #include <sys/sx.h>
50 #include <vm/uma.h>
51 
52 #include <cam/cam.h>
53 #include <cam/cam_ccb.h>
54 #include <cam/cam_xpt.h>
55 #include <cam/cam_debug.h>
56 #include <cam/cam_sim.h>
57 #include <cam/cam_xpt_sim.h>
58 #include <cam/cam_xpt_periph.h>
59 #include <cam/cam_periph.h>
60 #include <cam/scsi/scsi_all.h>
61 #include <cam/scsi/scsi_message.h>
62 
63 #include <dev/iscsi/icl.h>
64 #include <dev/iscsi/icl_wrappers.h>
65 #include <dev/iscsi/iscsi_ioctl.h>
66 #include <dev/iscsi/iscsi_proto.h>
67 #include <dev/iscsi/iscsi.h>
68 
69 #ifdef ICL_KERNEL_PROXY
70 #include <sys/socketvar.h>
71 #endif
72 
73 #ifdef ICL_KERNEL_PROXY
74 FEATURE(iscsi_kernel_proxy, "iSCSI initiator built with ICL_KERNEL_PROXY");
75 #endif
76 
77 /*
78  * XXX: This is global so the iscsi_unload() can access it.
79  * 	Think about how to do this properly.
80  */
81 static struct iscsi_softc	*sc;
82 
83 SYSCTL_NODE(_kern, OID_AUTO, iscsi, CTLFLAG_RD, 0, "iSCSI initiator");
84 static int debug = 1;
85 SYSCTL_INT(_kern_iscsi, OID_AUTO, debug, CTLFLAG_RWTUN,
86     &debug, 0, "Enable debug messages");
87 static int ping_timeout = 5;
88 SYSCTL_INT(_kern_iscsi, OID_AUTO, ping_timeout, CTLFLAG_RWTUN, &ping_timeout,
89     0, "Timeout for ping (NOP-Out) requests, in seconds");
90 static int iscsid_timeout = 60;
91 SYSCTL_INT(_kern_iscsi, OID_AUTO, iscsid_timeout, CTLFLAG_RWTUN, &iscsid_timeout,
92     0, "Time to wait for iscsid(8) to handle reconnection, in seconds");
93 static int login_timeout = 60;
94 SYSCTL_INT(_kern_iscsi, OID_AUTO, login_timeout, CTLFLAG_RWTUN, &login_timeout,
95     0, "Time to wait for iscsid(8) to finish Login Phase, in seconds");
96 static int maxtags = 255;
97 SYSCTL_INT(_kern_iscsi, OID_AUTO, maxtags, CTLFLAG_RWTUN, &maxtags,
98     0, "Max number of IO requests queued");
99 static int fail_on_disconnection = 0;
100 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_disconnection, CTLFLAG_RWTUN,
101     &fail_on_disconnection, 0, "Destroy CAM SIM on connection failure");
102 static int fail_on_shutdown = 1;
103 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_shutdown, CTLFLAG_RWTUN,
104     &fail_on_shutdown, 0, "Fail disconnected sessions on shutdown");
105 
106 static MALLOC_DEFINE(M_ISCSI, "iSCSI", "iSCSI initiator");
107 static uma_zone_t iscsi_outstanding_zone;
108 
109 #define	CONN_SESSION(X)	((struct iscsi_session *)X->ic_prv0)
110 #define	PDU_SESSION(X)	(CONN_SESSION(X->ip_conn))
111 
112 #define	ISCSI_DEBUG(X, ...)						\
113 	do {								\
114 		if (debug > 1) 						\
115 			printf("%s: " X "\n", __func__, ## __VA_ARGS__);\
116 	} while (0)
117 
118 #define	ISCSI_WARN(X, ...)						\
119 	do {								\
120 		if (debug > 0) {					\
121 			printf("WARNING: %s: " X "\n",			\
122 			    __func__, ## __VA_ARGS__);			\
123 		}							\
124 	} while (0)
125 
126 #define	ISCSI_SESSION_DEBUG(S, X, ...)					\
127 	do {								\
128 		if (debug > 1) {					\
129 			printf("%s: %s (%s): " X "\n",			\
130 			    __func__, S->is_conf.isc_target_addr,	\
131 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
132 		}							\
133 	} while (0)
134 
135 #define	ISCSI_SESSION_WARN(S, X, ...)					\
136 	do {								\
137 		if (debug > 0) {					\
138 			printf("WARNING: %s (%s): " X "\n",		\
139 			    S->is_conf.isc_target_addr,			\
140 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
141 		}							\
142 	} while (0)
143 
144 #define ISCSI_SESSION_LOCK(X)		mtx_lock(&X->is_lock)
145 #define ISCSI_SESSION_UNLOCK(X)		mtx_unlock(&X->is_lock)
146 #define ISCSI_SESSION_LOCK_ASSERT(X)	mtx_assert(&X->is_lock, MA_OWNED)
147 #define ISCSI_SESSION_LOCK_ASSERT_NOT(X) mtx_assert(&X->is_lock, MA_NOTOWNED)
148 
149 static int	iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg,
150 		    int mode, struct thread *td);
151 
152 static struct cdevsw iscsi_cdevsw = {
153      .d_version = D_VERSION,
154      .d_ioctl   = iscsi_ioctl,
155      .d_name    = "iscsi",
156 };
157 
158 static void	iscsi_pdu_queue_locked(struct icl_pdu *request);
159 static void	iscsi_pdu_queue(struct icl_pdu *request);
160 static void	iscsi_pdu_update_statsn(const struct icl_pdu *response);
161 static void	iscsi_pdu_handle_nop_in(struct icl_pdu *response);
162 static void	iscsi_pdu_handle_scsi_response(struct icl_pdu *response);
163 static void	iscsi_pdu_handle_task_response(struct icl_pdu *response);
164 static void	iscsi_pdu_handle_data_in(struct icl_pdu *response);
165 static void	iscsi_pdu_handle_logout_response(struct icl_pdu *response);
166 static void	iscsi_pdu_handle_r2t(struct icl_pdu *response);
167 static void	iscsi_pdu_handle_async_message(struct icl_pdu *response);
168 static void	iscsi_pdu_handle_reject(struct icl_pdu *response);
169 static void	iscsi_session_reconnect(struct iscsi_session *is);
170 static void	iscsi_session_terminate(struct iscsi_session *is);
171 static void	iscsi_action(struct cam_sim *sim, union ccb *ccb);
172 static void	iscsi_poll(struct cam_sim *sim);
173 static struct iscsi_outstanding	*iscsi_outstanding_find(struct iscsi_session *is,
174 		    uint32_t initiator_task_tag);
175 static struct iscsi_outstanding	*iscsi_outstanding_add(struct iscsi_session *is,
176 		    struct icl_pdu *request, union ccb *ccb,
177 		    uint32_t *initiator_task_tagp);
178 static void	iscsi_outstanding_remove(struct iscsi_session *is,
179 		    struct iscsi_outstanding *io);
180 
181 static bool
182 iscsi_pdu_prepare(struct icl_pdu *request)
183 {
184 	struct iscsi_session *is;
185 	struct iscsi_bhs_scsi_command *bhssc;
186 
187 	is = PDU_SESSION(request);
188 
189 	ISCSI_SESSION_LOCK_ASSERT(is);
190 
191 	/*
192 	 * We're only using fields common for all the request
193 	 * (initiator -> target) PDUs.
194 	 */
195 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
196 
197 	/*
198 	 * Data-Out PDU does not contain CmdSN.
199 	 */
200 	if (bhssc->bhssc_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_OUT) {
201 		if (ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn) &&
202 		    (bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0) {
203 			/*
204 			 * Current MaxCmdSN prevents us from sending any more
205 			 * SCSI Command PDUs to the target; postpone the PDU.
206 			 * It will get resent by either iscsi_pdu_queue(),
207 			 * or by maintenance thread.
208 			 */
209 #if 0
210 			ISCSI_SESSION_DEBUG(is, "postponing send, CmdSN %u, "
211 			    "ExpCmdSN %u, MaxCmdSN %u, opcode 0x%x",
212 			    is->is_cmdsn, is->is_expcmdsn, is->is_maxcmdsn,
213 			    bhssc->bhssc_opcode);
214 #endif
215 			return (true);
216 		}
217 		bhssc->bhssc_cmdsn = htonl(is->is_cmdsn);
218 		if ((bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0)
219 			is->is_cmdsn++;
220 	}
221 	bhssc->bhssc_expstatsn = htonl(is->is_statsn + 1);
222 
223 	return (false);
224 }
225 
226 static void
227 iscsi_session_send_postponed(struct iscsi_session *is)
228 {
229 	struct icl_pdu *request;
230 	bool postpone;
231 
232 	ISCSI_SESSION_LOCK_ASSERT(is);
233 
234 	while (!STAILQ_EMPTY(&is->is_postponed)) {
235 		request = STAILQ_FIRST(&is->is_postponed);
236 		postpone = iscsi_pdu_prepare(request);
237 		if (postpone)
238 			break;
239 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
240 		icl_pdu_queue(request);
241 	}
242 }
243 
244 static void
245 iscsi_pdu_queue_locked(struct icl_pdu *request)
246 {
247 	struct iscsi_session *is;
248 	bool postpone;
249 
250 	is = PDU_SESSION(request);
251 	ISCSI_SESSION_LOCK_ASSERT(is);
252 	iscsi_session_send_postponed(is);
253 	postpone = iscsi_pdu_prepare(request);
254 	if (postpone) {
255 		STAILQ_INSERT_TAIL(&is->is_postponed, request, ip_next);
256 		return;
257 	}
258 	icl_pdu_queue(request);
259 }
260 
261 static void
262 iscsi_pdu_queue(struct icl_pdu *request)
263 {
264 	struct iscsi_session *is;
265 
266 	is = PDU_SESSION(request);
267 	ISCSI_SESSION_LOCK(is);
268 	iscsi_pdu_queue_locked(request);
269 	ISCSI_SESSION_UNLOCK(is);
270 }
271 
272 static void
273 iscsi_session_logout(struct iscsi_session *is)
274 {
275 	struct icl_pdu *request;
276 	struct iscsi_bhs_logout_request *bhslr;
277 
278 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
279 	if (request == NULL)
280 		return;
281 
282 	bhslr = (struct iscsi_bhs_logout_request *)request->ip_bhs;
283 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST;
284 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
285 	iscsi_pdu_queue_locked(request);
286 }
287 
288 static void
289 iscsi_session_terminate_task(struct iscsi_session *is,
290     struct iscsi_outstanding *io, bool requeue)
291 {
292 
293 	ISCSI_SESSION_LOCK_ASSERT(is);
294 
295 	if (io->io_ccb != NULL) {
296 		io->io_ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
297 		if (requeue)
298 			io->io_ccb->ccb_h.status |= CAM_REQUEUE_REQ;
299 		else
300 			io->io_ccb->ccb_h.status |= CAM_REQ_ABORTED;
301 		if ((io->io_ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
302 			io->io_ccb->ccb_h.status |= CAM_DEV_QFRZN;
303 			xpt_freeze_devq(io->io_ccb->ccb_h.path, 1);
304 			ISCSI_SESSION_DEBUG(is, "freezing devq");
305 		}
306 		xpt_done(io->io_ccb);
307 	}
308 	iscsi_outstanding_remove(is, io);
309 }
310 
311 static void
312 iscsi_session_terminate_tasks(struct iscsi_session *is, bool requeue)
313 {
314 	struct iscsi_outstanding *io, *tmp;
315 
316 	ISCSI_SESSION_LOCK_ASSERT(is);
317 
318 	TAILQ_FOREACH_SAFE(io, &is->is_outstanding, io_next, tmp) {
319 		iscsi_session_terminate_task(is, io, requeue);
320 	}
321 }
322 
323 static void
324 iscsi_session_cleanup(struct iscsi_session *is, bool destroy_sim)
325 {
326 	struct icl_pdu *pdu;
327 
328 	ISCSI_SESSION_LOCK_ASSERT(is);
329 
330 	/*
331 	 * Don't queue any new PDUs.
332 	 */
333 	if (is->is_sim != NULL && is->is_simq_frozen == false) {
334 		ISCSI_SESSION_DEBUG(is, "freezing");
335 		xpt_freeze_simq(is->is_sim, 1);
336 		is->is_simq_frozen = true;
337 	}
338 
339 	/*
340 	 * Remove postponed PDUs.
341 	 */
342 	while (!STAILQ_EMPTY(&is->is_postponed)) {
343 		pdu = STAILQ_FIRST(&is->is_postponed);
344 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
345 		icl_pdu_free(pdu);
346 	}
347 
348 	if (destroy_sim == false) {
349 		/*
350 		 * Terminate SCSI tasks, asking CAM to requeue them.
351 		 */
352 		iscsi_session_terminate_tasks(is, true);
353 		return;
354 	}
355 
356 	iscsi_session_terminate_tasks(is, false);
357 
358 	if (is->is_sim == NULL)
359 		return;
360 
361 	ISCSI_SESSION_DEBUG(is, "deregistering SIM");
362 	xpt_async(AC_LOST_DEVICE, is->is_path, NULL);
363 
364 	if (is->is_simq_frozen) {
365 		xpt_release_simq(is->is_sim, 1);
366 		is->is_simq_frozen = false;
367 	}
368 
369 	xpt_free_path(is->is_path);
370 	is->is_path = NULL;
371 	xpt_bus_deregister(cam_sim_path(is->is_sim));
372 	cam_sim_free(is->is_sim, TRUE /*free_devq*/);
373 	is->is_sim = NULL;
374 	is->is_devq = NULL;
375 }
376 
377 static void
378 iscsi_maintenance_thread_reconnect(struct iscsi_session *is)
379 {
380 
381 	icl_conn_close(is->is_conn);
382 
383 	ISCSI_SESSION_LOCK(is);
384 
385 	is->is_connected = false;
386 	is->is_reconnecting = false;
387 	is->is_login_phase = false;
388 
389 #ifdef ICL_KERNEL_PROXY
390 	if (is->is_login_pdu != NULL) {
391 		icl_pdu_free(is->is_login_pdu);
392 		is->is_login_pdu = NULL;
393 	}
394 	cv_signal(&is->is_login_cv);
395 #endif
396 
397 	if (fail_on_disconnection) {
398 		ISCSI_SESSION_DEBUG(is, "connection failed, destroying devices");
399 		iscsi_session_cleanup(is, true);
400 	} else {
401 		iscsi_session_cleanup(is, false);
402 	}
403 
404 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
405 	    ("destroying session with active tasks"));
406 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
407 	    ("destroying session with postponed PDUs"));
408 
409 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
410 		ISCSI_SESSION_UNLOCK(is);
411 		return;
412 	}
413 
414 	/*
415 	 * Request immediate reconnection from iscsid(8).
416 	 */
417 	//ISCSI_SESSION_DEBUG(is, "waking up iscsid(8)");
418 	is->is_waiting_for_iscsid = true;
419 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
420 	is->is_timeout = 0;
421 	ISCSI_SESSION_UNLOCK(is);
422 	cv_signal(&is->is_softc->sc_cv);
423 }
424 
425 static void
426 iscsi_maintenance_thread_terminate(struct iscsi_session *is)
427 {
428 	struct iscsi_softc *sc;
429 
430 	sc = is->is_softc;
431 	sx_xlock(&sc->sc_lock);
432 
433 	icl_conn_close(is->is_conn);
434 	callout_drain(&is->is_callout);
435 
436 	ISCSI_SESSION_LOCK(is);
437 
438 	KASSERT(is->is_terminating, ("is_terminating == false"));
439 
440 #ifdef ICL_KERNEL_PROXY
441 	if (is->is_login_pdu != NULL) {
442 		icl_pdu_free(is->is_login_pdu);
443 		is->is_login_pdu = NULL;
444 	}
445 	cv_signal(&is->is_login_cv);
446 #endif
447 
448 	iscsi_session_cleanup(is, true);
449 
450 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
451 	    ("destroying session with active tasks"));
452 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
453 	    ("destroying session with postponed PDUs"));
454 
455 	ISCSI_SESSION_UNLOCK(is);
456 
457 	icl_conn_free(is->is_conn);
458 	mtx_destroy(&is->is_lock);
459 	cv_destroy(&is->is_maintenance_cv);
460 #ifdef ICL_KERNEL_PROXY
461 	cv_destroy(&is->is_login_cv);
462 #endif
463 	TAILQ_REMOVE(&sc->sc_sessions, is, is_next);
464 	sx_xunlock(&sc->sc_lock);
465 
466 	ISCSI_SESSION_DEBUG(is, "terminated");
467 	free(is, M_ISCSI);
468 
469 	/*
470 	 * The iscsi_unload() routine might be waiting.
471 	 */
472 	cv_signal(&sc->sc_cv);
473 }
474 
475 static void
476 iscsi_maintenance_thread(void *arg)
477 {
478 	struct iscsi_session *is;
479 
480 	is = arg;
481 
482 	for (;;) {
483 		ISCSI_SESSION_LOCK(is);
484 		if (is->is_reconnecting == false &&
485 		    is->is_terminating == false &&
486 		    STAILQ_EMPTY(&is->is_postponed))
487 			cv_wait(&is->is_maintenance_cv, &is->is_lock);
488 
489 		/* Terminate supersedes reconnect. */
490 		if (is->is_terminating) {
491 			ISCSI_SESSION_UNLOCK(is);
492 			iscsi_maintenance_thread_terminate(is);
493 			kthread_exit();
494 			return;
495 		}
496 
497 		if (is->is_reconnecting) {
498 			ISCSI_SESSION_UNLOCK(is);
499 			iscsi_maintenance_thread_reconnect(is);
500 			continue;
501 		}
502 
503 		iscsi_session_send_postponed(is);
504 		ISCSI_SESSION_UNLOCK(is);
505 	}
506 }
507 
508 static void
509 iscsi_session_reconnect(struct iscsi_session *is)
510 {
511 
512 	/*
513 	 * XXX: We can't use locking here, because
514 	 * 	it's being called from various contexts.
515 	 * 	Hope it doesn't break anything.
516 	 */
517 	if (is->is_reconnecting)
518 		return;
519 
520 	is->is_reconnecting = true;
521 	cv_signal(&is->is_maintenance_cv);
522 }
523 
524 static void
525 iscsi_session_terminate(struct iscsi_session *is)
526 {
527 
528 	if (is->is_terminating)
529 		return;
530 
531 	is->is_terminating = true;
532 
533 #if 0
534 	iscsi_session_logout(is);
535 #endif
536 	cv_signal(&is->is_maintenance_cv);
537 }
538 
539 static void
540 iscsi_callout(void *context)
541 {
542 	struct icl_pdu *request;
543 	struct iscsi_bhs_nop_out *bhsno;
544 	struct iscsi_session *is;
545 	bool reconnect_needed = false;
546 
547 	is = context;
548 
549 	ISCSI_SESSION_LOCK(is);
550 	if (is->is_terminating) {
551 		ISCSI_SESSION_UNLOCK(is);
552 		return;
553 	}
554 
555 	callout_schedule(&is->is_callout, 1 * hz);
556 
557 	if (is->is_conf.isc_enable == 0)
558 		goto out;
559 
560 	is->is_timeout++;
561 
562 	if (is->is_waiting_for_iscsid) {
563 		if (iscsid_timeout > 0 && is->is_timeout > iscsid_timeout) {
564 			ISCSI_SESSION_WARN(is, "timed out waiting for iscsid(8) "
565 			    "for %d seconds; reconnecting",
566 			    is->is_timeout);
567 			reconnect_needed = true;
568 		}
569 		goto out;
570 	}
571 
572 	if (is->is_login_phase) {
573 		if (login_timeout > 0 && is->is_timeout > login_timeout) {
574 			ISCSI_SESSION_WARN(is, "login timed out after %d seconds; "
575 			    "reconnecting", is->is_timeout);
576 			reconnect_needed = true;
577 		}
578 		goto out;
579 	}
580 
581 	if (ping_timeout <= 0) {
582 		/*
583 		 * Pings are disabled.  Don't send NOP-Out in this case.
584 		 * Reset the timeout, to avoid triggering reconnection,
585 		 * should the user decide to reenable them.
586 		 */
587 		is->is_timeout = 0;
588 		goto out;
589 	}
590 
591 	if (is->is_timeout >= ping_timeout) {
592 		ISCSI_SESSION_WARN(is, "no ping reply (NOP-In) after %d seconds; "
593 		    "reconnecting", ping_timeout);
594 		reconnect_needed = true;
595 		goto out;
596 	}
597 
598 	ISCSI_SESSION_UNLOCK(is);
599 
600 	/*
601 	 * If the ping was reset less than one second ago - which means
602 	 * that we've received some PDU during the last second - assume
603 	 * the traffic flows correctly and don't bother sending a NOP-Out.
604 	 *
605 	 * (It's 2 - one for one second, and one for incrementing is_timeout
606 	 * earlier in this routine.)
607 	 */
608 	if (is->is_timeout < 2)
609 		return;
610 
611 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
612 	if (request == NULL) {
613 		ISCSI_SESSION_WARN(is, "failed to allocate PDU");
614 		return;
615 	}
616 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
617 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
618 	    ISCSI_BHS_OPCODE_IMMEDIATE;
619 	bhsno->bhsno_flags = 0x80;
620 	bhsno->bhsno_target_transfer_tag = 0xffffffff;
621 	iscsi_pdu_queue(request);
622 	return;
623 
624 out:
625 	if (is->is_terminating) {
626 		ISCSI_SESSION_UNLOCK(is);
627 		return;
628 	}
629 
630 	ISCSI_SESSION_UNLOCK(is);
631 
632 	if (reconnect_needed)
633 		iscsi_session_reconnect(is);
634 }
635 
636 static void
637 iscsi_pdu_update_statsn(const struct icl_pdu *response)
638 {
639 	const struct iscsi_bhs_data_in *bhsdi;
640 	struct iscsi_session *is;
641 	uint32_t expcmdsn, maxcmdsn, statsn;
642 
643 	is = PDU_SESSION(response);
644 
645 	ISCSI_SESSION_LOCK_ASSERT(is);
646 
647 	/*
648 	 * We're only using fields common for all the response
649 	 * (target -> initiator) PDUs.
650 	 */
651 	bhsdi = (const struct iscsi_bhs_data_in *)response->ip_bhs;
652 	/*
653 	 * Ok, I lied.  In case of Data-In, "The fields StatSN, Status,
654 	 * and Residual Count only have meaningful content if the S bit
655 	 * is set to 1", so we also need to check the bit specific for
656 	 * Data-In PDU.
657 	 */
658 	if (bhsdi->bhsdi_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_IN ||
659 	    (bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0) {
660 		statsn = ntohl(bhsdi->bhsdi_statsn);
661 		if (statsn != is->is_statsn && statsn != (is->is_statsn + 1)) {
662 			/* XXX: This is normal situation for MCS */
663 			ISCSI_SESSION_WARN(is, "PDU 0x%x StatSN %u != "
664 			    "session ExpStatSN %u (or + 1); reconnecting",
665 			    bhsdi->bhsdi_opcode, statsn, is->is_statsn);
666 			iscsi_session_reconnect(is);
667 		}
668 		if (ISCSI_SNGT(statsn, is->is_statsn))
669 			is->is_statsn = statsn;
670 	}
671 
672 	expcmdsn = ntohl(bhsdi->bhsdi_expcmdsn);
673 	maxcmdsn = ntohl(bhsdi->bhsdi_maxcmdsn);
674 
675 	if (ISCSI_SNLT(maxcmdsn + 1, expcmdsn)) {
676 		ISCSI_SESSION_DEBUG(is,
677 		    "PDU MaxCmdSN %u + 1 < PDU ExpCmdSN %u; ignoring",
678 		    maxcmdsn, expcmdsn);
679 	} else {
680 		if (ISCSI_SNGT(maxcmdsn, is->is_maxcmdsn)) {
681 			is->is_maxcmdsn = maxcmdsn;
682 
683 			/*
684 			 * Command window increased; kick the maintanance thread
685 			 * to send out postponed commands.
686 			 */
687 			if (!STAILQ_EMPTY(&is->is_postponed))
688 				cv_signal(&is->is_maintenance_cv);
689 		} else if (ISCSI_SNLT(maxcmdsn, is->is_maxcmdsn)) {
690 			/* XXX: This is normal situation for MCS */
691 			ISCSI_SESSION_DEBUG(is,
692 			    "PDU MaxCmdSN %u < session MaxCmdSN %u; ignoring",
693 			    maxcmdsn, is->is_maxcmdsn);
694 		}
695 
696 		if (ISCSI_SNGT(expcmdsn, is->is_expcmdsn)) {
697 			is->is_expcmdsn = expcmdsn;
698 		} else if (ISCSI_SNLT(expcmdsn, is->is_expcmdsn)) {
699 			/* XXX: This is normal situation for MCS */
700 			ISCSI_SESSION_DEBUG(is,
701 			    "PDU ExpCmdSN %u < session ExpCmdSN %u; ignoring",
702 			    expcmdsn, is->is_expcmdsn);
703 		}
704 	}
705 
706 	/*
707 	 * Every incoming PDU - not just NOP-In - resets the ping timer.
708 	 * The purpose of the timeout is to reset the connection when it stalls;
709 	 * we don't want this to happen when NOP-In or NOP-Out ends up delayed
710 	 * in some queue.
711 	 */
712 	is->is_timeout = 0;
713 }
714 
715 static void
716 iscsi_receive_callback(struct icl_pdu *response)
717 {
718 	struct iscsi_session *is;
719 
720 	is = PDU_SESSION(response);
721 
722 	ISCSI_SESSION_LOCK(is);
723 
724 	iscsi_pdu_update_statsn(response);
725 
726 #ifdef ICL_KERNEL_PROXY
727 	if (is->is_login_phase) {
728 		if (is->is_login_pdu == NULL)
729 			is->is_login_pdu = response;
730 		else
731 			icl_pdu_free(response);
732 		ISCSI_SESSION_UNLOCK(is);
733 		cv_signal(&is->is_login_cv);
734 		return;
735 	}
736 #endif
737 
738 	/*
739 	 * The handling routine is responsible for freeing the PDU
740 	 * when it's no longer needed.
741 	 */
742 	switch (response->ip_bhs->bhs_opcode) {
743 	case ISCSI_BHS_OPCODE_NOP_IN:
744 		iscsi_pdu_handle_nop_in(response);
745 		ISCSI_SESSION_UNLOCK(is);
746 		break;
747 	case ISCSI_BHS_OPCODE_SCSI_RESPONSE:
748 		iscsi_pdu_handle_scsi_response(response);
749 		/* Session lock dropped inside. */
750 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
751 		break;
752 	case ISCSI_BHS_OPCODE_TASK_RESPONSE:
753 		iscsi_pdu_handle_task_response(response);
754 		ISCSI_SESSION_UNLOCK(is);
755 		break;
756 	case ISCSI_BHS_OPCODE_SCSI_DATA_IN:
757 		iscsi_pdu_handle_data_in(response);
758 		/* Session lock dropped inside. */
759 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
760 		break;
761 	case ISCSI_BHS_OPCODE_LOGOUT_RESPONSE:
762 		iscsi_pdu_handle_logout_response(response);
763 		ISCSI_SESSION_UNLOCK(is);
764 		break;
765 	case ISCSI_BHS_OPCODE_R2T:
766 		iscsi_pdu_handle_r2t(response);
767 		ISCSI_SESSION_UNLOCK(is);
768 		break;
769 	case ISCSI_BHS_OPCODE_ASYNC_MESSAGE:
770 		iscsi_pdu_handle_async_message(response);
771 		ISCSI_SESSION_UNLOCK(is);
772 		break;
773 	case ISCSI_BHS_OPCODE_REJECT:
774 		iscsi_pdu_handle_reject(response);
775 		ISCSI_SESSION_UNLOCK(is);
776 		break;
777 	default:
778 		ISCSI_SESSION_WARN(is, "received PDU with unsupported "
779 		    "opcode 0x%x; reconnecting",
780 		    response->ip_bhs->bhs_opcode);
781 		iscsi_session_reconnect(is);
782 		ISCSI_SESSION_UNLOCK(is);
783 		icl_pdu_free(response);
784 	}
785 }
786 
787 static void
788 iscsi_error_callback(struct icl_conn *ic)
789 {
790 	struct iscsi_session *is;
791 
792 	is = CONN_SESSION(ic);
793 
794 	ISCSI_SESSION_WARN(is, "connection error; reconnecting");
795 	iscsi_session_reconnect(is);
796 }
797 
798 static void
799 iscsi_pdu_handle_nop_in(struct icl_pdu *response)
800 {
801 	struct iscsi_session *is;
802 	struct iscsi_bhs_nop_out *bhsno;
803 	struct iscsi_bhs_nop_in *bhsni;
804 	struct icl_pdu *request;
805 	void *data = NULL;
806 	size_t datasize;
807 	int error;
808 
809 	is = PDU_SESSION(response);
810 	bhsni = (struct iscsi_bhs_nop_in *)response->ip_bhs;
811 
812 	if (bhsni->bhsni_target_transfer_tag == 0xffffffff) {
813 		/*
814 		 * Nothing to do; iscsi_pdu_update_statsn() already
815 		 * zeroed the timeout.
816 		 */
817 		icl_pdu_free(response);
818 		return;
819 	}
820 
821 	datasize = icl_pdu_data_segment_length(response);
822 	if (datasize > 0) {
823 		data = malloc(datasize, M_ISCSI, M_NOWAIT | M_ZERO);
824 		if (data == NULL) {
825 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
826 			    "reconnecting");
827 			icl_pdu_free(response);
828 			iscsi_session_reconnect(is);
829 			return;
830 		}
831 		icl_pdu_get_data(response, 0, data, datasize);
832 	}
833 
834 	request = icl_pdu_new(response->ip_conn, M_NOWAIT);
835 	if (request == NULL) {
836 		ISCSI_SESSION_WARN(is, "failed to allocate memory; "
837 		    "reconnecting");
838 		free(data, M_ISCSI);
839 		icl_pdu_free(response);
840 		iscsi_session_reconnect(is);
841 		return;
842 	}
843 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
844 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
845 	    ISCSI_BHS_OPCODE_IMMEDIATE;
846 	bhsno->bhsno_flags = 0x80;
847 	bhsno->bhsno_initiator_task_tag = 0xffffffff;
848 	bhsno->bhsno_target_transfer_tag = bhsni->bhsni_target_transfer_tag;
849 	if (datasize > 0) {
850 		error = icl_pdu_append_data(request, data, datasize, M_NOWAIT);
851 		if (error != 0) {
852 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
853 			    "reconnecting");
854 			free(data, M_ISCSI);
855 			icl_pdu_free(request);
856 			icl_pdu_free(response);
857 			iscsi_session_reconnect(is);
858 			return;
859 		}
860 		free(data, M_ISCSI);
861 	}
862 
863 	icl_pdu_free(response);
864 	iscsi_pdu_queue_locked(request);
865 }
866 
867 static void
868 iscsi_pdu_handle_scsi_response(struct icl_pdu *response)
869 {
870 	struct iscsi_bhs_scsi_response *bhssr;
871 	struct iscsi_outstanding *io;
872 	struct iscsi_session *is;
873 	union ccb *ccb;
874 	struct ccb_scsiio *csio;
875 	size_t data_segment_len, received;
876 	uint16_t sense_len;
877 	uint32_t resid;
878 
879 	is = PDU_SESSION(response);
880 
881 	bhssr = (struct iscsi_bhs_scsi_response *)response->ip_bhs;
882 	io = iscsi_outstanding_find(is, bhssr->bhssr_initiator_task_tag);
883 	if (io == NULL || io->io_ccb == NULL) {
884 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhssr->bhssr_initiator_task_tag);
885 		icl_pdu_free(response);
886 		iscsi_session_reconnect(is);
887 		ISCSI_SESSION_UNLOCK(is);
888 		return;
889 	}
890 
891 	ccb = io->io_ccb;
892 
893 	/*
894 	 * With iSER, after getting good response we can be sure
895 	 * that all the data has been successfully transferred.
896 	 */
897 	if (is->is_conn->ic_iser) {
898 		resid = ntohl(bhssr->bhssr_residual_count);
899 		if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW) {
900 			io->io_received = ccb->csio.dxfer_len - resid;
901 		} else if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_OVERFLOW) {
902 			ISCSI_SESSION_WARN(is, "overflow: target indicates %d", resid);
903 		} else {
904 			io->io_received = ccb->csio.dxfer_len;
905 		}
906 	}
907 
908 	received = io->io_received;
909 	iscsi_outstanding_remove(is, io);
910 	ISCSI_SESSION_UNLOCK(is);
911 
912 	if (bhssr->bhssr_response != BHSSR_RESPONSE_COMMAND_COMPLETED) {
913 		ISCSI_SESSION_WARN(is, "service response 0x%x", bhssr->bhssr_response);
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 	} else if (bhssr->bhssr_status == 0) {
920 		ccb->ccb_h.status = CAM_REQ_CMP;
921 	} else {
922  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
923  			xpt_freeze_devq(ccb->ccb_h.path, 1);
924 			ISCSI_SESSION_DEBUG(is, "freezing devq");
925 		}
926  		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
927 		ccb->csio.scsi_status = bhssr->bhssr_status;
928 	}
929 
930 	csio = &ccb->csio;
931 	data_segment_len = icl_pdu_data_segment_length(response);
932 	if (data_segment_len > 0) {
933 		if (data_segment_len < sizeof(sense_len)) {
934 			ISCSI_SESSION_WARN(is, "truncated data segment (%zd bytes)",
935 			    data_segment_len);
936 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
937 				xpt_freeze_devq(ccb->ccb_h.path, 1);
938 				ISCSI_SESSION_DEBUG(is, "freezing devq");
939 			}
940 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
941 			goto out;
942 		}
943 		icl_pdu_get_data(response, 0, &sense_len, sizeof(sense_len));
944 		sense_len = ntohs(sense_len);
945 #if 0
946 		ISCSI_SESSION_DEBUG(is, "sense_len %d, data len %zd",
947 		    sense_len, data_segment_len);
948 #endif
949 		if (sizeof(sense_len) + sense_len > data_segment_len) {
950 			ISCSI_SESSION_WARN(is, "truncated data segment "
951 			    "(%zd bytes, should be %zd)",
952 			    data_segment_len, sizeof(sense_len) + sense_len);
953 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
954 				xpt_freeze_devq(ccb->ccb_h.path, 1);
955 				ISCSI_SESSION_DEBUG(is, "freezing devq");
956 			}
957 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
958 			goto out;
959 		} else if (sizeof(sense_len) + sense_len < data_segment_len)
960 			ISCSI_SESSION_WARN(is, "oversize data segment "
961 			    "(%zd bytes, should be %zd)",
962 			    data_segment_len, sizeof(sense_len) + sense_len);
963 		if (sense_len > csio->sense_len) {
964 			ISCSI_SESSION_DEBUG(is, "truncating sense from %d to %d",
965 			    sense_len, csio->sense_len);
966 			sense_len = csio->sense_len;
967 		}
968 		icl_pdu_get_data(response, sizeof(sense_len), &csio->sense_data, sense_len);
969 		csio->sense_resid = csio->sense_len - sense_len;
970 		ccb->ccb_h.status |= CAM_AUTOSNS_VALID;
971 	}
972 
973 out:
974 	if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW)
975 		csio->resid = ntohl(bhssr->bhssr_residual_count);
976 
977 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
978 		KASSERT(received <= csio->dxfer_len,
979 		    ("received > csio->dxfer_len"));
980 		if (received < csio->dxfer_len) {
981 			if (csio->resid != csio->dxfer_len - received) {
982 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
983 				    "target indicates %d, we calculated %zd",
984 				    csio->resid, csio->dxfer_len - received);
985 			}
986 			csio->resid = csio->dxfer_len - received;
987 		}
988 	}
989 
990 	xpt_done(ccb);
991 	icl_pdu_free(response);
992 }
993 
994 static void
995 iscsi_pdu_handle_task_response(struct icl_pdu *response)
996 {
997 	struct iscsi_bhs_task_management_response *bhstmr;
998 	struct iscsi_outstanding *io, *aio;
999 	struct iscsi_session *is;
1000 
1001 	is = PDU_SESSION(response);
1002 
1003 	bhstmr = (struct iscsi_bhs_task_management_response *)response->ip_bhs;
1004 	io = iscsi_outstanding_find(is, bhstmr->bhstmr_initiator_task_tag);
1005 	if (io == NULL || io->io_ccb != NULL) {
1006 		ISCSI_SESSION_WARN(is, "bad itt 0x%x",
1007 		    bhstmr->bhstmr_initiator_task_tag);
1008 		icl_pdu_free(response);
1009 		iscsi_session_reconnect(is);
1010 		return;
1011 	}
1012 
1013 	if (bhstmr->bhstmr_response != BHSTMR_RESPONSE_FUNCTION_COMPLETE) {
1014 		ISCSI_SESSION_WARN(is, "task response 0x%x",
1015 		    bhstmr->bhstmr_response);
1016 	} else {
1017 		aio = iscsi_outstanding_find(is, io->io_datasn);
1018 		if (aio != NULL && aio->io_ccb != NULL)
1019 			iscsi_session_terminate_task(is, aio, false);
1020 	}
1021 
1022 	iscsi_outstanding_remove(is, io);
1023 	icl_pdu_free(response);
1024 }
1025 
1026 static void
1027 iscsi_pdu_handle_data_in(struct icl_pdu *response)
1028 {
1029 	struct iscsi_bhs_data_in *bhsdi;
1030 	struct iscsi_outstanding *io;
1031 	struct iscsi_session *is;
1032 	union ccb *ccb;
1033 	struct ccb_scsiio *csio;
1034 	size_t data_segment_len, received, oreceived;
1035 
1036 	is = PDU_SESSION(response);
1037 	bhsdi = (struct iscsi_bhs_data_in *)response->ip_bhs;
1038 	io = iscsi_outstanding_find(is, bhsdi->bhsdi_initiator_task_tag);
1039 	if (io == NULL || io->io_ccb == NULL) {
1040 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhsdi->bhsdi_initiator_task_tag);
1041 		icl_pdu_free(response);
1042 		iscsi_session_reconnect(is);
1043 		ISCSI_SESSION_UNLOCK(is);
1044 		return;
1045 	}
1046 
1047 	data_segment_len = icl_pdu_data_segment_length(response);
1048 	if (data_segment_len == 0) {
1049 		/*
1050 		 * "The sending of 0 length data segments should be avoided,
1051 		 * but initiators and targets MUST be able to properly receive
1052 		 * 0 length data segments."
1053 		 */
1054 		ISCSI_SESSION_UNLOCK(is);
1055 		icl_pdu_free(response);
1056 		return;
1057 	}
1058 
1059 	/*
1060 	 * We need to track this for security reasons - without it, malicious target
1061 	 * could respond to SCSI READ without sending Data-In PDUs, which would result
1062 	 * in read operation on the initiator side returning random kernel data.
1063 	 */
1064 	if (ntohl(bhsdi->bhsdi_buffer_offset) != io->io_received) {
1065 		ISCSI_SESSION_WARN(is, "data out of order; expected offset %zd, got %zd",
1066 		    io->io_received, (size_t)ntohl(bhsdi->bhsdi_buffer_offset));
1067 		icl_pdu_free(response);
1068 		iscsi_session_reconnect(is);
1069 		ISCSI_SESSION_UNLOCK(is);
1070 		return;
1071 	}
1072 
1073 	ccb = io->io_ccb;
1074 	csio = &ccb->csio;
1075 
1076 	if (io->io_received + data_segment_len > csio->dxfer_len) {
1077 		ISCSI_SESSION_WARN(is, "oversize data segment (%zd bytes "
1078 		    "at offset %zd, buffer is %d)",
1079 		    data_segment_len, io->io_received, csio->dxfer_len);
1080 		icl_pdu_free(response);
1081 		iscsi_session_reconnect(is);
1082 		ISCSI_SESSION_UNLOCK(is);
1083 		return;
1084 	}
1085 
1086 	oreceived = io->io_received;
1087 	io->io_received += data_segment_len;
1088 	received = io->io_received;
1089 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0)
1090 		iscsi_outstanding_remove(is, io);
1091 	ISCSI_SESSION_UNLOCK(is);
1092 
1093 	icl_pdu_get_data(response, 0, csio->data_ptr + oreceived, data_segment_len);
1094 
1095 	/*
1096 	 * XXX: Check DataSN.
1097 	 * XXX: Check F.
1098 	 */
1099 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) == 0) {
1100 		/*
1101 		 * Nothing more to do.
1102 		 */
1103 		icl_pdu_free(response);
1104 		return;
1105 	}
1106 
1107 	//ISCSI_SESSION_DEBUG(is, "got S flag; status 0x%x", bhsdi->bhsdi_status);
1108 	if (bhsdi->bhsdi_status == 0) {
1109 		ccb->ccb_h.status = CAM_REQ_CMP;
1110 	} else {
1111 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
1112 			xpt_freeze_devq(ccb->ccb_h.path, 1);
1113 			ISCSI_SESSION_DEBUG(is, "freezing devq");
1114 		}
1115 		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
1116 		csio->scsi_status = bhsdi->bhsdi_status;
1117 	}
1118 
1119 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
1120 		KASSERT(received <= csio->dxfer_len,
1121 		    ("received > csio->dxfer_len"));
1122 		if (received < csio->dxfer_len) {
1123 			csio->resid = ntohl(bhsdi->bhsdi_residual_count);
1124 			if (csio->resid != csio->dxfer_len - received) {
1125 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
1126 				    "target indicates %d, we calculated %zd",
1127 				    csio->resid, csio->dxfer_len - received);
1128 			}
1129 			csio->resid = csio->dxfer_len - received;
1130 		}
1131 	}
1132 
1133 	xpt_done(ccb);
1134 	icl_pdu_free(response);
1135 }
1136 
1137 static void
1138 iscsi_pdu_handle_logout_response(struct icl_pdu *response)
1139 {
1140 
1141 	ISCSI_SESSION_DEBUG(PDU_SESSION(response), "logout response");
1142 	icl_pdu_free(response);
1143 }
1144 
1145 static void
1146 iscsi_pdu_handle_r2t(struct icl_pdu *response)
1147 {
1148 	struct icl_pdu *request;
1149 	struct iscsi_session *is;
1150 	struct iscsi_bhs_r2t *bhsr2t;
1151 	struct iscsi_bhs_data_out *bhsdo;
1152 	struct iscsi_outstanding *io;
1153 	struct ccb_scsiio *csio;
1154 	size_t off, len, total_len;
1155 	int error;
1156 
1157 	is = PDU_SESSION(response);
1158 
1159 	bhsr2t = (struct iscsi_bhs_r2t *)response->ip_bhs;
1160 	io = iscsi_outstanding_find(is, bhsr2t->bhsr2t_initiator_task_tag);
1161 	if (io == NULL || io->io_ccb == NULL) {
1162 		ISCSI_SESSION_WARN(is, "bad itt 0x%x; reconnecting",
1163 		    bhsr2t->bhsr2t_initiator_task_tag);
1164 		icl_pdu_free(response);
1165 		iscsi_session_reconnect(is);
1166 		return;
1167 	}
1168 
1169 	csio = &io->io_ccb->csio;
1170 
1171 	if ((csio->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_OUT) {
1172 		ISCSI_SESSION_WARN(is, "received R2T for read command; reconnecting");
1173 		icl_pdu_free(response);
1174 		iscsi_session_reconnect(is);
1175 		return;
1176 	}
1177 
1178 	/*
1179 	 * XXX: Verify R2TSN.
1180 	 */
1181 
1182 	io->io_datasn = 0;
1183 
1184 	off = ntohl(bhsr2t->bhsr2t_buffer_offset);
1185 	if (off > csio->dxfer_len) {
1186 		ISCSI_SESSION_WARN(is, "target requested invalid offset "
1187 		    "%zd, buffer is is %d; reconnecting", off, csio->dxfer_len);
1188 		icl_pdu_free(response);
1189 		iscsi_session_reconnect(is);
1190 		return;
1191 	}
1192 
1193 	total_len = ntohl(bhsr2t->bhsr2t_desired_data_transfer_length);
1194 	if (total_len == 0 || total_len > csio->dxfer_len) {
1195 		ISCSI_SESSION_WARN(is, "target requested invalid length "
1196 		    "%zd, buffer is %d; reconnecting", total_len, csio->dxfer_len);
1197 		icl_pdu_free(response);
1198 		iscsi_session_reconnect(is);
1199 		return;
1200 	}
1201 
1202 	//ISCSI_SESSION_DEBUG(is, "r2t; off %zd, len %zd", off, total_len);
1203 
1204 	for (;;) {
1205 		len = total_len;
1206 
1207 		if (len > is->is_max_data_segment_length)
1208 			len = is->is_max_data_segment_length;
1209 
1210 		if (off + len > csio->dxfer_len) {
1211 			ISCSI_SESSION_WARN(is, "target requested invalid "
1212 			    "length/offset %zd, buffer is %d; reconnecting",
1213 			    off + len, csio->dxfer_len);
1214 			icl_pdu_free(response);
1215 			iscsi_session_reconnect(is);
1216 			return;
1217 		}
1218 
1219 		request = icl_pdu_new(response->ip_conn, M_NOWAIT);
1220 		if (request == NULL) {
1221 			icl_pdu_free(response);
1222 			iscsi_session_reconnect(is);
1223 			return;
1224 		}
1225 
1226 		bhsdo = (struct iscsi_bhs_data_out *)request->ip_bhs;
1227 		bhsdo->bhsdo_opcode = ISCSI_BHS_OPCODE_SCSI_DATA_OUT;
1228 		bhsdo->bhsdo_lun = bhsr2t->bhsr2t_lun;
1229 		bhsdo->bhsdo_initiator_task_tag =
1230 		    bhsr2t->bhsr2t_initiator_task_tag;
1231 		bhsdo->bhsdo_target_transfer_tag =
1232 		    bhsr2t->bhsr2t_target_transfer_tag;
1233 		bhsdo->bhsdo_datasn = htonl(io->io_datasn++);
1234 		bhsdo->bhsdo_buffer_offset = htonl(off);
1235 		error = icl_pdu_append_data(request, csio->data_ptr + off, len,
1236 		    M_NOWAIT);
1237 		if (error != 0) {
1238 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
1239 			    "reconnecting");
1240 			icl_pdu_free(request);
1241 			icl_pdu_free(response);
1242 			iscsi_session_reconnect(is);
1243 			return;
1244 		}
1245 
1246 		off += len;
1247 		total_len -= len;
1248 
1249 		if (total_len == 0) {
1250 			bhsdo->bhsdo_flags |= BHSDO_FLAGS_F;
1251 			//ISCSI_SESSION_DEBUG(is, "setting F, off %zd", off);
1252 		} else {
1253 			//ISCSI_SESSION_DEBUG(is, "not finished, off %zd", off);
1254 		}
1255 
1256 		iscsi_pdu_queue_locked(request);
1257 
1258 		if (total_len == 0)
1259 			break;
1260 	}
1261 
1262 	icl_pdu_free(response);
1263 }
1264 
1265 static void
1266 iscsi_pdu_handle_async_message(struct icl_pdu *response)
1267 {
1268 	struct iscsi_bhs_asynchronous_message *bhsam;
1269 	struct iscsi_session *is;
1270 
1271 	is = PDU_SESSION(response);
1272 	bhsam = (struct iscsi_bhs_asynchronous_message *)response->ip_bhs;
1273 	switch (bhsam->bhsam_async_event) {
1274 	case BHSAM_EVENT_TARGET_REQUESTS_LOGOUT:
1275 		ISCSI_SESSION_WARN(is, "target requests logout; removing session");
1276 		iscsi_session_logout(is);
1277 		iscsi_session_terminate(is);
1278 		break;
1279 	case BHSAM_EVENT_TARGET_TERMINATES_CONNECTION:
1280 		ISCSI_SESSION_WARN(is, "target indicates it will drop drop the connection");
1281 		break;
1282 	case BHSAM_EVENT_TARGET_TERMINATES_SESSION:
1283 		ISCSI_SESSION_WARN(is, "target indicates it will drop drop the session");
1284 		break;
1285 	default:
1286 		/*
1287 		 * XXX: Technically, we're obligated to also handle
1288 		 * 	parameter renegotiation.
1289 		 */
1290 		ISCSI_SESSION_WARN(is, "ignoring AsyncEvent %d", bhsam->bhsam_async_event);
1291 		break;
1292 	}
1293 
1294 	icl_pdu_free(response);
1295 }
1296 
1297 static void
1298 iscsi_pdu_handle_reject(struct icl_pdu *response)
1299 {
1300 	struct iscsi_bhs_reject *bhsr;
1301 	struct iscsi_session *is;
1302 
1303 	is = PDU_SESSION(response);
1304 	bhsr = (struct iscsi_bhs_reject *)response->ip_bhs;
1305 	ISCSI_SESSION_WARN(is, "received Reject PDU, reason 0x%x; protocol error?",
1306 	    bhsr->bhsr_reason);
1307 
1308 	icl_pdu_free(response);
1309 }
1310 
1311 static int
1312 iscsi_ioctl_daemon_wait(struct iscsi_softc *sc,
1313     struct iscsi_daemon_request *request)
1314 {
1315 	struct iscsi_session *is;
1316 	int error;
1317 
1318 	sx_slock(&sc->sc_lock);
1319 	for (;;) {
1320 		TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1321 			ISCSI_SESSION_LOCK(is);
1322 			if (is->is_conf.isc_enable == 0 &&
1323 			    is->is_conf.isc_discovery == 0) {
1324 				ISCSI_SESSION_UNLOCK(is);
1325 				continue;
1326 			}
1327 			if (is->is_waiting_for_iscsid)
1328 				break;
1329 			ISCSI_SESSION_UNLOCK(is);
1330 		}
1331 
1332 		if (is == NULL) {
1333 			/*
1334 			 * No session requires attention from iscsid(8); wait.
1335 			 */
1336 			error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
1337 			if (error != 0) {
1338 				sx_sunlock(&sc->sc_lock);
1339 				return (error);
1340 			}
1341 			continue;
1342 		}
1343 
1344 		is->is_waiting_for_iscsid = false;
1345 		is->is_login_phase = true;
1346 		is->is_reason[0] = '\0';
1347 		ISCSI_SESSION_UNLOCK(is);
1348 
1349 		request->idr_session_id = is->is_id;
1350 		memcpy(&request->idr_isid, &is->is_isid,
1351 		    sizeof(request->idr_isid));
1352 		request->idr_tsih = 0;	/* New or reinstated session. */
1353 		memcpy(&request->idr_conf, &is->is_conf,
1354 		    sizeof(request->idr_conf));
1355 
1356 		error = icl_limits(is->is_conf.isc_offload,
1357 		    is->is_conf.isc_iser,
1358 		    &request->idr_limits.isl_max_data_segment_length);
1359 		if (error != 0) {
1360 			ISCSI_SESSION_WARN(is, "icl_limits for offload \"%s\" "
1361 			    "failed with error %d", is->is_conf.isc_offload,
1362 			    error);
1363 			sx_sunlock(&sc->sc_lock);
1364 			return (error);
1365 		}
1366 
1367 		sx_sunlock(&sc->sc_lock);
1368 		return (0);
1369 	}
1370 }
1371 
1372 static int
1373 iscsi_ioctl_daemon_handoff(struct iscsi_softc *sc,
1374     struct iscsi_daemon_handoff *handoff)
1375 {
1376 	struct iscsi_session *is;
1377 	struct icl_conn *ic;
1378 	int error;
1379 
1380 	sx_slock(&sc->sc_lock);
1381 
1382 	/*
1383 	 * Find the session to hand off socket to.
1384 	 */
1385 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1386 		if (is->is_id == handoff->idh_session_id)
1387 			break;
1388 	}
1389 	if (is == NULL) {
1390 		sx_sunlock(&sc->sc_lock);
1391 		return (ESRCH);
1392 	}
1393 	ISCSI_SESSION_LOCK(is);
1394 	ic = is->is_conn;
1395 	if (is->is_conf.isc_discovery || is->is_terminating) {
1396 		ISCSI_SESSION_UNLOCK(is);
1397 		sx_sunlock(&sc->sc_lock);
1398 		return (EINVAL);
1399 	}
1400 	if (is->is_connected) {
1401 		/*
1402 		 * This might have happened because another iscsid(8)
1403 		 * instance handed off the connection in the meantime.
1404 		 * Just return.
1405 		 */
1406 		ISCSI_SESSION_WARN(is, "handoff on already connected "
1407 		    "session");
1408 		ISCSI_SESSION_UNLOCK(is);
1409 		sx_sunlock(&sc->sc_lock);
1410 		return (EBUSY);
1411 	}
1412 
1413 	strlcpy(is->is_target_alias, handoff->idh_target_alias,
1414 	    sizeof(is->is_target_alias));
1415 	is->is_tsih = handoff->idh_tsih;
1416 	is->is_statsn = handoff->idh_statsn;
1417 	is->is_initial_r2t = handoff->idh_initial_r2t;
1418 	is->is_immediate_data = handoff->idh_immediate_data;
1419 
1420 	/*
1421 	 * Cap MaxRecvDataSegmentLength obtained from the target to the maximum
1422 	 * size supported by our ICL module.
1423 	 */
1424 	is->is_max_data_segment_length = min(ic->ic_max_data_segment_length,
1425 	    handoff->idh_max_data_segment_length);
1426 	is->is_max_burst_length = handoff->idh_max_burst_length;
1427 	is->is_first_burst_length = handoff->idh_first_burst_length;
1428 
1429 	if (handoff->idh_header_digest == ISCSI_DIGEST_CRC32C)
1430 		ic->ic_header_crc32c = true;
1431 	else
1432 		ic->ic_header_crc32c = false;
1433 	if (handoff->idh_data_digest == ISCSI_DIGEST_CRC32C)
1434 		ic->ic_data_crc32c = true;
1435 	else
1436 		ic->ic_data_crc32c = false;
1437 	ic->ic_maxtags = maxtags;
1438 
1439 	is->is_cmdsn = 0;
1440 	is->is_expcmdsn = 0;
1441 	is->is_maxcmdsn = 0;
1442 	is->is_waiting_for_iscsid = false;
1443 	is->is_login_phase = false;
1444 	is->is_timeout = 0;
1445 	is->is_connected = true;
1446 	is->is_reason[0] = '\0';
1447 
1448 	ISCSI_SESSION_UNLOCK(is);
1449 
1450 	/*
1451 	 * If we're going through the proxy, the idh_socket will be 0,
1452 	 * and the ICL module can simply ignore this call.  It can also
1453 	 * use it to determine it's no longer in the Login phase.
1454 	 */
1455 	error = icl_conn_handoff(ic, handoff->idh_socket);
1456 	if (error != 0) {
1457 		sx_sunlock(&sc->sc_lock);
1458 		iscsi_session_terminate(is);
1459 		return (error);
1460 	}
1461 
1462 	sx_sunlock(&sc->sc_lock);
1463 
1464 	if (is->is_sim != NULL) {
1465 		/*
1466 		 * When reconnecting, there already is SIM allocated for the session.
1467 		 */
1468 		KASSERT(is->is_simq_frozen, ("reconnect without frozen simq"));
1469 		ISCSI_SESSION_LOCK(is);
1470 		ISCSI_SESSION_DEBUG(is, "releasing");
1471 		xpt_release_simq(is->is_sim, 1);
1472 		is->is_simq_frozen = false;
1473 		ISCSI_SESSION_UNLOCK(is);
1474 
1475 	} else {
1476 		ISCSI_SESSION_LOCK(is);
1477 		is->is_devq = cam_simq_alloc(ic->ic_maxtags);
1478 		if (is->is_devq == NULL) {
1479 			ISCSI_SESSION_WARN(is, "failed to allocate simq");
1480 			iscsi_session_terminate(is);
1481 			return (ENOMEM);
1482 		}
1483 
1484 		is->is_sim = cam_sim_alloc(iscsi_action, iscsi_poll, "iscsi",
1485 		    is, is->is_id /* unit */, &is->is_lock,
1486 		    1, ic->ic_maxtags, is->is_devq);
1487 		if (is->is_sim == NULL) {
1488 			ISCSI_SESSION_UNLOCK(is);
1489 			ISCSI_SESSION_WARN(is, "failed to allocate SIM");
1490 			cam_simq_free(is->is_devq);
1491 			iscsi_session_terminate(is);
1492 			return (ENOMEM);
1493 		}
1494 
1495 		error = xpt_bus_register(is->is_sim, NULL, 0);
1496 		if (error != 0) {
1497 			ISCSI_SESSION_UNLOCK(is);
1498 			ISCSI_SESSION_WARN(is, "failed to register bus");
1499 			iscsi_session_terminate(is);
1500 			return (ENOMEM);
1501 		}
1502 
1503 		error = xpt_create_path(&is->is_path, /*periph*/NULL,
1504 		    cam_sim_path(is->is_sim), CAM_TARGET_WILDCARD,
1505 		    CAM_LUN_WILDCARD);
1506 		if (error != CAM_REQ_CMP) {
1507 			ISCSI_SESSION_UNLOCK(is);
1508 			ISCSI_SESSION_WARN(is, "failed to create path");
1509 			iscsi_session_terminate(is);
1510 			return (ENOMEM);
1511 		}
1512 		ISCSI_SESSION_UNLOCK(is);
1513 	}
1514 
1515 	return (0);
1516 }
1517 
1518 static int
1519 iscsi_ioctl_daemon_fail(struct iscsi_softc *sc,
1520     struct iscsi_daemon_fail *fail)
1521 {
1522 	struct iscsi_session *is;
1523 
1524 	sx_slock(&sc->sc_lock);
1525 
1526 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1527 		if (is->is_id == fail->idf_session_id)
1528 			break;
1529 	}
1530 	if (is == NULL) {
1531 		sx_sunlock(&sc->sc_lock);
1532 		return (ESRCH);
1533 	}
1534 	ISCSI_SESSION_LOCK(is);
1535 	ISCSI_SESSION_DEBUG(is, "iscsid(8) failed: %s",
1536 	    fail->idf_reason);
1537 	strlcpy(is->is_reason, fail->idf_reason, sizeof(is->is_reason));
1538 	//is->is_waiting_for_iscsid = false;
1539 	//is->is_login_phase = true;
1540 	//iscsi_session_reconnect(is);
1541 	ISCSI_SESSION_UNLOCK(is);
1542 	sx_sunlock(&sc->sc_lock);
1543 
1544 	return (0);
1545 }
1546 
1547 #ifdef ICL_KERNEL_PROXY
1548 static int
1549 iscsi_ioctl_daemon_connect(struct iscsi_softc *sc,
1550     struct iscsi_daemon_connect *idc)
1551 {
1552 	struct iscsi_session *is;
1553 	struct sockaddr *from_sa, *to_sa;
1554 	int error;
1555 
1556 	sx_slock(&sc->sc_lock);
1557 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1558 		if (is->is_id == idc->idc_session_id)
1559 			break;
1560 	}
1561 	if (is == NULL) {
1562 		sx_sunlock(&sc->sc_lock);
1563 		return (ESRCH);
1564 	}
1565 	sx_sunlock(&sc->sc_lock);
1566 
1567 	if (idc->idc_from_addrlen > 0) {
1568 		error = getsockaddr(&from_sa, (void *)idc->idc_from_addr, idc->idc_from_addrlen);
1569 		if (error != 0) {
1570 			ISCSI_SESSION_WARN(is,
1571 			    "getsockaddr failed with error %d", error);
1572 			return (error);
1573 		}
1574 	} else {
1575 		from_sa = NULL;
1576 	}
1577 	error = getsockaddr(&to_sa, (void *)idc->idc_to_addr, idc->idc_to_addrlen);
1578 	if (error != 0) {
1579 		ISCSI_SESSION_WARN(is, "getsockaddr failed with error %d",
1580 		    error);
1581 		free(from_sa, M_SONAME);
1582 		return (error);
1583 	}
1584 
1585 	ISCSI_SESSION_LOCK(is);
1586 	is->is_statsn = 0;
1587 	is->is_cmdsn = 0;
1588 	is->is_expcmdsn = 0;
1589 	is->is_maxcmdsn = 0;
1590 	is->is_waiting_for_iscsid = false;
1591 	is->is_login_phase = true;
1592 	is->is_timeout = 0;
1593 	ISCSI_SESSION_UNLOCK(is);
1594 
1595 	error = icl_conn_connect(is->is_conn, idc->idc_domain,
1596 	    idc->idc_socktype, idc->idc_protocol, from_sa, to_sa);
1597 	free(from_sa, M_SONAME);
1598 	free(to_sa, M_SONAME);
1599 
1600 	/*
1601 	 * Digests are always disabled during login phase.
1602 	 */
1603 	is->is_conn->ic_header_crc32c = false;
1604 	is->is_conn->ic_data_crc32c = false;
1605 
1606 	return (error);
1607 }
1608 
1609 static int
1610 iscsi_ioctl_daemon_send(struct iscsi_softc *sc,
1611     struct iscsi_daemon_send *ids)
1612 {
1613 	struct iscsi_session *is;
1614 	struct icl_pdu *ip;
1615 	size_t datalen;
1616 	void *data;
1617 	int error;
1618 
1619 	sx_slock(&sc->sc_lock);
1620 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1621 		if (is->is_id == ids->ids_session_id)
1622 			break;
1623 	}
1624 	if (is == NULL) {
1625 		sx_sunlock(&sc->sc_lock);
1626 		return (ESRCH);
1627 	}
1628 	sx_sunlock(&sc->sc_lock);
1629 
1630 	if (is->is_login_phase == false)
1631 		return (EBUSY);
1632 
1633 	if (is->is_terminating || is->is_reconnecting)
1634 		return (EIO);
1635 
1636 	datalen = ids->ids_data_segment_len;
1637 	if (datalen > ISCSI_MAX_DATA_SEGMENT_LENGTH)
1638 		return (EINVAL);
1639 	if (datalen > 0) {
1640 		data = malloc(datalen, M_ISCSI, M_WAITOK);
1641 		error = copyin(ids->ids_data_segment, data, datalen);
1642 		if (error != 0) {
1643 			free(data, M_ISCSI);
1644 			return (error);
1645 		}
1646 	}
1647 
1648 	ip = icl_pdu_new(is->is_conn, M_WAITOK);
1649 	memcpy(ip->ip_bhs, ids->ids_bhs, sizeof(*ip->ip_bhs));
1650 	if (datalen > 0) {
1651 		error = icl_pdu_append_data(ip, data, datalen, M_WAITOK);
1652 		KASSERT(error == 0, ("icl_pdu_append_data(..., M_WAITOK) failed"));
1653 		free(data, M_ISCSI);
1654 	}
1655 	iscsi_pdu_queue(ip);
1656 
1657 	return (0);
1658 }
1659 
1660 static int
1661 iscsi_ioctl_daemon_receive(struct iscsi_softc *sc,
1662     struct iscsi_daemon_receive *idr)
1663 {
1664 	struct iscsi_session *is;
1665 	struct icl_pdu *ip;
1666 	void *data;
1667 	int error;
1668 
1669 	sx_slock(&sc->sc_lock);
1670 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1671 		if (is->is_id == idr->idr_session_id)
1672 			break;
1673 	}
1674 	if (is == NULL) {
1675 		sx_sunlock(&sc->sc_lock);
1676 		return (ESRCH);
1677 	}
1678 	sx_sunlock(&sc->sc_lock);
1679 
1680 	if (is->is_login_phase == false)
1681 		return (EBUSY);
1682 
1683 	ISCSI_SESSION_LOCK(is);
1684 	while (is->is_login_pdu == NULL &&
1685 	    is->is_terminating == false &&
1686 	    is->is_reconnecting == false) {
1687 		error = cv_wait_sig(&is->is_login_cv, &is->is_lock);
1688 		if (error != 0) {
1689 			ISCSI_SESSION_UNLOCK(is);
1690 			return (error);
1691 		}
1692 	}
1693 	if (is->is_terminating || is->is_reconnecting) {
1694 		ISCSI_SESSION_UNLOCK(is);
1695 		return (EIO);
1696 	}
1697 	ip = is->is_login_pdu;
1698 	is->is_login_pdu = NULL;
1699 	ISCSI_SESSION_UNLOCK(is);
1700 
1701 	if (ip->ip_data_len > idr->idr_data_segment_len) {
1702 		icl_pdu_free(ip);
1703 		return (EMSGSIZE);
1704 	}
1705 
1706 	copyout(ip->ip_bhs, idr->idr_bhs, sizeof(*ip->ip_bhs));
1707 	if (ip->ip_data_len > 0) {
1708 		data = malloc(ip->ip_data_len, M_ISCSI, M_WAITOK);
1709 		icl_pdu_get_data(ip, 0, data, ip->ip_data_len);
1710 		copyout(data, idr->idr_data_segment, ip->ip_data_len);
1711 		free(data, M_ISCSI);
1712 	}
1713 
1714 	icl_pdu_free(ip);
1715 
1716 	return (0);
1717 }
1718 #endif /* ICL_KERNEL_PROXY */
1719 
1720 static void
1721 iscsi_sanitize_session_conf(struct iscsi_session_conf *isc)
1722 {
1723 	/*
1724 	 * Just make sure all the fields are null-terminated.
1725 	 *
1726 	 * XXX: This is not particularly secure.  We should
1727 	 * 	create our own conf and then copy in relevant
1728 	 * 	fields.
1729 	 */
1730 	isc->isc_initiator[ISCSI_NAME_LEN - 1] = '\0';
1731 	isc->isc_initiator_addr[ISCSI_ADDR_LEN - 1] = '\0';
1732 	isc->isc_initiator_alias[ISCSI_ALIAS_LEN - 1] = '\0';
1733 	isc->isc_target[ISCSI_NAME_LEN - 1] = '\0';
1734 	isc->isc_target_addr[ISCSI_ADDR_LEN - 1] = '\0';
1735 	isc->isc_user[ISCSI_NAME_LEN - 1] = '\0';
1736 	isc->isc_secret[ISCSI_SECRET_LEN - 1] = '\0';
1737 	isc->isc_mutual_user[ISCSI_NAME_LEN - 1] = '\0';
1738 	isc->isc_mutual_secret[ISCSI_SECRET_LEN - 1] = '\0';
1739 }
1740 
1741 static bool
1742 iscsi_valid_session_conf(const struct iscsi_session_conf *isc)
1743 {
1744 
1745 	if (isc->isc_initiator[0] == '\0') {
1746 		ISCSI_DEBUG("empty isc_initiator");
1747 		return (false);
1748 	}
1749 
1750 	if (isc->isc_target_addr[0] == '\0') {
1751 		ISCSI_DEBUG("empty isc_target_addr");
1752 		return (false);
1753 	}
1754 
1755 	if (isc->isc_discovery != 0 && isc->isc_target[0] != 0) {
1756 		ISCSI_DEBUG("non-empty isc_target for discovery session");
1757 		return (false);
1758 	}
1759 
1760 	if (isc->isc_discovery == 0 && isc->isc_target[0] == 0) {
1761 		ISCSI_DEBUG("empty isc_target for non-discovery session");
1762 		return (false);
1763 	}
1764 
1765 	return (true);
1766 }
1767 
1768 static int
1769 iscsi_ioctl_session_add(struct iscsi_softc *sc, struct iscsi_session_add *isa)
1770 {
1771 	struct iscsi_session *is;
1772 	const struct iscsi_session *is2;
1773 	int error;
1774 
1775 	iscsi_sanitize_session_conf(&isa->isa_conf);
1776 	if (iscsi_valid_session_conf(&isa->isa_conf) == false)
1777 		return (EINVAL);
1778 
1779 	is = malloc(sizeof(*is), M_ISCSI, M_ZERO | M_WAITOK);
1780 	memcpy(&is->is_conf, &isa->isa_conf, sizeof(is->is_conf));
1781 
1782 	sx_xlock(&sc->sc_lock);
1783 
1784 	/*
1785 	 * Prevent duplicates.
1786 	 */
1787 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
1788 		if (!!is->is_conf.isc_discovery !=
1789 		    !!is2->is_conf.isc_discovery)
1790 			continue;
1791 
1792 		if (strcmp(is->is_conf.isc_target_addr,
1793 		    is2->is_conf.isc_target_addr) != 0)
1794 			continue;
1795 
1796 		if (is->is_conf.isc_discovery == 0 &&
1797 		    strcmp(is->is_conf.isc_target,
1798 		    is2->is_conf.isc_target) != 0)
1799 			continue;
1800 
1801 		sx_xunlock(&sc->sc_lock);
1802 		free(is, M_ISCSI);
1803 		return (EBUSY);
1804 	}
1805 
1806 	is->is_conn = icl_new_conn(is->is_conf.isc_offload,
1807 	    is->is_conf.isc_iser, "iscsi", &is->is_lock);
1808 	if (is->is_conn == NULL) {
1809 		sx_xunlock(&sc->sc_lock);
1810 		free(is, M_ISCSI);
1811 		return (EINVAL);
1812 	}
1813 	is->is_conn->ic_receive = iscsi_receive_callback;
1814 	is->is_conn->ic_error = iscsi_error_callback;
1815 	is->is_conn->ic_prv0 = is;
1816 	TAILQ_INIT(&is->is_outstanding);
1817 	STAILQ_INIT(&is->is_postponed);
1818 	mtx_init(&is->is_lock, "iscsi_lock", NULL, MTX_DEF);
1819 	cv_init(&is->is_maintenance_cv, "iscsi_mt");
1820 #ifdef ICL_KERNEL_PROXY
1821 	cv_init(&is->is_login_cv, "iscsi_login");
1822 #endif
1823 
1824 	is->is_softc = sc;
1825 	sc->sc_last_session_id++;
1826 	is->is_id = sc->sc_last_session_id;
1827 	is->is_isid[0] = 0x80; /* RFC 3720, 10.12.5: 10b, "Random" ISID. */
1828 	arc4rand(&is->is_isid[1], 5, 0);
1829 	is->is_tsih = 0;
1830 	callout_init(&is->is_callout, 1);
1831 
1832 	error = kthread_add(iscsi_maintenance_thread, is, NULL, NULL, 0, 0, "iscsimt");
1833 	if (error != 0) {
1834 		ISCSI_SESSION_WARN(is, "kthread_add(9) failed with error %d", error);
1835 		sx_xunlock(&sc->sc_lock);
1836 		return (error);
1837 	}
1838 
1839 	callout_reset(&is->is_callout, 1 * hz, iscsi_callout, is);
1840 	TAILQ_INSERT_TAIL(&sc->sc_sessions, is, is_next);
1841 
1842 	ISCSI_SESSION_LOCK(is);
1843 	/*
1844 	 * Don't notify iscsid(8) if the session is disabled and it's not
1845 	 * a discovery session,
1846 	 */
1847 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
1848 		ISCSI_SESSION_UNLOCK(is);
1849 		sx_xunlock(&sc->sc_lock);
1850 		return (0);
1851 	}
1852 
1853 	is->is_waiting_for_iscsid = true;
1854 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
1855 	ISCSI_SESSION_UNLOCK(is);
1856 	cv_signal(&sc->sc_cv);
1857 	sx_xunlock(&sc->sc_lock);
1858 	return (0);
1859 }
1860 
1861 static bool
1862 iscsi_session_conf_matches(unsigned int id1, const struct iscsi_session_conf *c1,
1863     unsigned int id2, const struct iscsi_session_conf *c2)
1864 {
1865 
1866 	if (id2 != 0 && id2 != id1)
1867 		return (false);
1868 	if (c2->isc_target[0] != '\0' &&
1869 	    strcmp(c1->isc_target, c2->isc_target) != 0)
1870 		return (false);
1871 	if (c2->isc_target_addr[0] != '\0' &&
1872 	    strcmp(c1->isc_target_addr, c2->isc_target_addr) != 0)
1873 		return (false);
1874 	return (true);
1875 }
1876 
1877 static int
1878 iscsi_ioctl_session_remove(struct iscsi_softc *sc,
1879     struct iscsi_session_remove *isr)
1880 {
1881 	struct iscsi_session *is, *tmp;
1882 	bool found = false;
1883 
1884 	iscsi_sanitize_session_conf(&isr->isr_conf);
1885 
1886 	sx_xlock(&sc->sc_lock);
1887 	TAILQ_FOREACH_SAFE(is, &sc->sc_sessions, is_next, tmp) {
1888 		ISCSI_SESSION_LOCK(is);
1889 		if (iscsi_session_conf_matches(is->is_id, &is->is_conf,
1890 		    isr->isr_session_id, &isr->isr_conf)) {
1891 			found = true;
1892 			iscsi_session_logout(is);
1893 			iscsi_session_terminate(is);
1894 		}
1895 		ISCSI_SESSION_UNLOCK(is);
1896 	}
1897 	sx_xunlock(&sc->sc_lock);
1898 
1899 	if (!found)
1900 		return (ESRCH);
1901 
1902 	return (0);
1903 }
1904 
1905 static int
1906 iscsi_ioctl_session_list(struct iscsi_softc *sc, struct iscsi_session_list *isl)
1907 {
1908 	int error;
1909 	unsigned int i = 0;
1910 	struct iscsi_session *is;
1911 	struct iscsi_session_state iss;
1912 
1913 	sx_slock(&sc->sc_lock);
1914 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1915 		if (i >= isl->isl_nentries) {
1916 			sx_sunlock(&sc->sc_lock);
1917 			return (EMSGSIZE);
1918 		}
1919 		memset(&iss, 0, sizeof(iss));
1920 		memcpy(&iss.iss_conf, &is->is_conf, sizeof(iss.iss_conf));
1921 		iss.iss_id = is->is_id;
1922 		strlcpy(iss.iss_target_alias, is->is_target_alias, sizeof(iss.iss_target_alias));
1923 		strlcpy(iss.iss_reason, is->is_reason, sizeof(iss.iss_reason));
1924 		strlcpy(iss.iss_offload, is->is_conn->ic_offload, sizeof(iss.iss_offload));
1925 
1926 		if (is->is_conn->ic_header_crc32c)
1927 			iss.iss_header_digest = ISCSI_DIGEST_CRC32C;
1928 		else
1929 			iss.iss_header_digest = ISCSI_DIGEST_NONE;
1930 
1931 		if (is->is_conn->ic_data_crc32c)
1932 			iss.iss_data_digest = ISCSI_DIGEST_CRC32C;
1933 		else
1934 			iss.iss_data_digest = ISCSI_DIGEST_NONE;
1935 
1936 		iss.iss_max_data_segment_length = is->is_max_data_segment_length;
1937 		iss.iss_max_burst_length = is->is_max_burst_length;
1938 		iss.iss_first_burst_length = is->is_first_burst_length;
1939 		iss.iss_immediate_data = is->is_immediate_data;
1940 		iss.iss_connected = is->is_connected;
1941 
1942 		error = copyout(&iss, isl->isl_pstates + i, sizeof(iss));
1943 		if (error != 0) {
1944 			sx_sunlock(&sc->sc_lock);
1945 			return (error);
1946 		}
1947 		i++;
1948 	}
1949 	sx_sunlock(&sc->sc_lock);
1950 
1951 	isl->isl_nentries = i;
1952 
1953 	return (0);
1954 }
1955 
1956 static int
1957 iscsi_ioctl_session_modify(struct iscsi_softc *sc,
1958     struct iscsi_session_modify *ism)
1959 {
1960 	struct iscsi_session *is;
1961 
1962 	iscsi_sanitize_session_conf(&ism->ism_conf);
1963 	if (iscsi_valid_session_conf(&ism->ism_conf) == false)
1964 		return (EINVAL);
1965 
1966 	sx_xlock(&sc->sc_lock);
1967 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1968 		ISCSI_SESSION_LOCK(is);
1969 		if (is->is_id == ism->ism_session_id)
1970 			break;
1971 		ISCSI_SESSION_UNLOCK(is);
1972 	}
1973 	if (is == NULL) {
1974 		sx_xunlock(&sc->sc_lock);
1975 		return (ESRCH);
1976 	}
1977 	sx_xunlock(&sc->sc_lock);
1978 
1979 	memcpy(&is->is_conf, &ism->ism_conf, sizeof(is->is_conf));
1980 	ISCSI_SESSION_UNLOCK(is);
1981 
1982 	iscsi_session_reconnect(is);
1983 
1984 	return (0);
1985 }
1986 
1987 static int
1988 iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
1989     struct thread *td)
1990 {
1991 	struct iscsi_softc *sc;
1992 
1993 	sc = dev->si_drv1;
1994 
1995 	switch (cmd) {
1996 	case ISCSIDWAIT:
1997 		return (iscsi_ioctl_daemon_wait(sc,
1998 		    (struct iscsi_daemon_request *)arg));
1999 	case ISCSIDHANDOFF:
2000 		return (iscsi_ioctl_daemon_handoff(sc,
2001 		    (struct iscsi_daemon_handoff *)arg));
2002 	case ISCSIDFAIL:
2003 		return (iscsi_ioctl_daemon_fail(sc,
2004 		    (struct iscsi_daemon_fail *)arg));
2005 #ifdef ICL_KERNEL_PROXY
2006 	case ISCSIDCONNECT:
2007 		return (iscsi_ioctl_daemon_connect(sc,
2008 		    (struct iscsi_daemon_connect *)arg));
2009 	case ISCSIDSEND:
2010 		return (iscsi_ioctl_daemon_send(sc,
2011 		    (struct iscsi_daemon_send *)arg));
2012 	case ISCSIDRECEIVE:
2013 		return (iscsi_ioctl_daemon_receive(sc,
2014 		    (struct iscsi_daemon_receive *)arg));
2015 #endif /* ICL_KERNEL_PROXY */
2016 	case ISCSISADD:
2017 		return (iscsi_ioctl_session_add(sc,
2018 		    (struct iscsi_session_add *)arg));
2019 	case ISCSISREMOVE:
2020 		return (iscsi_ioctl_session_remove(sc,
2021 		    (struct iscsi_session_remove *)arg));
2022 	case ISCSISLIST:
2023 		return (iscsi_ioctl_session_list(sc,
2024 		    (struct iscsi_session_list *)arg));
2025 	case ISCSISMODIFY:
2026 		return (iscsi_ioctl_session_modify(sc,
2027 		    (struct iscsi_session_modify *)arg));
2028 	default:
2029 		return (EINVAL);
2030 	}
2031 }
2032 
2033 static struct iscsi_outstanding *
2034 iscsi_outstanding_find(struct iscsi_session *is, uint32_t initiator_task_tag)
2035 {
2036 	struct iscsi_outstanding *io;
2037 
2038 	ISCSI_SESSION_LOCK_ASSERT(is);
2039 
2040 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
2041 		if (io->io_initiator_task_tag == initiator_task_tag)
2042 			return (io);
2043 	}
2044 	return (NULL);
2045 }
2046 
2047 static struct iscsi_outstanding *
2048 iscsi_outstanding_find_ccb(struct iscsi_session *is, union ccb *ccb)
2049 {
2050 	struct iscsi_outstanding *io;
2051 
2052 	ISCSI_SESSION_LOCK_ASSERT(is);
2053 
2054 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
2055 		if (io->io_ccb == ccb)
2056 			return (io);
2057 	}
2058 	return (NULL);
2059 }
2060 
2061 static struct iscsi_outstanding *
2062 iscsi_outstanding_add(struct iscsi_session *is, struct icl_pdu *request,
2063     union ccb *ccb, uint32_t *initiator_task_tagp)
2064 {
2065 	struct iscsi_outstanding *io;
2066 	int error;
2067 
2068 	ISCSI_SESSION_LOCK_ASSERT(is);
2069 
2070 	io = uma_zalloc(iscsi_outstanding_zone, M_NOWAIT | M_ZERO);
2071 	if (io == NULL) {
2072 		ISCSI_SESSION_WARN(is, "failed to allocate %zd bytes",
2073 		    sizeof(*io));
2074 		return (NULL);
2075 	}
2076 
2077 	error = icl_conn_task_setup(is->is_conn, request, &ccb->csio,
2078 	    initiator_task_tagp, &io->io_icl_prv);
2079 	if (error != 0) {
2080 		ISCSI_SESSION_WARN(is,
2081 		    "icl_conn_task_setup() failed with error %d", error);
2082 		uma_zfree(iscsi_outstanding_zone, io);
2083 		return (NULL);
2084 	}
2085 
2086 	KASSERT(iscsi_outstanding_find(is, *initiator_task_tagp) == NULL,
2087 	    ("initiator_task_tag 0x%x already added", *initiator_task_tagp));
2088 
2089 	io->io_initiator_task_tag = *initiator_task_tagp;
2090 	io->io_ccb = ccb;
2091 	TAILQ_INSERT_TAIL(&is->is_outstanding, io, io_next);
2092 	return (io);
2093 }
2094 
2095 static void
2096 iscsi_outstanding_remove(struct iscsi_session *is, struct iscsi_outstanding *io)
2097 {
2098 
2099 	ISCSI_SESSION_LOCK_ASSERT(is);
2100 
2101 	icl_conn_task_done(is->is_conn, io->io_icl_prv);
2102 	TAILQ_REMOVE(&is->is_outstanding, io, io_next);
2103 	uma_zfree(iscsi_outstanding_zone, io);
2104 }
2105 
2106 static void
2107 iscsi_action_abort(struct iscsi_session *is, union ccb *ccb)
2108 {
2109 	struct icl_pdu *request;
2110 	struct iscsi_bhs_task_management_request *bhstmr;
2111 	struct ccb_abort *cab = &ccb->cab;
2112 	struct iscsi_outstanding *io, *aio;
2113 	uint32_t initiator_task_tag;
2114 
2115 	ISCSI_SESSION_LOCK_ASSERT(is);
2116 
2117 #if 0
2118 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2119 #else
2120 	if (is->is_login_phase) {
2121 		ccb->ccb_h.status = CAM_REQ_ABORTED;
2122 		xpt_done(ccb);
2123 		return;
2124 	}
2125 #endif
2126 
2127 	aio = iscsi_outstanding_find_ccb(is, cab->abort_ccb);
2128 	if (aio == NULL) {
2129 		ccb->ccb_h.status = CAM_REQ_CMP;
2130 		xpt_done(ccb);
2131 		return;
2132 	}
2133 
2134 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2135 	if (request == NULL) {
2136 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2137 		xpt_done(ccb);
2138 		return;
2139 	}
2140 
2141 	initiator_task_tag = is->is_initiator_task_tag++;
2142 
2143 	io = iscsi_outstanding_add(is, request, NULL, &initiator_task_tag);
2144 	if (io == NULL) {
2145 		icl_pdu_free(request);
2146 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2147 		xpt_done(ccb);
2148 		return;
2149 	}
2150 	io->io_datasn = aio->io_initiator_task_tag;
2151 
2152 	bhstmr = (struct iscsi_bhs_task_management_request *)request->ip_bhs;
2153 	bhstmr->bhstmr_opcode = ISCSI_BHS_OPCODE_TASK_REQUEST;
2154 	bhstmr->bhstmr_function = 0x80 | BHSTMR_FUNCTION_ABORT_TASK;
2155 	bhstmr->bhstmr_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2156 	bhstmr->bhstmr_initiator_task_tag = initiator_task_tag;
2157 	bhstmr->bhstmr_referenced_task_tag = aio->io_initiator_task_tag;
2158 
2159 	iscsi_pdu_queue_locked(request);
2160 }
2161 
2162 static void
2163 iscsi_action_scsiio(struct iscsi_session *is, union ccb *ccb)
2164 {
2165 	struct icl_pdu *request;
2166 	struct iscsi_bhs_scsi_command *bhssc;
2167 	struct ccb_scsiio *csio;
2168 	struct iscsi_outstanding *io;
2169 	size_t len;
2170 	uint32_t initiator_task_tag;
2171 	int error;
2172 
2173 	ISCSI_SESSION_LOCK_ASSERT(is);
2174 
2175 #if 0
2176 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2177 #else
2178 	if (is->is_login_phase) {
2179 		ISCSI_SESSION_DEBUG(is, "called during login phase");
2180 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2181 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2182 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2183 		}
2184 		ccb->ccb_h.status = CAM_REQ_ABORTED | CAM_DEV_QFRZN;
2185 		xpt_done(ccb);
2186 		return;
2187 	}
2188 #endif
2189 
2190 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2191 	if (request == NULL) {
2192 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2193 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2194 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2195 		}
2196 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2197 		xpt_done(ccb);
2198 		return;
2199 	}
2200 
2201 	initiator_task_tag = is->is_initiator_task_tag++;
2202 	io = iscsi_outstanding_add(is, request, ccb, &initiator_task_tag);
2203 	if (io == NULL) {
2204 		icl_pdu_free(request);
2205 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2206 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2207 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2208 		}
2209 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2210 		xpt_done(ccb);
2211 		return;
2212 	}
2213 
2214 	csio = &ccb->csio;
2215 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
2216 	bhssc->bhssc_opcode = ISCSI_BHS_OPCODE_SCSI_COMMAND;
2217 	bhssc->bhssc_flags |= BHSSC_FLAGS_F;
2218 	switch (csio->ccb_h.flags & CAM_DIR_MASK) {
2219 	case CAM_DIR_IN:
2220 		bhssc->bhssc_flags |= BHSSC_FLAGS_R;
2221 		break;
2222 	case CAM_DIR_OUT:
2223 		bhssc->bhssc_flags |= BHSSC_FLAGS_W;
2224 		break;
2225 	}
2226 
2227 	if ((ccb->ccb_h.flags & CAM_TAG_ACTION_VALID) != 0) {
2228 		switch (csio->tag_action) {
2229 		case MSG_HEAD_OF_Q_TAG:
2230 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_HOQ;
2231 			break;
2232 		case MSG_ORDERED_Q_TAG:
2233 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ORDERED;
2234 			break;
2235 		case MSG_ACA_TASK:
2236 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ACA;
2237 			break;
2238 		case MSG_SIMPLE_Q_TAG:
2239 		default:
2240 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_SIMPLE;
2241 			break;
2242 		}
2243 	} else
2244 		bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_UNTAGGED;
2245 
2246 	bhssc->bhssc_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2247 	bhssc->bhssc_initiator_task_tag = initiator_task_tag;
2248 	bhssc->bhssc_expected_data_transfer_length = htonl(csio->dxfer_len);
2249 	KASSERT(csio->cdb_len <= sizeof(bhssc->bhssc_cdb),
2250 	    ("unsupported CDB size %zd", (size_t)csio->cdb_len));
2251 
2252 	if (csio->ccb_h.flags & CAM_CDB_POINTER)
2253 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_ptr, csio->cdb_len);
2254 	else
2255 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_bytes, csio->cdb_len);
2256 
2257 	if (is->is_immediate_data &&
2258 	    (csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT) {
2259 		len = csio->dxfer_len;
2260 		//ISCSI_SESSION_DEBUG(is, "adding %zd of immediate data", len);
2261 		if (len > is->is_first_burst_length) {
2262 			ISCSI_SESSION_DEBUG(is, "len %zd -> %zd", len, is->is_first_burst_length);
2263 			len = is->is_first_burst_length;
2264 		}
2265 		if (len > is->is_max_data_segment_length) {
2266 			ISCSI_SESSION_DEBUG(is, "len %zd -> %zd", len, is->is_max_data_segment_length);
2267 			len = is->is_max_data_segment_length;
2268 		}
2269 
2270 		error = icl_pdu_append_data(request, csio->data_ptr, len, M_NOWAIT);
2271 		if (error != 0) {
2272 			iscsi_outstanding_remove(is, io);
2273 			icl_pdu_free(request);
2274 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2275 				xpt_freeze_devq(ccb->ccb_h.path, 1);
2276 				ISCSI_SESSION_DEBUG(is, "freezing devq");
2277 			}
2278 			ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2279 			xpt_done(ccb);
2280 			return;
2281 		}
2282 	}
2283 	iscsi_pdu_queue_locked(request);
2284 }
2285 
2286 static void
2287 iscsi_action(struct cam_sim *sim, union ccb *ccb)
2288 {
2289 	struct iscsi_session *is;
2290 
2291 	is = cam_sim_softc(sim);
2292 
2293 	ISCSI_SESSION_LOCK_ASSERT(is);
2294 
2295 	if (is->is_terminating ||
2296 	    (is->is_connected == false && fail_on_disconnection)) {
2297 		ccb->ccb_h.status = CAM_DEV_NOT_THERE;
2298 		xpt_done(ccb);
2299 		return;
2300 	}
2301 
2302 	switch (ccb->ccb_h.func_code) {
2303 	case XPT_PATH_INQ:
2304 	{
2305 		struct ccb_pathinq *cpi = &ccb->cpi;
2306 
2307 		cpi->version_num = 1;
2308 		cpi->hba_inquiry = PI_TAG_ABLE;
2309 		cpi->target_sprt = 0;
2310 		cpi->hba_misc = PIM_EXTLUNS;
2311 		/*
2312 		 * XXX: It shouldn't ever be NULL; this could be turned
2313 		 *      into a KASSERT eventually.
2314 		 */
2315 		if (is->is_conn == NULL)
2316 			ISCSI_WARN("NULL conn");
2317 		else if (is->is_conn->ic_unmapped)
2318 			cpi->hba_misc |= PIM_UNMAPPED;
2319 		cpi->hba_eng_cnt = 0;
2320 		cpi->max_target = 0;
2321 		/*
2322 		 * Note that the variable below is only relevant for targets
2323 		 * that don't claim compliance with anything above SPC2, which
2324 		 * means they don't support REPORT_LUNS.
2325 		 */
2326 		cpi->max_lun = 255;
2327 		cpi->initiator_id = ~0;
2328 		strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
2329 		strlcpy(cpi->hba_vid, "iSCSI", HBA_IDLEN);
2330 		strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
2331 		cpi->unit_number = cam_sim_unit(sim);
2332 		cpi->bus_id = cam_sim_bus(sim);
2333 		cpi->base_transfer_speed = 150000; /* XXX */
2334 		cpi->transport = XPORT_ISCSI;
2335 		cpi->transport_version = 0;
2336 		cpi->protocol = PROTO_SCSI;
2337 		cpi->protocol_version = SCSI_REV_SPC3;
2338 		cpi->maxio = MAXPHYS;
2339 		cpi->ccb_h.status = CAM_REQ_CMP;
2340 		break;
2341 	}
2342 	case XPT_GET_TRAN_SETTINGS:
2343 	{
2344 		struct ccb_trans_settings	*cts;
2345 		struct ccb_trans_settings_scsi	*scsi;
2346 
2347 		cts = &ccb->cts;
2348 		scsi = &cts->proto_specific.scsi;
2349 
2350 		cts->protocol = PROTO_SCSI;
2351 		cts->protocol_version = SCSI_REV_SPC3;
2352 		cts->transport = XPORT_ISCSI;
2353 		cts->transport_version = 0;
2354 		scsi->valid = CTS_SCSI_VALID_TQ;
2355 		scsi->flags = CTS_SCSI_FLAGS_TAG_ENB;
2356 		cts->ccb_h.status = CAM_REQ_CMP;
2357 		break;
2358 	}
2359 	case XPT_CALC_GEOMETRY:
2360 		cam_calc_geometry(&ccb->ccg, /*extended*/1);
2361 		ccb->ccb_h.status = CAM_REQ_CMP;
2362 		break;
2363 #if 0
2364 	/*
2365 	 * XXX: What's the point?
2366 	 */
2367 	case XPT_RESET_BUS:
2368 	case XPT_TERM_IO:
2369 		ISCSI_SESSION_DEBUG(is, "faking success for reset, abort, or term_io");
2370 		ccb->ccb_h.status = CAM_REQ_CMP;
2371 		break;
2372 #endif
2373 	case XPT_ABORT:
2374 		iscsi_action_abort(is, ccb);
2375 		return;
2376 	case XPT_SCSI_IO:
2377 		iscsi_action_scsiio(is, ccb);
2378 		return;
2379 	default:
2380 #if 0
2381 		ISCSI_SESSION_DEBUG(is, "got unsupported code 0x%x", ccb->ccb_h.func_code);
2382 #endif
2383 		ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
2384 		break;
2385 	}
2386 	xpt_done(ccb);
2387 }
2388 
2389 static void
2390 iscsi_poll(struct cam_sim *sim)
2391 {
2392 
2393 	KASSERT(0, ("%s: you're not supposed to be here", __func__));
2394 }
2395 
2396 static void
2397 iscsi_terminate_sessions(struct iscsi_softc *sc)
2398 {
2399 	struct iscsi_session *is;
2400 
2401 	sx_slock(&sc->sc_lock);
2402 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next)
2403 		iscsi_session_terminate(is);
2404 	while(!TAILQ_EMPTY(&sc->sc_sessions)) {
2405 		ISCSI_DEBUG("waiting for sessions to terminate");
2406 		cv_wait(&sc->sc_cv, &sc->sc_lock);
2407 	}
2408 	ISCSI_DEBUG("all sessions terminated");
2409 	sx_sunlock(&sc->sc_lock);
2410 }
2411 
2412 static void
2413 iscsi_shutdown_pre(struct iscsi_softc *sc)
2414 {
2415 	struct iscsi_session *is;
2416 
2417 	if (!fail_on_shutdown)
2418 		return;
2419 
2420 	/*
2421 	 * If we have any sessions waiting for reconnection, request
2422 	 * maintenance thread to fail them immediately instead of waiting
2423 	 * for reconnect timeout.
2424 	 *
2425 	 * This prevents LUNs with mounted filesystems that are supported
2426 	 * by disconnected iSCSI sessions from hanging, however it will
2427 	 * fail all queued BIOs.
2428 	 */
2429 	ISCSI_DEBUG("forcing failing all disconnected sessions due to shutdown");
2430 
2431 	fail_on_disconnection = 1;
2432 
2433 	sx_slock(&sc->sc_lock);
2434 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
2435 		ISCSI_SESSION_LOCK(is);
2436 		if (!is->is_connected) {
2437 			ISCSI_SESSION_DEBUG(is, "force failing disconnected session early");
2438 			iscsi_session_reconnect(is);
2439 		}
2440 		ISCSI_SESSION_UNLOCK(is);
2441 	}
2442 	sx_sunlock(&sc->sc_lock);
2443 }
2444 
2445 static void
2446 iscsi_shutdown_post(struct iscsi_softc *sc)
2447 {
2448 
2449 	ISCSI_DEBUG("removing all sessions due to shutdown");
2450 	iscsi_terminate_sessions(sc);
2451 }
2452 
2453 static int
2454 iscsi_load(void)
2455 {
2456 	int error;
2457 
2458 	sc = malloc(sizeof(*sc), M_ISCSI, M_ZERO | M_WAITOK);
2459 	sx_init(&sc->sc_lock, "iscsi");
2460 	TAILQ_INIT(&sc->sc_sessions);
2461 	cv_init(&sc->sc_cv, "iscsi_cv");
2462 
2463 	iscsi_outstanding_zone = uma_zcreate("iscsi_outstanding",
2464 	    sizeof(struct iscsi_outstanding), NULL, NULL, NULL, NULL,
2465 	    UMA_ALIGN_PTR, 0);
2466 
2467 	error = make_dev_p(MAKEDEV_CHECKNAME, &sc->sc_cdev, &iscsi_cdevsw,
2468 	    NULL, UID_ROOT, GID_WHEEL, 0600, "iscsi");
2469 	if (error != 0) {
2470 		ISCSI_WARN("failed to create device node, error %d", error);
2471 		return (error);
2472 	}
2473 	sc->sc_cdev->si_drv1 = sc;
2474 
2475 	sc->sc_shutdown_pre_eh = EVENTHANDLER_REGISTER(shutdown_pre_sync,
2476 	    iscsi_shutdown_pre, sc, SHUTDOWN_PRI_FIRST);
2477 	/*
2478 	 * shutdown_post_sync needs to run after filesystem shutdown and before
2479 	 * CAM shutdown - otherwise when rebooting with an iSCSI session that is
2480 	 * disconnected but has outstanding requests, dashutdown() will hang on
2481 	 * cam_periph_runccb().
2482 	 */
2483 	sc->sc_shutdown_post_eh = EVENTHANDLER_REGISTER(shutdown_post_sync,
2484 	    iscsi_shutdown_post, sc, SHUTDOWN_PRI_DEFAULT - 1);
2485 
2486 	return (0);
2487 }
2488 
2489 static int
2490 iscsi_unload(void)
2491 {
2492 
2493 	if (sc->sc_cdev != NULL) {
2494 		ISCSI_DEBUG("removing device node");
2495 		destroy_dev(sc->sc_cdev);
2496 		ISCSI_DEBUG("device node removed");
2497 	}
2498 
2499 	if (sc->sc_shutdown_pre_eh != NULL)
2500 		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, sc->sc_shutdown_pre_eh);
2501 	if (sc->sc_shutdown_post_eh != NULL)
2502 		EVENTHANDLER_DEREGISTER(shutdown_post_sync, sc->sc_shutdown_post_eh);
2503 
2504 	iscsi_terminate_sessions(sc);
2505 
2506 	uma_zdestroy(iscsi_outstanding_zone);
2507 	sx_destroy(&sc->sc_lock);
2508 	cv_destroy(&sc->sc_cv);
2509 	free(sc, M_ISCSI);
2510 	return (0);
2511 }
2512 
2513 static int
2514 iscsi_quiesce(void)
2515 {
2516 	sx_slock(&sc->sc_lock);
2517 	if (!TAILQ_EMPTY(&sc->sc_sessions)) {
2518 		sx_sunlock(&sc->sc_lock);
2519 		return (EBUSY);
2520 	}
2521 	sx_sunlock(&sc->sc_lock);
2522 	return (0);
2523 }
2524 
2525 static int
2526 iscsi_modevent(module_t mod, int what, void *arg)
2527 {
2528 	int error;
2529 
2530 	switch (what) {
2531 	case MOD_LOAD:
2532 		error = iscsi_load();
2533 		break;
2534 	case MOD_UNLOAD:
2535 		error = iscsi_unload();
2536 		break;
2537 	case MOD_QUIESCE:
2538 		error = iscsi_quiesce();
2539 		break;
2540 	default:
2541 		error = EINVAL;
2542 		break;
2543 	}
2544 	return (error);
2545 }
2546 
2547 moduledata_t iscsi_data = {
2548 	"iscsi",
2549 	iscsi_modevent,
2550 	0
2551 };
2552 
2553 DECLARE_MODULE(iscsi, iscsi_data, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
2554 MODULE_DEPEND(iscsi, cam, 1, 1, 1);
2555 MODULE_DEPEND(iscsi, icl, 1, 1, 1);
2556