xref: /freebsd/sys/dev/iscsi/iscsi.c (revision 7be9a3b45356747f9fcb6d69a722c1c95f8060bf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2012 The FreeBSD Foundation
5  *
6  * This software was developed by Edward Tomasz Napierala under sponsorship
7  * from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/condvar.h>
37 #include <sys/conf.h>
38 #include <sys/endian.h>
39 #include <sys/eventhandler.h>
40 #include <sys/file.h>
41 #include <sys/kernel.h>
42 #include <sys/kthread.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mutex.h>
46 #include <sys/module.h>
47 #include <sys/socket.h>
48 #include <sys/sysctl.h>
49 #include <sys/systm.h>
50 #include <sys/sx.h>
51 #include <vm/uma.h>
52 
53 #include <cam/cam.h>
54 #include <cam/cam_ccb.h>
55 #include <cam/cam_xpt.h>
56 #include <cam/cam_debug.h>
57 #include <cam/cam_sim.h>
58 #include <cam/cam_xpt_sim.h>
59 #include <cam/cam_xpt_periph.h>
60 #include <cam/cam_periph.h>
61 #include <cam/scsi/scsi_all.h>
62 #include <cam/scsi/scsi_message.h>
63 
64 #include <dev/iscsi/icl.h>
65 #include <dev/iscsi/icl_wrappers.h>
66 #include <dev/iscsi/iscsi_ioctl.h>
67 #include <dev/iscsi/iscsi_proto.h>
68 #include <dev/iscsi/iscsi.h>
69 
70 #ifdef ICL_KERNEL_PROXY
71 #include <sys/socketvar.h>
72 #endif
73 
74 #ifdef ICL_KERNEL_PROXY
75 FEATURE(iscsi_kernel_proxy, "iSCSI initiator built with ICL_KERNEL_PROXY");
76 #endif
77 
78 /*
79  * XXX: This is global so the iscsi_unload() can access it.
80  * 	Think about how to do this properly.
81  */
82 static struct iscsi_softc	*sc;
83 
84 SYSCTL_NODE(_kern, OID_AUTO, iscsi, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
85     "iSCSI initiator");
86 static int debug = 1;
87 SYSCTL_INT(_kern_iscsi, OID_AUTO, debug, CTLFLAG_RWTUN,
88     &debug, 0, "Enable debug messages");
89 static int ping_timeout = 5;
90 SYSCTL_INT(_kern_iscsi, OID_AUTO, ping_timeout, CTLFLAG_RWTUN, &ping_timeout,
91     0, "Timeout for ping (NOP-Out) requests, in seconds");
92 static int iscsid_timeout = 60;
93 SYSCTL_INT(_kern_iscsi, OID_AUTO, iscsid_timeout, CTLFLAG_RWTUN, &iscsid_timeout,
94     0, "Time to wait for iscsid(8) to handle reconnection, in seconds");
95 static int login_timeout = 60;
96 SYSCTL_INT(_kern_iscsi, OID_AUTO, login_timeout, CTLFLAG_RWTUN, &login_timeout,
97     0, "Time to wait for iscsid(8) to finish Login Phase, in seconds");
98 static int maxtags = 255;
99 SYSCTL_INT(_kern_iscsi, OID_AUTO, maxtags, CTLFLAG_RWTUN, &maxtags,
100     0, "Max number of IO requests queued");
101 static int fail_on_disconnection = 0;
102 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_disconnection, CTLFLAG_RWTUN,
103     &fail_on_disconnection, 0, "Destroy CAM SIM on connection failure");
104 static int fail_on_shutdown = 1;
105 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_shutdown, CTLFLAG_RWTUN,
106     &fail_on_shutdown, 0, "Fail disconnected sessions on shutdown");
107 
108 static MALLOC_DEFINE(M_ISCSI, "iSCSI", "iSCSI initiator");
109 static uma_zone_t iscsi_outstanding_zone;
110 
111 #define	CONN_SESSION(X)	((struct iscsi_session *)X->ic_prv0)
112 #define	PDU_SESSION(X)	(CONN_SESSION(X->ip_conn))
113 
114 #define	ISCSI_DEBUG(X, ...)						\
115 	do {								\
116 		if (debug > 1) 						\
117 			printf("%s: " X "\n", __func__, ## __VA_ARGS__);\
118 	} while (0)
119 
120 #define	ISCSI_WARN(X, ...)						\
121 	do {								\
122 		if (debug > 0) {					\
123 			printf("WARNING: %s: " X "\n",			\
124 			    __func__, ## __VA_ARGS__);			\
125 		}							\
126 	} while (0)
127 
128 #define	ISCSI_SESSION_DEBUG(S, X, ...)					\
129 	do {								\
130 		if (debug > 1) {					\
131 			printf("%s: %s (%s): " X "\n",			\
132 			    __func__, S->is_conf.isc_target_addr,	\
133 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
134 		}							\
135 	} while (0)
136 
137 #define	ISCSI_SESSION_WARN(S, X, ...)					\
138 	do {								\
139 		if (debug > 0) {					\
140 			printf("WARNING: %s (%s): " X "\n",		\
141 			    S->is_conf.isc_target_addr,			\
142 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
143 		}							\
144 	} while (0)
145 
146 #define ISCSI_SESSION_LOCK(X)		mtx_lock(&X->is_lock)
147 #define ISCSI_SESSION_UNLOCK(X)		mtx_unlock(&X->is_lock)
148 #define ISCSI_SESSION_LOCK_ASSERT(X)	mtx_assert(&X->is_lock, MA_OWNED)
149 #define ISCSI_SESSION_LOCK_ASSERT_NOT(X) mtx_assert(&X->is_lock, MA_NOTOWNED)
150 
151 static int	iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg,
152 		    int mode, struct thread *td);
153 
154 static struct cdevsw iscsi_cdevsw = {
155      .d_version = D_VERSION,
156      .d_ioctl   = iscsi_ioctl,
157      .d_name    = "iscsi",
158 };
159 
160 static void	iscsi_pdu_queue_locked(struct icl_pdu *request);
161 static void	iscsi_pdu_queue(struct icl_pdu *request);
162 static void	iscsi_pdu_update_statsn(const struct icl_pdu *response);
163 static void	iscsi_pdu_handle_nop_in(struct icl_pdu *response);
164 static void	iscsi_pdu_handle_scsi_response(struct icl_pdu *response);
165 static void	iscsi_pdu_handle_task_response(struct icl_pdu *response);
166 static void	iscsi_pdu_handle_data_in(struct icl_pdu *response);
167 static void	iscsi_pdu_handle_logout_response(struct icl_pdu *response);
168 static void	iscsi_pdu_handle_r2t(struct icl_pdu *response);
169 static void	iscsi_pdu_handle_async_message(struct icl_pdu *response);
170 static void	iscsi_pdu_handle_reject(struct icl_pdu *response);
171 static void	iscsi_session_reconnect(struct iscsi_session *is);
172 static void	iscsi_session_terminate(struct iscsi_session *is);
173 static void	iscsi_action(struct cam_sim *sim, union ccb *ccb);
174 static struct iscsi_outstanding	*iscsi_outstanding_find(struct iscsi_session *is,
175 		    uint32_t initiator_task_tag);
176 static struct iscsi_outstanding	*iscsi_outstanding_add(struct iscsi_session *is,
177 		    struct icl_pdu *request, union ccb *ccb,
178 		    uint32_t *initiator_task_tagp);
179 static void	iscsi_outstanding_remove(struct iscsi_session *is,
180 		    struct iscsi_outstanding *io);
181 
182 static bool
183 iscsi_pdu_prepare(struct icl_pdu *request)
184 {
185 	struct iscsi_session *is;
186 	struct iscsi_bhs_scsi_command *bhssc;
187 
188 	is = PDU_SESSION(request);
189 
190 	ISCSI_SESSION_LOCK_ASSERT(is);
191 
192 	/*
193 	 * We're only using fields common for all the request
194 	 * (initiator -> target) PDUs.
195 	 */
196 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
197 
198 	/*
199 	 * Data-Out PDU does not contain CmdSN.
200 	 */
201 	if (bhssc->bhssc_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_OUT) {
202 		if (ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn) &&
203 		    (bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0) {
204 			/*
205 			 * Current MaxCmdSN prevents us from sending any more
206 			 * SCSI Command PDUs to the target; postpone the PDU.
207 			 * It will get resent by either iscsi_pdu_queue(),
208 			 * or by maintenance thread.
209 			 */
210 #if 0
211 			ISCSI_SESSION_DEBUG(is, "postponing send, CmdSN %u, "
212 			    "ExpCmdSN %u, MaxCmdSN %u, opcode 0x%x",
213 			    is->is_cmdsn, is->is_expcmdsn, is->is_maxcmdsn,
214 			    bhssc->bhssc_opcode);
215 #endif
216 			return (true);
217 		}
218 		bhssc->bhssc_cmdsn = htonl(is->is_cmdsn);
219 		if ((bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0)
220 			is->is_cmdsn++;
221 	}
222 	bhssc->bhssc_expstatsn = htonl(is->is_statsn + 1);
223 
224 	return (false);
225 }
226 
227 static void
228 iscsi_session_send_postponed(struct iscsi_session *is)
229 {
230 	struct icl_pdu *request;
231 	bool postpone;
232 
233 	ISCSI_SESSION_LOCK_ASSERT(is);
234 
235 	if (STAILQ_EMPTY(&is->is_postponed))
236 		return;
237 	while ((request = STAILQ_FIRST(&is->is_postponed)) != NULL) {
238 		postpone = iscsi_pdu_prepare(request);
239 		if (postpone)
240 			return;
241 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
242 		icl_pdu_queue(request);
243 	}
244 	xpt_release_simq(is->is_sim, 1);
245 }
246 
247 static void
248 iscsi_pdu_queue_locked(struct icl_pdu *request)
249 {
250 	struct iscsi_session *is;
251 	bool postpone;
252 
253 	is = PDU_SESSION(request);
254 	ISCSI_SESSION_LOCK_ASSERT(is);
255 	iscsi_session_send_postponed(is);
256 	postpone = iscsi_pdu_prepare(request);
257 	if (postpone) {
258 		if (STAILQ_EMPTY(&is->is_postponed))
259 			xpt_freeze_simq(is->is_sim, 1);
260 		STAILQ_INSERT_TAIL(&is->is_postponed, request, ip_next);
261 		return;
262 	}
263 	icl_pdu_queue(request);
264 }
265 
266 static void
267 iscsi_pdu_queue(struct icl_pdu *request)
268 {
269 	struct iscsi_session *is;
270 
271 	is = PDU_SESSION(request);
272 	ISCSI_SESSION_LOCK(is);
273 	iscsi_pdu_queue_locked(request);
274 	ISCSI_SESSION_UNLOCK(is);
275 }
276 
277 static void
278 iscsi_session_logout(struct iscsi_session *is)
279 {
280 	struct icl_pdu *request;
281 	struct iscsi_bhs_logout_request *bhslr;
282 
283 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
284 	if (request == NULL)
285 		return;
286 
287 	bhslr = (struct iscsi_bhs_logout_request *)request->ip_bhs;
288 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST;
289 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
290 	iscsi_pdu_queue_locked(request);
291 }
292 
293 static void
294 iscsi_session_terminate_task(struct iscsi_session *is,
295     struct iscsi_outstanding *io, cam_status status)
296 {
297 
298 	ISCSI_SESSION_LOCK_ASSERT(is);
299 
300 	if (io->io_ccb != NULL) {
301 		io->io_ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
302 		io->io_ccb->ccb_h.status |= status;
303 		if ((io->io_ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
304 			io->io_ccb->ccb_h.status |= CAM_DEV_QFRZN;
305 			xpt_freeze_devq(io->io_ccb->ccb_h.path, 1);
306 			ISCSI_SESSION_DEBUG(is, "freezing devq");
307 		}
308 		xpt_done(io->io_ccb);
309 	}
310 	iscsi_outstanding_remove(is, io);
311 }
312 
313 static void
314 iscsi_session_terminate_tasks(struct iscsi_session *is, cam_status status)
315 {
316 	struct iscsi_outstanding *io, *tmp;
317 
318 	ISCSI_SESSION_LOCK_ASSERT(is);
319 
320 	TAILQ_FOREACH_SAFE(io, &is->is_outstanding, io_next, tmp) {
321 		iscsi_session_terminate_task(is, io, status);
322 	}
323 }
324 
325 static void
326 iscsi_session_cleanup(struct iscsi_session *is, bool destroy_sim)
327 {
328 	struct icl_pdu *pdu;
329 
330 	ISCSI_SESSION_LOCK_ASSERT(is);
331 
332 	/*
333 	 * Don't queue any new PDUs.
334 	 */
335 	if (is->is_sim != NULL && is->is_simq_frozen == false) {
336 		ISCSI_SESSION_DEBUG(is, "freezing");
337 		xpt_freeze_simq(is->is_sim, 1);
338 		is->is_simq_frozen = true;
339 	}
340 
341 	/*
342 	 * Remove postponed PDUs.
343 	 */
344 	if (!STAILQ_EMPTY(&is->is_postponed))
345 		xpt_release_simq(is->is_sim, 1);
346 	while ((pdu = STAILQ_FIRST(&is->is_postponed)) != NULL) {
347 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
348 		icl_pdu_free(pdu);
349 	}
350 
351 	if (destroy_sim == false) {
352 		/*
353 		 * Terminate SCSI tasks, asking CAM to requeue them.
354 		 */
355 		iscsi_session_terminate_tasks(is, CAM_REQUEUE_REQ);
356 		return;
357 	}
358 
359 	iscsi_session_terminate_tasks(is, CAM_DEV_NOT_THERE);
360 
361 	if (is->is_sim == NULL)
362 		return;
363 
364 	ISCSI_SESSION_DEBUG(is, "deregistering SIM");
365 	xpt_async(AC_LOST_DEVICE, is->is_path, NULL);
366 
367 	if (is->is_simq_frozen) {
368 		is->is_simq_frozen = false;
369 		xpt_release_simq(is->is_sim, 1);
370 	}
371 
372 	xpt_free_path(is->is_path);
373 	is->is_path = NULL;
374 	xpt_bus_deregister(cam_sim_path(is->is_sim));
375 	cam_sim_free(is->is_sim, TRUE /*free_devq*/);
376 	is->is_sim = NULL;
377 	is->is_devq = NULL;
378 }
379 
380 static void
381 iscsi_maintenance_thread_reconnect(struct iscsi_session *is)
382 {
383 
384 	icl_conn_close(is->is_conn);
385 
386 	ISCSI_SESSION_LOCK(is);
387 
388 	is->is_connected = false;
389 	is->is_reconnecting = false;
390 	is->is_login_phase = false;
391 
392 #ifdef ICL_KERNEL_PROXY
393 	if (is->is_login_pdu != NULL) {
394 		icl_pdu_free(is->is_login_pdu);
395 		is->is_login_pdu = NULL;
396 	}
397 	cv_signal(&is->is_login_cv);
398 #endif
399 
400 	if (fail_on_disconnection) {
401 		ISCSI_SESSION_DEBUG(is, "connection failed, destroying devices");
402 		iscsi_session_cleanup(is, true);
403 	} else {
404 		iscsi_session_cleanup(is, false);
405 	}
406 
407 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
408 	    ("destroying session with active tasks"));
409 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
410 	    ("destroying session with postponed PDUs"));
411 
412 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
413 		ISCSI_SESSION_UNLOCK(is);
414 		return;
415 	}
416 
417 	/*
418 	 * Request immediate reconnection from iscsid(8).
419 	 */
420 	//ISCSI_SESSION_DEBUG(is, "waking up iscsid(8)");
421 	is->is_waiting_for_iscsid = true;
422 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
423 	is->is_timeout = 0;
424 	ISCSI_SESSION_UNLOCK(is);
425 	cv_signal(&is->is_softc->sc_cv);
426 }
427 
428 static void
429 iscsi_maintenance_thread_terminate(struct iscsi_session *is)
430 {
431 	struct iscsi_softc *sc;
432 
433 	sc = is->is_softc;
434 	sx_xlock(&sc->sc_lock);
435 	TAILQ_REMOVE(&sc->sc_sessions, is, is_next);
436 	sx_xunlock(&sc->sc_lock);
437 
438 	icl_conn_close(is->is_conn);
439 	callout_drain(&is->is_callout);
440 
441 	ISCSI_SESSION_LOCK(is);
442 
443 	KASSERT(is->is_terminating, ("is_terminating == false"));
444 
445 #ifdef ICL_KERNEL_PROXY
446 	if (is->is_login_pdu != NULL) {
447 		icl_pdu_free(is->is_login_pdu);
448 		is->is_login_pdu = NULL;
449 	}
450 	cv_signal(&is->is_login_cv);
451 #endif
452 
453 	iscsi_session_cleanup(is, true);
454 
455 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
456 	    ("destroying session with active tasks"));
457 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
458 	    ("destroying session with postponed PDUs"));
459 
460 	ISCSI_SESSION_UNLOCK(is);
461 
462 	icl_conn_free(is->is_conn);
463 	mtx_destroy(&is->is_lock);
464 	cv_destroy(&is->is_maintenance_cv);
465 #ifdef ICL_KERNEL_PROXY
466 	cv_destroy(&is->is_login_cv);
467 #endif
468 
469 	ISCSI_SESSION_DEBUG(is, "terminated");
470 	free(is, M_ISCSI);
471 
472 	/*
473 	 * The iscsi_unload() routine might be waiting.
474 	 */
475 	cv_signal(&sc->sc_cv);
476 }
477 
478 static void
479 iscsi_maintenance_thread(void *arg)
480 {
481 	struct iscsi_session *is = arg;
482 
483 	ISCSI_SESSION_LOCK(is);
484 	for (;;) {
485 		if (is->is_reconnecting == false &&
486 		    is->is_terminating == false &&
487 		    (STAILQ_EMPTY(&is->is_postponed) ||
488 		     ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn)))
489 			cv_wait(&is->is_maintenance_cv, &is->is_lock);
490 
491 		/* Terminate supersedes reconnect. */
492 		if (is->is_terminating) {
493 			ISCSI_SESSION_UNLOCK(is);
494 			iscsi_maintenance_thread_terminate(is);
495 			kthread_exit();
496 			return;
497 		}
498 
499 		if (is->is_reconnecting) {
500 			ISCSI_SESSION_UNLOCK(is);
501 			iscsi_maintenance_thread_reconnect(is);
502 			ISCSI_SESSION_LOCK(is);
503 			continue;
504 		}
505 
506 		iscsi_session_send_postponed(is);
507 	}
508 	ISCSI_SESSION_UNLOCK(is);
509 }
510 
511 static void
512 iscsi_session_reconnect(struct iscsi_session *is)
513 {
514 
515 	/*
516 	 * XXX: We can't use locking here, because
517 	 * 	it's being called from various contexts.
518 	 * 	Hope it doesn't break anything.
519 	 */
520 	if (is->is_reconnecting)
521 		return;
522 
523 	is->is_reconnecting = true;
524 	cv_signal(&is->is_maintenance_cv);
525 }
526 
527 static void
528 iscsi_session_terminate(struct iscsi_session *is)
529 {
530 
531 	if (is->is_terminating)
532 		return;
533 
534 	is->is_terminating = true;
535 
536 #if 0
537 	iscsi_session_logout(is);
538 #endif
539 	cv_signal(&is->is_maintenance_cv);
540 }
541 
542 static void
543 iscsi_callout(void *context)
544 {
545 	struct icl_pdu *request;
546 	struct iscsi_bhs_nop_out *bhsno;
547 	struct iscsi_session *is;
548 	bool reconnect_needed = false;
549 
550 	is = context;
551 
552 	ISCSI_SESSION_LOCK(is);
553 	if (is->is_terminating) {
554 		ISCSI_SESSION_UNLOCK(is);
555 		return;
556 	}
557 
558 	callout_schedule(&is->is_callout, 1 * hz);
559 
560 	if (is->is_conf.isc_enable == 0)
561 		goto out;
562 
563 	is->is_timeout++;
564 
565 	if (is->is_waiting_for_iscsid) {
566 		if (iscsid_timeout > 0 && is->is_timeout > iscsid_timeout) {
567 			ISCSI_SESSION_WARN(is, "timed out waiting for iscsid(8) "
568 			    "for %d seconds; reconnecting",
569 			    is->is_timeout);
570 			reconnect_needed = true;
571 		}
572 		goto out;
573 	}
574 
575 	if (is->is_login_phase) {
576 		if (login_timeout > 0 && is->is_timeout > login_timeout) {
577 			ISCSI_SESSION_WARN(is, "login timed out after %d seconds; "
578 			    "reconnecting", is->is_timeout);
579 			reconnect_needed = true;
580 		}
581 		goto out;
582 	}
583 
584 	if (ping_timeout <= 0) {
585 		/*
586 		 * Pings are disabled.  Don't send NOP-Out in this case.
587 		 * Reset the timeout, to avoid triggering reconnection,
588 		 * should the user decide to reenable them.
589 		 */
590 		is->is_timeout = 0;
591 		goto out;
592 	}
593 
594 	if (is->is_timeout >= ping_timeout) {
595 		ISCSI_SESSION_WARN(is, "no ping reply (NOP-In) after %d seconds; "
596 		    "reconnecting", ping_timeout);
597 		reconnect_needed = true;
598 		goto out;
599 	}
600 
601 	ISCSI_SESSION_UNLOCK(is);
602 
603 	/*
604 	 * If the ping was reset less than one second ago - which means
605 	 * that we've received some PDU during the last second - assume
606 	 * the traffic flows correctly and don't bother sending a NOP-Out.
607 	 *
608 	 * (It's 2 - one for one second, and one for incrementing is_timeout
609 	 * earlier in this routine.)
610 	 */
611 	if (is->is_timeout < 2)
612 		return;
613 
614 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
615 	if (request == NULL) {
616 		ISCSI_SESSION_WARN(is, "failed to allocate PDU");
617 		return;
618 	}
619 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
620 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
621 	    ISCSI_BHS_OPCODE_IMMEDIATE;
622 	bhsno->bhsno_flags = 0x80;
623 	bhsno->bhsno_target_transfer_tag = 0xffffffff;
624 	iscsi_pdu_queue(request);
625 	return;
626 
627 out:
628 	if (is->is_terminating) {
629 		ISCSI_SESSION_UNLOCK(is);
630 		return;
631 	}
632 
633 	ISCSI_SESSION_UNLOCK(is);
634 
635 	if (reconnect_needed)
636 		iscsi_session_reconnect(is);
637 }
638 
639 static void
640 iscsi_pdu_update_statsn(const struct icl_pdu *response)
641 {
642 	const struct iscsi_bhs_data_in *bhsdi;
643 	struct iscsi_session *is;
644 	uint32_t expcmdsn, maxcmdsn, statsn;
645 
646 	is = PDU_SESSION(response);
647 
648 	ISCSI_SESSION_LOCK_ASSERT(is);
649 
650 	/*
651 	 * We're only using fields common for all the response
652 	 * (target -> initiator) PDUs.
653 	 */
654 	bhsdi = (const struct iscsi_bhs_data_in *)response->ip_bhs;
655 	/*
656 	 * Ok, I lied.  In case of Data-In, "The fields StatSN, Status,
657 	 * and Residual Count only have meaningful content if the S bit
658 	 * is set to 1", so we also need to check the bit specific for
659 	 * Data-In PDU.
660 	 */
661 	if (bhsdi->bhsdi_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_IN ||
662 	    (bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0) {
663 		statsn = ntohl(bhsdi->bhsdi_statsn);
664 		if (statsn != is->is_statsn && statsn != (is->is_statsn + 1)) {
665 			/* XXX: This is normal situation for MCS */
666 			ISCSI_SESSION_WARN(is, "PDU 0x%x StatSN %u != "
667 			    "session ExpStatSN %u (or + 1); reconnecting",
668 			    bhsdi->bhsdi_opcode, statsn, is->is_statsn);
669 			iscsi_session_reconnect(is);
670 		}
671 		if (ISCSI_SNGT(statsn, is->is_statsn))
672 			is->is_statsn = statsn;
673 	}
674 
675 	expcmdsn = ntohl(bhsdi->bhsdi_expcmdsn);
676 	maxcmdsn = ntohl(bhsdi->bhsdi_maxcmdsn);
677 
678 	if (ISCSI_SNLT(maxcmdsn + 1, expcmdsn)) {
679 		ISCSI_SESSION_DEBUG(is,
680 		    "PDU MaxCmdSN %u + 1 < PDU ExpCmdSN %u; ignoring",
681 		    maxcmdsn, expcmdsn);
682 	} else {
683 		if (ISCSI_SNGT(maxcmdsn, is->is_maxcmdsn)) {
684 			is->is_maxcmdsn = maxcmdsn;
685 
686 			/*
687 			 * Command window increased; kick the maintanance thread
688 			 * to send out postponed commands.
689 			 */
690 			if (!STAILQ_EMPTY(&is->is_postponed))
691 				cv_signal(&is->is_maintenance_cv);
692 		} else if (ISCSI_SNLT(maxcmdsn, is->is_maxcmdsn)) {
693 			/* XXX: This is normal situation for MCS */
694 			ISCSI_SESSION_DEBUG(is,
695 			    "PDU MaxCmdSN %u < session MaxCmdSN %u; ignoring",
696 			    maxcmdsn, is->is_maxcmdsn);
697 		}
698 
699 		if (ISCSI_SNGT(expcmdsn, is->is_expcmdsn)) {
700 			is->is_expcmdsn = expcmdsn;
701 		} else if (ISCSI_SNLT(expcmdsn, is->is_expcmdsn)) {
702 			/* XXX: This is normal situation for MCS */
703 			ISCSI_SESSION_DEBUG(is,
704 			    "PDU ExpCmdSN %u < session ExpCmdSN %u; ignoring",
705 			    expcmdsn, is->is_expcmdsn);
706 		}
707 	}
708 
709 	/*
710 	 * Every incoming PDU - not just NOP-In - resets the ping timer.
711 	 * The purpose of the timeout is to reset the connection when it stalls;
712 	 * we don't want this to happen when NOP-In or NOP-Out ends up delayed
713 	 * in some queue.
714 	 */
715 	is->is_timeout = 0;
716 }
717 
718 static void
719 iscsi_receive_callback(struct icl_pdu *response)
720 {
721 	struct iscsi_session *is;
722 
723 	is = PDU_SESSION(response);
724 
725 	ISCSI_SESSION_LOCK(is);
726 
727 	iscsi_pdu_update_statsn(response);
728 
729 #ifdef ICL_KERNEL_PROXY
730 	if (is->is_login_phase) {
731 		if (is->is_login_pdu == NULL)
732 			is->is_login_pdu = response;
733 		else
734 			icl_pdu_free(response);
735 		ISCSI_SESSION_UNLOCK(is);
736 		cv_signal(&is->is_login_cv);
737 		return;
738 	}
739 #endif
740 
741 	/*
742 	 * The handling routine is responsible for freeing the PDU
743 	 * when it's no longer needed.
744 	 */
745 	switch (response->ip_bhs->bhs_opcode) {
746 	case ISCSI_BHS_OPCODE_NOP_IN:
747 		iscsi_pdu_handle_nop_in(response);
748 		ISCSI_SESSION_UNLOCK(is);
749 		break;
750 	case ISCSI_BHS_OPCODE_SCSI_RESPONSE:
751 		iscsi_pdu_handle_scsi_response(response);
752 		/* Session lock dropped inside. */
753 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
754 		break;
755 	case ISCSI_BHS_OPCODE_TASK_RESPONSE:
756 		iscsi_pdu_handle_task_response(response);
757 		ISCSI_SESSION_UNLOCK(is);
758 		break;
759 	case ISCSI_BHS_OPCODE_SCSI_DATA_IN:
760 		iscsi_pdu_handle_data_in(response);
761 		/* Session lock dropped inside. */
762 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
763 		break;
764 	case ISCSI_BHS_OPCODE_LOGOUT_RESPONSE:
765 		iscsi_pdu_handle_logout_response(response);
766 		ISCSI_SESSION_UNLOCK(is);
767 		break;
768 	case ISCSI_BHS_OPCODE_R2T:
769 		iscsi_pdu_handle_r2t(response);
770 		ISCSI_SESSION_UNLOCK(is);
771 		break;
772 	case ISCSI_BHS_OPCODE_ASYNC_MESSAGE:
773 		iscsi_pdu_handle_async_message(response);
774 		ISCSI_SESSION_UNLOCK(is);
775 		break;
776 	case ISCSI_BHS_OPCODE_REJECT:
777 		iscsi_pdu_handle_reject(response);
778 		ISCSI_SESSION_UNLOCK(is);
779 		break;
780 	default:
781 		ISCSI_SESSION_WARN(is, "received PDU with unsupported "
782 		    "opcode 0x%x; reconnecting",
783 		    response->ip_bhs->bhs_opcode);
784 		iscsi_session_reconnect(is);
785 		ISCSI_SESSION_UNLOCK(is);
786 		icl_pdu_free(response);
787 	}
788 }
789 
790 static void
791 iscsi_error_callback(struct icl_conn *ic)
792 {
793 	struct iscsi_session *is;
794 
795 	is = CONN_SESSION(ic);
796 
797 	ISCSI_SESSION_WARN(is, "connection error; reconnecting");
798 	iscsi_session_reconnect(is);
799 }
800 
801 static void
802 iscsi_pdu_handle_nop_in(struct icl_pdu *response)
803 {
804 	struct iscsi_session *is;
805 	struct iscsi_bhs_nop_out *bhsno;
806 	struct iscsi_bhs_nop_in *bhsni;
807 	struct icl_pdu *request;
808 	void *data = NULL;
809 	size_t datasize;
810 	int error;
811 
812 	is = PDU_SESSION(response);
813 	bhsni = (struct iscsi_bhs_nop_in *)response->ip_bhs;
814 
815 	if (bhsni->bhsni_target_transfer_tag == 0xffffffff) {
816 		/*
817 		 * Nothing to do; iscsi_pdu_update_statsn() already
818 		 * zeroed the timeout.
819 		 */
820 		icl_pdu_free(response);
821 		return;
822 	}
823 
824 	datasize = icl_pdu_data_segment_length(response);
825 	if (datasize > 0) {
826 		data = malloc(datasize, M_ISCSI, M_NOWAIT | M_ZERO);
827 		if (data == NULL) {
828 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
829 			    "reconnecting");
830 			icl_pdu_free(response);
831 			iscsi_session_reconnect(is);
832 			return;
833 		}
834 		icl_pdu_get_data(response, 0, data, datasize);
835 	}
836 
837 	request = icl_pdu_new(response->ip_conn, M_NOWAIT);
838 	if (request == NULL) {
839 		ISCSI_SESSION_WARN(is, "failed to allocate memory; "
840 		    "reconnecting");
841 		free(data, M_ISCSI);
842 		icl_pdu_free(response);
843 		iscsi_session_reconnect(is);
844 		return;
845 	}
846 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
847 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
848 	    ISCSI_BHS_OPCODE_IMMEDIATE;
849 	bhsno->bhsno_flags = 0x80;
850 	bhsno->bhsno_initiator_task_tag = 0xffffffff;
851 	bhsno->bhsno_target_transfer_tag = bhsni->bhsni_target_transfer_tag;
852 	if (datasize > 0) {
853 		error = icl_pdu_append_data(request, data, datasize, M_NOWAIT);
854 		if (error != 0) {
855 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
856 			    "reconnecting");
857 			free(data, M_ISCSI);
858 			icl_pdu_free(request);
859 			icl_pdu_free(response);
860 			iscsi_session_reconnect(is);
861 			return;
862 		}
863 		free(data, M_ISCSI);
864 	}
865 
866 	icl_pdu_free(response);
867 	iscsi_pdu_queue_locked(request);
868 }
869 
870 static void
871 iscsi_pdu_handle_scsi_response(struct icl_pdu *response)
872 {
873 	struct iscsi_bhs_scsi_response *bhssr;
874 	struct iscsi_outstanding *io;
875 	struct iscsi_session *is;
876 	union ccb *ccb;
877 	struct ccb_scsiio *csio;
878 	size_t data_segment_len, received;
879 	uint16_t sense_len;
880 	uint32_t resid;
881 
882 	is = PDU_SESSION(response);
883 
884 	bhssr = (struct iscsi_bhs_scsi_response *)response->ip_bhs;
885 	io = iscsi_outstanding_find(is, bhssr->bhssr_initiator_task_tag);
886 	if (io == NULL || io->io_ccb == NULL) {
887 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhssr->bhssr_initiator_task_tag);
888 		icl_pdu_free(response);
889 		iscsi_session_reconnect(is);
890 		ISCSI_SESSION_UNLOCK(is);
891 		return;
892 	}
893 
894 	ccb = io->io_ccb;
895 	if (bhssr->bhssr_response == BHSSR_RESPONSE_COMMAND_COMPLETED) {
896 		if (ntohl(bhssr->bhssr_expdatasn) != io->io_datasn) {
897 			ISCSI_SESSION_WARN(is,
898 			    "ExpDataSN mismatch in SCSI Response (%u vs %u)",
899 			    ntohl(bhssr->bhssr_expdatasn), io->io_datasn);
900 
901 			/*
902 			 * XXX: Permit an ExpDataSN of zero for errors.
903 			 *
904 			 * This doesn't conform to RFC 7143, but some
905 			 * targets seem to do this.
906 			 */
907 			if (bhssr->bhssr_status != 0 &&
908 			    bhssr->bhssr_expdatasn == htonl(0))
909 				goto skip_expdatasn;
910 
911 			icl_pdu_free(response);
912 			iscsi_session_reconnect(is);
913 			ISCSI_SESSION_UNLOCK(is);
914 			return;
915 		}
916 	} else {
917 		if (bhssr->bhssr_expdatasn != htonl(0)) {
918 			ISCSI_SESSION_WARN(is,
919 			    "ExpDataSN mismatch in SCSI Response (%u vs 0)",
920 			    ntohl(bhssr->bhssr_expdatasn));
921 			icl_pdu_free(response);
922 			iscsi_session_reconnect(is);
923 			ISCSI_SESSION_UNLOCK(is);
924 			return;
925 		}
926 	}
927 skip_expdatasn:
928 
929 	/*
930 	 * With iSER, after getting good response we can be sure
931 	 * that all the data has been successfully transferred.
932 	 */
933 	if (is->is_conn->ic_iser) {
934 		resid = ntohl(bhssr->bhssr_residual_count);
935 		if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW) {
936 			io->io_received = ccb->csio.dxfer_len - resid;
937 		} else if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_OVERFLOW) {
938 			ISCSI_SESSION_WARN(is, "overflow: target indicates %d", resid);
939 		} else {
940 			io->io_received = ccb->csio.dxfer_len;
941 		}
942 	}
943 
944 	received = io->io_received;
945 	iscsi_outstanding_remove(is, io);
946 	ISCSI_SESSION_UNLOCK(is);
947 
948 	if (bhssr->bhssr_response != BHSSR_RESPONSE_COMMAND_COMPLETED) {
949 		ISCSI_SESSION_WARN(is, "service response 0x%x", bhssr->bhssr_response);
950  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
951  			xpt_freeze_devq(ccb->ccb_h.path, 1);
952 			ISCSI_SESSION_DEBUG(is, "freezing devq");
953 		}
954  		ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
955 	} else if (bhssr->bhssr_status == 0) {
956 		ccb->ccb_h.status = CAM_REQ_CMP;
957 	} else {
958  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
959  			xpt_freeze_devq(ccb->ccb_h.path, 1);
960 			ISCSI_SESSION_DEBUG(is, "freezing devq");
961 		}
962  		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
963 		ccb->csio.scsi_status = bhssr->bhssr_status;
964 	}
965 
966 	csio = &ccb->csio;
967 	data_segment_len = icl_pdu_data_segment_length(response);
968 	if (data_segment_len > 0) {
969 		if (data_segment_len < sizeof(sense_len)) {
970 			ISCSI_SESSION_WARN(is, "truncated data segment (%zd bytes)",
971 			    data_segment_len);
972 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
973 				xpt_freeze_devq(ccb->ccb_h.path, 1);
974 				ISCSI_SESSION_DEBUG(is, "freezing devq");
975 			}
976 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
977 			goto out;
978 		}
979 		icl_pdu_get_data(response, 0, &sense_len, sizeof(sense_len));
980 		sense_len = ntohs(sense_len);
981 #if 0
982 		ISCSI_SESSION_DEBUG(is, "sense_len %d, data len %zd",
983 		    sense_len, data_segment_len);
984 #endif
985 		if (sizeof(sense_len) + sense_len > data_segment_len) {
986 			ISCSI_SESSION_WARN(is, "truncated data segment "
987 			    "(%zd bytes, should be %zd)",
988 			    data_segment_len, sizeof(sense_len) + sense_len);
989 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
990 				xpt_freeze_devq(ccb->ccb_h.path, 1);
991 				ISCSI_SESSION_DEBUG(is, "freezing devq");
992 			}
993 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
994 			goto out;
995 		} else if (sizeof(sense_len) + sense_len < data_segment_len)
996 			ISCSI_SESSION_WARN(is, "oversize data segment "
997 			    "(%zd bytes, should be %zd)",
998 			    data_segment_len, sizeof(sense_len) + sense_len);
999 		if (sense_len > csio->sense_len) {
1000 			ISCSI_SESSION_DEBUG(is, "truncating sense from %d to %d",
1001 			    sense_len, csio->sense_len);
1002 			sense_len = csio->sense_len;
1003 		}
1004 		icl_pdu_get_data(response, sizeof(sense_len), &csio->sense_data, sense_len);
1005 		csio->sense_resid = csio->sense_len - sense_len;
1006 		ccb->ccb_h.status |= CAM_AUTOSNS_VALID;
1007 	}
1008 
1009 out:
1010 	if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW)
1011 		csio->resid = ntohl(bhssr->bhssr_residual_count);
1012 
1013 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
1014 		KASSERT(received <= csio->dxfer_len,
1015 		    ("received > csio->dxfer_len"));
1016 		if (received < csio->dxfer_len) {
1017 			if (csio->resid != csio->dxfer_len - received) {
1018 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
1019 				    "target indicates %d, we calculated %zd",
1020 				    csio->resid, csio->dxfer_len - received);
1021 			}
1022 			csio->resid = csio->dxfer_len - received;
1023 		}
1024 	}
1025 
1026 	xpt_done(ccb);
1027 	icl_pdu_free(response);
1028 }
1029 
1030 static void
1031 iscsi_pdu_handle_task_response(struct icl_pdu *response)
1032 {
1033 	struct iscsi_bhs_task_management_response *bhstmr;
1034 	struct iscsi_outstanding *io, *aio;
1035 	struct iscsi_session *is;
1036 
1037 	is = PDU_SESSION(response);
1038 
1039 	bhstmr = (struct iscsi_bhs_task_management_response *)response->ip_bhs;
1040 	io = iscsi_outstanding_find(is, bhstmr->bhstmr_initiator_task_tag);
1041 	if (io == NULL || io->io_ccb != NULL) {
1042 		ISCSI_SESSION_WARN(is, "bad itt 0x%x",
1043 		    bhstmr->bhstmr_initiator_task_tag);
1044 		icl_pdu_free(response);
1045 		iscsi_session_reconnect(is);
1046 		return;
1047 	}
1048 
1049 	if (bhstmr->bhstmr_response != BHSTMR_RESPONSE_FUNCTION_COMPLETE) {
1050 		ISCSI_SESSION_WARN(is, "task response 0x%x",
1051 		    bhstmr->bhstmr_response);
1052 	} else {
1053 		aio = iscsi_outstanding_find(is, io->io_referenced_task_tag);
1054 		if (aio != NULL && aio->io_ccb != NULL)
1055 			iscsi_session_terminate_task(is, aio, CAM_REQ_ABORTED);
1056 	}
1057 
1058 	iscsi_outstanding_remove(is, io);
1059 	icl_pdu_free(response);
1060 }
1061 
1062 static void
1063 iscsi_pdu_handle_data_in(struct icl_pdu *response)
1064 {
1065 	struct iscsi_bhs_data_in *bhsdi;
1066 	struct iscsi_outstanding *io;
1067 	struct iscsi_session *is;
1068 	union ccb *ccb;
1069 	struct ccb_scsiio *csio;
1070 	size_t data_segment_len, received, oreceived;
1071 
1072 	is = PDU_SESSION(response);
1073 	bhsdi = (struct iscsi_bhs_data_in *)response->ip_bhs;
1074 	io = iscsi_outstanding_find(is, bhsdi->bhsdi_initiator_task_tag);
1075 	if (io == NULL || io->io_ccb == NULL) {
1076 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhsdi->bhsdi_initiator_task_tag);
1077 		icl_pdu_free(response);
1078 		iscsi_session_reconnect(is);
1079 		ISCSI_SESSION_UNLOCK(is);
1080 		return;
1081 	}
1082 
1083 	if (io->io_datasn != ntohl(bhsdi->bhsdi_datasn)) {
1084 		ISCSI_SESSION_WARN(is, "received Data-In PDU with "
1085 		    "DataSN %u, while expected %u; dropping connection",
1086 		    ntohl(bhsdi->bhsdi_datasn), io->io_datasn);
1087 		icl_pdu_free(response);
1088 		iscsi_session_reconnect(is);
1089 		ISCSI_SESSION_UNLOCK(is);
1090 		return;
1091 	}
1092 	io->io_datasn += response->ip_additional_pdus + 1;
1093 
1094 	data_segment_len = icl_pdu_data_segment_length(response);
1095 	if (data_segment_len == 0) {
1096 		/*
1097 		 * "The sending of 0 length data segments should be avoided,
1098 		 * but initiators and targets MUST be able to properly receive
1099 		 * 0 length data segments."
1100 		 */
1101 		ISCSI_SESSION_UNLOCK(is);
1102 		icl_pdu_free(response);
1103 		return;
1104 	}
1105 
1106 	/*
1107 	 * We need to track this for security reasons - without it, malicious target
1108 	 * could respond to SCSI READ without sending Data-In PDUs, which would result
1109 	 * in read operation on the initiator side returning random kernel data.
1110 	 */
1111 	if (ntohl(bhsdi->bhsdi_buffer_offset) != io->io_received) {
1112 		ISCSI_SESSION_WARN(is, "data out of order; expected offset %zd, got %zd",
1113 		    io->io_received, (size_t)ntohl(bhsdi->bhsdi_buffer_offset));
1114 		icl_pdu_free(response);
1115 		iscsi_session_reconnect(is);
1116 		ISCSI_SESSION_UNLOCK(is);
1117 		return;
1118 	}
1119 
1120 	ccb = io->io_ccb;
1121 	csio = &ccb->csio;
1122 
1123 	if (io->io_received + data_segment_len > csio->dxfer_len) {
1124 		ISCSI_SESSION_WARN(is, "oversize data segment (%zd bytes "
1125 		    "at offset %zd, buffer is %d)",
1126 		    data_segment_len, io->io_received, csio->dxfer_len);
1127 		icl_pdu_free(response);
1128 		iscsi_session_reconnect(is);
1129 		ISCSI_SESSION_UNLOCK(is);
1130 		return;
1131 	}
1132 
1133 	oreceived = io->io_received;
1134 	io->io_received += data_segment_len;
1135 	received = io->io_received;
1136 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0)
1137 		iscsi_outstanding_remove(is, io);
1138 	ISCSI_SESSION_UNLOCK(is);
1139 
1140 	icl_pdu_get_data(response, 0, csio->data_ptr + oreceived, data_segment_len);
1141 
1142 	/*
1143 	 * XXX: Check F.
1144 	 */
1145 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) == 0) {
1146 		/*
1147 		 * Nothing more to do.
1148 		 */
1149 		icl_pdu_free(response);
1150 		return;
1151 	}
1152 
1153 	//ISCSI_SESSION_DEBUG(is, "got S flag; status 0x%x", bhsdi->bhsdi_status);
1154 	if (bhsdi->bhsdi_status == 0) {
1155 		ccb->ccb_h.status = CAM_REQ_CMP;
1156 	} else {
1157 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
1158 			xpt_freeze_devq(ccb->ccb_h.path, 1);
1159 			ISCSI_SESSION_DEBUG(is, "freezing devq");
1160 		}
1161 		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
1162 		csio->scsi_status = bhsdi->bhsdi_status;
1163 	}
1164 
1165 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
1166 		KASSERT(received <= csio->dxfer_len,
1167 		    ("received > csio->dxfer_len"));
1168 		if (received < csio->dxfer_len) {
1169 			csio->resid = ntohl(bhsdi->bhsdi_residual_count);
1170 			if (csio->resid != csio->dxfer_len - received) {
1171 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
1172 				    "target indicates %d, we calculated %zd",
1173 				    csio->resid, csio->dxfer_len - received);
1174 			}
1175 			csio->resid = csio->dxfer_len - received;
1176 		}
1177 	}
1178 
1179 	xpt_done(ccb);
1180 	icl_pdu_free(response);
1181 }
1182 
1183 static void
1184 iscsi_pdu_handle_logout_response(struct icl_pdu *response)
1185 {
1186 
1187 	ISCSI_SESSION_DEBUG(PDU_SESSION(response), "logout response");
1188 	icl_pdu_free(response);
1189 }
1190 
1191 static void
1192 iscsi_pdu_handle_r2t(struct icl_pdu *response)
1193 {
1194 	struct icl_pdu *request;
1195 	struct iscsi_session *is;
1196 	struct iscsi_bhs_r2t *bhsr2t;
1197 	struct iscsi_bhs_data_out *bhsdo;
1198 	struct iscsi_outstanding *io;
1199 	struct ccb_scsiio *csio;
1200 	size_t off, len, max_send_data_segment_length, total_len;
1201 	int error;
1202 	uint32_t datasn = 0;
1203 
1204 	is = PDU_SESSION(response);
1205 
1206 	bhsr2t = (struct iscsi_bhs_r2t *)response->ip_bhs;
1207 	io = iscsi_outstanding_find(is, bhsr2t->bhsr2t_initiator_task_tag);
1208 	if (io == NULL || io->io_ccb == NULL) {
1209 		ISCSI_SESSION_WARN(is, "bad itt 0x%x; reconnecting",
1210 		    bhsr2t->bhsr2t_initiator_task_tag);
1211 		icl_pdu_free(response);
1212 		iscsi_session_reconnect(is);
1213 		return;
1214 	}
1215 
1216 	csio = &io->io_ccb->csio;
1217 
1218 	if ((csio->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_OUT) {
1219 		ISCSI_SESSION_WARN(is, "received R2T for read command; reconnecting");
1220 		icl_pdu_free(response);
1221 		iscsi_session_reconnect(is);
1222 		return;
1223 	}
1224 
1225 	/*
1226 	 * XXX: Verify R2TSN.
1227 	 */
1228 
1229 	off = ntohl(bhsr2t->bhsr2t_buffer_offset);
1230 	if (off > csio->dxfer_len) {
1231 		ISCSI_SESSION_WARN(is, "target requested invalid offset "
1232 		    "%zd, buffer is is %d; reconnecting", off, csio->dxfer_len);
1233 		icl_pdu_free(response);
1234 		iscsi_session_reconnect(is);
1235 		return;
1236 	}
1237 
1238 	total_len = ntohl(bhsr2t->bhsr2t_desired_data_transfer_length);
1239 	if (total_len == 0 || total_len > csio->dxfer_len) {
1240 		ISCSI_SESSION_WARN(is, "target requested invalid length "
1241 		    "%zd, buffer is %d; reconnecting", total_len, csio->dxfer_len);
1242 		icl_pdu_free(response);
1243 		iscsi_session_reconnect(is);
1244 		return;
1245 	}
1246 
1247 	//ISCSI_SESSION_DEBUG(is, "r2t; off %zd, len %zd", off, total_len);
1248 
1249 	if (is->is_conn->ic_hw_isomax != 0)
1250 		max_send_data_segment_length = is->is_conn->ic_hw_isomax;
1251 	else
1252 		max_send_data_segment_length =
1253 		    is->is_conn->ic_max_send_data_segment_length;
1254 	for (;;) {
1255 		len = total_len;
1256 
1257 		if (len > max_send_data_segment_length)
1258 			len = max_send_data_segment_length;
1259 
1260 		if (off + len > csio->dxfer_len) {
1261 			ISCSI_SESSION_WARN(is, "target requested invalid "
1262 			    "length/offset %zd, buffer is %d; reconnecting",
1263 			    off + len, csio->dxfer_len);
1264 			icl_pdu_free(response);
1265 			iscsi_session_reconnect(is);
1266 			return;
1267 		}
1268 
1269 		request = icl_pdu_new(response->ip_conn, M_NOWAIT);
1270 		if (request == NULL) {
1271 			icl_pdu_free(response);
1272 			iscsi_session_reconnect(is);
1273 			return;
1274 		}
1275 
1276 		bhsdo = (struct iscsi_bhs_data_out *)request->ip_bhs;
1277 		bhsdo->bhsdo_opcode = ISCSI_BHS_OPCODE_SCSI_DATA_OUT;
1278 		bhsdo->bhsdo_lun = bhsr2t->bhsr2t_lun;
1279 		bhsdo->bhsdo_initiator_task_tag =
1280 		    bhsr2t->bhsr2t_initiator_task_tag;
1281 		bhsdo->bhsdo_target_transfer_tag =
1282 		    bhsr2t->bhsr2t_target_transfer_tag;
1283 		bhsdo->bhsdo_datasn = htonl(datasn);
1284 		bhsdo->bhsdo_buffer_offset = htonl(off);
1285 		error = icl_pdu_append_data(request, csio->data_ptr + off, len,
1286 		    M_NOWAIT);
1287 		if (error != 0) {
1288 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
1289 			    "reconnecting");
1290 			icl_pdu_free(request);
1291 			icl_pdu_free(response);
1292 			iscsi_session_reconnect(is);
1293 			return;
1294 		}
1295 
1296 		datasn += howmany(len,
1297 		    is->is_conn->ic_max_send_data_segment_length);
1298 		off += len;
1299 		total_len -= len;
1300 
1301 		if (total_len == 0) {
1302 			bhsdo->bhsdo_flags |= BHSDO_FLAGS_F;
1303 			//ISCSI_SESSION_DEBUG(is, "setting F, off %zd", off);
1304 		} else {
1305 			//ISCSI_SESSION_DEBUG(is, "not finished, off %zd", off);
1306 		}
1307 
1308 		iscsi_pdu_queue_locked(request);
1309 
1310 		if (total_len == 0)
1311 			break;
1312 	}
1313 
1314 	icl_pdu_free(response);
1315 }
1316 
1317 static void
1318 iscsi_pdu_handle_async_message(struct icl_pdu *response)
1319 {
1320 	struct iscsi_bhs_asynchronous_message *bhsam;
1321 	struct iscsi_session *is;
1322 
1323 	is = PDU_SESSION(response);
1324 	bhsam = (struct iscsi_bhs_asynchronous_message *)response->ip_bhs;
1325 	switch (bhsam->bhsam_async_event) {
1326 	case BHSAM_EVENT_TARGET_REQUESTS_LOGOUT:
1327 		ISCSI_SESSION_WARN(is, "target requests logout; removing session");
1328 		iscsi_session_logout(is);
1329 		iscsi_session_terminate(is);
1330 		break;
1331 	case BHSAM_EVENT_TARGET_TERMINATES_CONNECTION:
1332 		ISCSI_SESSION_WARN(is, "target indicates it will drop the connection");
1333 		break;
1334 	case BHSAM_EVENT_TARGET_TERMINATES_SESSION:
1335 		ISCSI_SESSION_WARN(is, "target indicates it will drop the session");
1336 		break;
1337 	default:
1338 		/*
1339 		 * XXX: Technically, we're obligated to also handle
1340 		 * 	parameter renegotiation.
1341 		 */
1342 		ISCSI_SESSION_WARN(is, "ignoring AsyncEvent %d", bhsam->bhsam_async_event);
1343 		break;
1344 	}
1345 
1346 	icl_pdu_free(response);
1347 }
1348 
1349 static void
1350 iscsi_pdu_handle_reject(struct icl_pdu *response)
1351 {
1352 	struct iscsi_bhs_reject *bhsr;
1353 	struct iscsi_session *is;
1354 
1355 	is = PDU_SESSION(response);
1356 	bhsr = (struct iscsi_bhs_reject *)response->ip_bhs;
1357 	ISCSI_SESSION_WARN(is, "received Reject PDU, reason 0x%x; protocol error?",
1358 	    bhsr->bhsr_reason);
1359 
1360 	icl_pdu_free(response);
1361 }
1362 
1363 static int
1364 iscsi_ioctl_daemon_wait(struct iscsi_softc *sc,
1365     struct iscsi_daemon_request *request)
1366 {
1367 	struct iscsi_session *is;
1368 	struct icl_drv_limits idl;
1369 	int error;
1370 
1371 	sx_slock(&sc->sc_lock);
1372 	for (;;) {
1373 		TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1374 			ISCSI_SESSION_LOCK(is);
1375 			if (is->is_conf.isc_enable == 0 &&
1376 			    is->is_conf.isc_discovery == 0) {
1377 				ISCSI_SESSION_UNLOCK(is);
1378 				continue;
1379 			}
1380 			if (is->is_waiting_for_iscsid)
1381 				break;
1382 			ISCSI_SESSION_UNLOCK(is);
1383 		}
1384 
1385 		if (is == NULL) {
1386 			if (sc->sc_unloading) {
1387 				sx_sunlock(&sc->sc_lock);
1388 				return (ENXIO);
1389 			}
1390 
1391 			/*
1392 			 * No session requires attention from iscsid(8); wait.
1393 			 */
1394 			error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
1395 			if (error != 0) {
1396 				sx_sunlock(&sc->sc_lock);
1397 				return (error);
1398 			}
1399 			continue;
1400 		}
1401 
1402 		is->is_waiting_for_iscsid = false;
1403 		is->is_login_phase = true;
1404 		is->is_reason[0] = '\0';
1405 		ISCSI_SESSION_UNLOCK(is);
1406 
1407 		request->idr_session_id = is->is_id;
1408 		memcpy(&request->idr_isid, &is->is_isid,
1409 		    sizeof(request->idr_isid));
1410 		request->idr_tsih = 0;	/* New or reinstated session. */
1411 		memcpy(&request->idr_conf, &is->is_conf,
1412 		    sizeof(request->idr_conf));
1413 
1414 		error = icl_limits(is->is_conf.isc_offload,
1415 		    is->is_conf.isc_iser, &idl);
1416 		if (error != 0) {
1417 			ISCSI_SESSION_WARN(is, "icl_limits for offload \"%s\" "
1418 			    "failed with error %d", is->is_conf.isc_offload,
1419 			    error);
1420 			sx_sunlock(&sc->sc_lock);
1421 			return (error);
1422 		}
1423 		request->idr_limits.isl_max_recv_data_segment_length =
1424 		    idl.idl_max_recv_data_segment_length;
1425 		request->idr_limits.isl_max_send_data_segment_length =
1426 		    idl.idl_max_send_data_segment_length;
1427 		request->idr_limits.isl_max_burst_length =
1428 		    idl.idl_max_burst_length;
1429 		request->idr_limits.isl_first_burst_length =
1430 		    idl.idl_first_burst_length;
1431 
1432 		sx_sunlock(&sc->sc_lock);
1433 		return (0);
1434 	}
1435 }
1436 
1437 static int
1438 iscsi_ioctl_daemon_handoff(struct iscsi_softc *sc,
1439     struct iscsi_daemon_handoff *handoff)
1440 {
1441 	struct iscsi_session *is;
1442 	struct icl_conn *ic;
1443 	int error;
1444 
1445 	sx_slock(&sc->sc_lock);
1446 
1447 	/*
1448 	 * Find the session to hand off socket to.
1449 	 */
1450 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1451 		if (is->is_id == handoff->idh_session_id)
1452 			break;
1453 	}
1454 	if (is == NULL) {
1455 		sx_sunlock(&sc->sc_lock);
1456 		return (ESRCH);
1457 	}
1458 	ISCSI_SESSION_LOCK(is);
1459 	ic = is->is_conn;
1460 	if (is->is_conf.isc_discovery || is->is_terminating) {
1461 		ISCSI_SESSION_UNLOCK(is);
1462 		sx_sunlock(&sc->sc_lock);
1463 		return (EINVAL);
1464 	}
1465 	if (is->is_connected) {
1466 		/*
1467 		 * This might have happened because another iscsid(8)
1468 		 * instance handed off the connection in the meantime.
1469 		 * Just return.
1470 		 */
1471 		ISCSI_SESSION_WARN(is, "handoff on already connected "
1472 		    "session");
1473 		ISCSI_SESSION_UNLOCK(is);
1474 		sx_sunlock(&sc->sc_lock);
1475 		return (EBUSY);
1476 	}
1477 
1478 	strlcpy(is->is_target_alias, handoff->idh_target_alias,
1479 	    sizeof(is->is_target_alias));
1480 	is->is_tsih = handoff->idh_tsih;
1481 	is->is_statsn = handoff->idh_statsn;
1482 	is->is_protocol_level = handoff->idh_protocol_level;
1483 	is->is_initial_r2t = handoff->idh_initial_r2t;
1484 	is->is_immediate_data = handoff->idh_immediate_data;
1485 
1486 	ic->ic_max_recv_data_segment_length =
1487 	    handoff->idh_max_recv_data_segment_length;
1488 	ic->ic_max_send_data_segment_length =
1489 	    handoff->idh_max_send_data_segment_length;
1490 	is->is_max_burst_length = handoff->idh_max_burst_length;
1491 	is->is_first_burst_length = handoff->idh_first_burst_length;
1492 
1493 	if (handoff->idh_header_digest == ISCSI_DIGEST_CRC32C)
1494 		ic->ic_header_crc32c = true;
1495 	else
1496 		ic->ic_header_crc32c = false;
1497 	if (handoff->idh_data_digest == ISCSI_DIGEST_CRC32C)
1498 		ic->ic_data_crc32c = true;
1499 	else
1500 		ic->ic_data_crc32c = false;
1501 	ic->ic_maxtags = maxtags;
1502 
1503 	is->is_cmdsn = 0;
1504 	is->is_expcmdsn = 0;
1505 	is->is_maxcmdsn = 0;
1506 	is->is_waiting_for_iscsid = false;
1507 	is->is_login_phase = false;
1508 	is->is_timeout = 0;
1509 	is->is_connected = true;
1510 	is->is_reason[0] = '\0';
1511 
1512 	ISCSI_SESSION_UNLOCK(is);
1513 
1514 	/*
1515 	 * If we're going through the proxy, the idh_socket will be 0,
1516 	 * and the ICL module can simply ignore this call.  It can also
1517 	 * use it to determine it's no longer in the Login phase.
1518 	 */
1519 	error = icl_conn_handoff(ic, handoff->idh_socket);
1520 	if (error != 0) {
1521 		sx_sunlock(&sc->sc_lock);
1522 		iscsi_session_terminate(is);
1523 		return (error);
1524 	}
1525 
1526 	sx_sunlock(&sc->sc_lock);
1527 
1528 	if (is->is_sim != NULL) {
1529 		/*
1530 		 * When reconnecting, there already is SIM allocated for the session.
1531 		 */
1532 		KASSERT(is->is_simq_frozen, ("reconnect without frozen simq"));
1533 		ISCSI_SESSION_LOCK(is);
1534 		ISCSI_SESSION_DEBUG(is, "releasing");
1535 		is->is_simq_frozen = false;
1536 		xpt_release_simq(is->is_sim, 1);
1537 		ISCSI_SESSION_UNLOCK(is);
1538 
1539 	} else {
1540 		ISCSI_SESSION_LOCK(is);
1541 		is->is_devq = cam_simq_alloc(ic->ic_maxtags);
1542 		if (is->is_devq == NULL) {
1543 			ISCSI_SESSION_UNLOCK(is);
1544 			ISCSI_SESSION_WARN(is, "failed to allocate simq");
1545 			iscsi_session_terminate(is);
1546 			return (ENOMEM);
1547 		}
1548 
1549 		is->is_sim = cam_sim_alloc(iscsi_action, NULL, "iscsi",
1550 		    is, is->is_id /* unit */, &is->is_lock,
1551 		    1, ic->ic_maxtags, is->is_devq);
1552 		if (is->is_sim == NULL) {
1553 			ISCSI_SESSION_UNLOCK(is);
1554 			ISCSI_SESSION_WARN(is, "failed to allocate SIM");
1555 			cam_simq_free(is->is_devq);
1556 			iscsi_session_terminate(is);
1557 			return (ENOMEM);
1558 		}
1559 
1560 		if (xpt_bus_register(is->is_sim, NULL, 0) != 0) {
1561 			ISCSI_SESSION_UNLOCK(is);
1562 			ISCSI_SESSION_WARN(is, "failed to register bus");
1563 			iscsi_session_terminate(is);
1564 			return (ENOMEM);
1565 		}
1566 
1567 		error = xpt_create_path(&is->is_path, /*periph*/NULL,
1568 		    cam_sim_path(is->is_sim), CAM_TARGET_WILDCARD,
1569 		    CAM_LUN_WILDCARD);
1570 		if (error != CAM_REQ_CMP) {
1571 			ISCSI_SESSION_UNLOCK(is);
1572 			ISCSI_SESSION_WARN(is, "failed to create path");
1573 			iscsi_session_terminate(is);
1574 			return (ENOMEM);
1575 		}
1576 		ISCSI_SESSION_UNLOCK(is);
1577 	}
1578 
1579 	return (0);
1580 }
1581 
1582 static int
1583 iscsi_ioctl_daemon_fail(struct iscsi_softc *sc,
1584     struct iscsi_daemon_fail *fail)
1585 {
1586 	struct iscsi_session *is;
1587 
1588 	sx_slock(&sc->sc_lock);
1589 
1590 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1591 		if (is->is_id == fail->idf_session_id)
1592 			break;
1593 	}
1594 	if (is == NULL) {
1595 		sx_sunlock(&sc->sc_lock);
1596 		return (ESRCH);
1597 	}
1598 	ISCSI_SESSION_LOCK(is);
1599 	ISCSI_SESSION_DEBUG(is, "iscsid(8) failed: %s",
1600 	    fail->idf_reason);
1601 	strlcpy(is->is_reason, fail->idf_reason, sizeof(is->is_reason));
1602 	//is->is_waiting_for_iscsid = false;
1603 	//is->is_login_phase = true;
1604 	//iscsi_session_reconnect(is);
1605 	ISCSI_SESSION_UNLOCK(is);
1606 	sx_sunlock(&sc->sc_lock);
1607 
1608 	return (0);
1609 }
1610 
1611 #ifdef ICL_KERNEL_PROXY
1612 static int
1613 iscsi_ioctl_daemon_connect(struct iscsi_softc *sc,
1614     struct iscsi_daemon_connect *idc)
1615 {
1616 	struct iscsi_session *is;
1617 	struct sockaddr *from_sa, *to_sa;
1618 	int error;
1619 
1620 	sx_slock(&sc->sc_lock);
1621 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1622 		if (is->is_id == idc->idc_session_id)
1623 			break;
1624 	}
1625 	if (is == NULL) {
1626 		sx_sunlock(&sc->sc_lock);
1627 		return (ESRCH);
1628 	}
1629 	sx_sunlock(&sc->sc_lock);
1630 
1631 	if (idc->idc_from_addrlen > 0) {
1632 		error = getsockaddr(&from_sa, (void *)idc->idc_from_addr, idc->idc_from_addrlen);
1633 		if (error != 0) {
1634 			ISCSI_SESSION_WARN(is,
1635 			    "getsockaddr failed with error %d", error);
1636 			return (error);
1637 		}
1638 	} else {
1639 		from_sa = NULL;
1640 	}
1641 	error = getsockaddr(&to_sa, (void *)idc->idc_to_addr, idc->idc_to_addrlen);
1642 	if (error != 0) {
1643 		ISCSI_SESSION_WARN(is, "getsockaddr failed with error %d",
1644 		    error);
1645 		free(from_sa, M_SONAME);
1646 		return (error);
1647 	}
1648 
1649 	ISCSI_SESSION_LOCK(is);
1650 	is->is_statsn = 0;
1651 	is->is_cmdsn = 0;
1652 	is->is_expcmdsn = 0;
1653 	is->is_maxcmdsn = 0;
1654 	is->is_waiting_for_iscsid = false;
1655 	is->is_login_phase = true;
1656 	is->is_timeout = 0;
1657 	ISCSI_SESSION_UNLOCK(is);
1658 
1659 	error = icl_conn_connect(is->is_conn, idc->idc_domain,
1660 	    idc->idc_socktype, idc->idc_protocol, from_sa, to_sa);
1661 	free(from_sa, M_SONAME);
1662 	free(to_sa, M_SONAME);
1663 
1664 	/*
1665 	 * Digests are always disabled during login phase.
1666 	 */
1667 	is->is_conn->ic_header_crc32c = false;
1668 	is->is_conn->ic_data_crc32c = false;
1669 
1670 	return (error);
1671 }
1672 
1673 static int
1674 iscsi_ioctl_daemon_send(struct iscsi_softc *sc,
1675     struct iscsi_daemon_send *ids)
1676 {
1677 	struct iscsi_session *is;
1678 	struct icl_pdu *ip;
1679 	size_t datalen;
1680 	void *data;
1681 	int error;
1682 
1683 	sx_slock(&sc->sc_lock);
1684 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1685 		if (is->is_id == ids->ids_session_id)
1686 			break;
1687 	}
1688 	if (is == NULL) {
1689 		sx_sunlock(&sc->sc_lock);
1690 		return (ESRCH);
1691 	}
1692 	sx_sunlock(&sc->sc_lock);
1693 
1694 	if (is->is_login_phase == false)
1695 		return (EBUSY);
1696 
1697 	if (is->is_terminating || is->is_reconnecting)
1698 		return (EIO);
1699 
1700 	datalen = ids->ids_data_segment_len;
1701 	if (datalen > is->is_conn->ic_max_send_data_segment_length)
1702 		return (EINVAL);
1703 	if (datalen > 0) {
1704 		data = malloc(datalen, M_ISCSI, M_WAITOK);
1705 		error = copyin(ids->ids_data_segment, data, datalen);
1706 		if (error != 0) {
1707 			free(data, M_ISCSI);
1708 			return (error);
1709 		}
1710 	}
1711 
1712 	ip = icl_pdu_new(is->is_conn, M_WAITOK);
1713 	memcpy(ip->ip_bhs, ids->ids_bhs, sizeof(*ip->ip_bhs));
1714 	if (datalen > 0) {
1715 		error = icl_pdu_append_data(ip, data, datalen, M_WAITOK);
1716 		KASSERT(error == 0, ("icl_pdu_append_data(..., M_WAITOK) failed"));
1717 		free(data, M_ISCSI);
1718 	}
1719 	iscsi_pdu_queue(ip);
1720 
1721 	return (0);
1722 }
1723 
1724 static int
1725 iscsi_ioctl_daemon_receive(struct iscsi_softc *sc,
1726     struct iscsi_daemon_receive *idr)
1727 {
1728 	struct iscsi_session *is;
1729 	struct icl_pdu *ip;
1730 	void *data;
1731 	int error;
1732 
1733 	sx_slock(&sc->sc_lock);
1734 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1735 		if (is->is_id == idr->idr_session_id)
1736 			break;
1737 	}
1738 	if (is == NULL) {
1739 		sx_sunlock(&sc->sc_lock);
1740 		return (ESRCH);
1741 	}
1742 	sx_sunlock(&sc->sc_lock);
1743 
1744 	if (is->is_login_phase == false)
1745 		return (EBUSY);
1746 
1747 	ISCSI_SESSION_LOCK(is);
1748 	while (is->is_login_pdu == NULL &&
1749 	    is->is_terminating == false &&
1750 	    is->is_reconnecting == false) {
1751 		error = cv_wait_sig(&is->is_login_cv, &is->is_lock);
1752 		if (error != 0) {
1753 			ISCSI_SESSION_UNLOCK(is);
1754 			return (error);
1755 		}
1756 	}
1757 	if (is->is_terminating || is->is_reconnecting) {
1758 		ISCSI_SESSION_UNLOCK(is);
1759 		return (EIO);
1760 	}
1761 	ip = is->is_login_pdu;
1762 	is->is_login_pdu = NULL;
1763 	ISCSI_SESSION_UNLOCK(is);
1764 
1765 	if (ip->ip_data_len > idr->idr_data_segment_len) {
1766 		icl_pdu_free(ip);
1767 		return (EMSGSIZE);
1768 	}
1769 
1770 	copyout(ip->ip_bhs, idr->idr_bhs, sizeof(*ip->ip_bhs));
1771 	if (ip->ip_data_len > 0) {
1772 		data = malloc(ip->ip_data_len, M_ISCSI, M_WAITOK);
1773 		icl_pdu_get_data(ip, 0, data, ip->ip_data_len);
1774 		copyout(data, idr->idr_data_segment, ip->ip_data_len);
1775 		free(data, M_ISCSI);
1776 	}
1777 
1778 	icl_pdu_free(ip);
1779 
1780 	return (0);
1781 }
1782 #endif /* ICL_KERNEL_PROXY */
1783 
1784 static void
1785 iscsi_sanitize_session_conf(struct iscsi_session_conf *isc)
1786 {
1787 	/*
1788 	 * Just make sure all the fields are null-terminated.
1789 	 *
1790 	 * XXX: This is not particularly secure.  We should
1791 	 * 	create our own conf and then copy in relevant
1792 	 * 	fields.
1793 	 */
1794 	isc->isc_initiator[ISCSI_NAME_LEN - 1] = '\0';
1795 	isc->isc_initiator_addr[ISCSI_ADDR_LEN - 1] = '\0';
1796 	isc->isc_initiator_alias[ISCSI_ALIAS_LEN - 1] = '\0';
1797 	isc->isc_target[ISCSI_NAME_LEN - 1] = '\0';
1798 	isc->isc_target_addr[ISCSI_ADDR_LEN - 1] = '\0';
1799 	isc->isc_user[ISCSI_NAME_LEN - 1] = '\0';
1800 	isc->isc_secret[ISCSI_SECRET_LEN - 1] = '\0';
1801 	isc->isc_mutual_user[ISCSI_NAME_LEN - 1] = '\0';
1802 	isc->isc_mutual_secret[ISCSI_SECRET_LEN - 1] = '\0';
1803 }
1804 
1805 static bool
1806 iscsi_valid_session_conf(const struct iscsi_session_conf *isc)
1807 {
1808 
1809 	if (isc->isc_initiator[0] == '\0') {
1810 		ISCSI_DEBUG("empty isc_initiator");
1811 		return (false);
1812 	}
1813 
1814 	if (isc->isc_target_addr[0] == '\0') {
1815 		ISCSI_DEBUG("empty isc_target_addr");
1816 		return (false);
1817 	}
1818 
1819 	if (isc->isc_discovery != 0 && isc->isc_target[0] != 0) {
1820 		ISCSI_DEBUG("non-empty isc_target for discovery session");
1821 		return (false);
1822 	}
1823 
1824 	if (isc->isc_discovery == 0 && isc->isc_target[0] == 0) {
1825 		ISCSI_DEBUG("empty isc_target for non-discovery session");
1826 		return (false);
1827 	}
1828 
1829 	return (true);
1830 }
1831 
1832 static int
1833 iscsi_ioctl_session_add(struct iscsi_softc *sc, struct iscsi_session_add *isa)
1834 {
1835 	struct iscsi_session *is;
1836 	const struct iscsi_session *is2;
1837 	int error;
1838 
1839 	iscsi_sanitize_session_conf(&isa->isa_conf);
1840 	if (iscsi_valid_session_conf(&isa->isa_conf) == false)
1841 		return (EINVAL);
1842 
1843 	is = malloc(sizeof(*is), M_ISCSI, M_ZERO | M_WAITOK);
1844 	memcpy(&is->is_conf, &isa->isa_conf, sizeof(is->is_conf));
1845 
1846 	sx_xlock(&sc->sc_lock);
1847 
1848 	/*
1849 	 * Prevent duplicates.
1850 	 */
1851 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
1852 		if (!!is->is_conf.isc_discovery !=
1853 		    !!is2->is_conf.isc_discovery)
1854 			continue;
1855 
1856 		if (strcmp(is->is_conf.isc_target_addr,
1857 		    is2->is_conf.isc_target_addr) != 0)
1858 			continue;
1859 
1860 		if (is->is_conf.isc_discovery == 0 &&
1861 		    strcmp(is->is_conf.isc_target,
1862 		    is2->is_conf.isc_target) != 0)
1863 			continue;
1864 
1865 		sx_xunlock(&sc->sc_lock);
1866 		free(is, M_ISCSI);
1867 		return (EBUSY);
1868 	}
1869 
1870 	is->is_conn = icl_new_conn(is->is_conf.isc_offload,
1871 	    is->is_conf.isc_iser, "iscsi", &is->is_lock);
1872 	if (is->is_conn == NULL) {
1873 		sx_xunlock(&sc->sc_lock);
1874 		free(is, M_ISCSI);
1875 		return (EINVAL);
1876 	}
1877 	is->is_conn->ic_receive = iscsi_receive_callback;
1878 	is->is_conn->ic_error = iscsi_error_callback;
1879 	is->is_conn->ic_prv0 = is;
1880 	TAILQ_INIT(&is->is_outstanding);
1881 	STAILQ_INIT(&is->is_postponed);
1882 	mtx_init(&is->is_lock, "iscsi_lock", NULL, MTX_DEF);
1883 	cv_init(&is->is_maintenance_cv, "iscsi_mt");
1884 #ifdef ICL_KERNEL_PROXY
1885 	cv_init(&is->is_login_cv, "iscsi_login");
1886 #endif
1887 
1888 	/*
1889 	 * Set some default values, from RFC 3720, section 12.
1890 	 *
1891 	 * These values are updated by the handoff IOCTL, but are
1892 	 * needed prior to the handoff to support sending the ISER
1893 	 * login PDU.
1894 	 */
1895 	is->is_conn->ic_max_recv_data_segment_length = 8192;
1896 	is->is_conn->ic_max_send_data_segment_length = 8192;
1897 	is->is_max_burst_length = 262144;
1898 	is->is_first_burst_length = 65536;
1899 
1900 	is->is_softc = sc;
1901 	sc->sc_last_session_id++;
1902 	is->is_id = sc->sc_last_session_id;
1903 	is->is_isid[0] = 0x80; /* RFC 3720, 10.12.5: 10b, "Random" ISID. */
1904 	arc4rand(&is->is_isid[1], 5, 0);
1905 	is->is_tsih = 0;
1906 	callout_init(&is->is_callout, 1);
1907 
1908 	error = kthread_add(iscsi_maintenance_thread, is, NULL, NULL, 0, 0, "iscsimt");
1909 	if (error != 0) {
1910 		ISCSI_SESSION_WARN(is, "kthread_add(9) failed with error %d", error);
1911 		sx_xunlock(&sc->sc_lock);
1912 		return (error);
1913 	}
1914 
1915 	callout_reset(&is->is_callout, 1 * hz, iscsi_callout, is);
1916 	TAILQ_INSERT_TAIL(&sc->sc_sessions, is, is_next);
1917 
1918 	ISCSI_SESSION_LOCK(is);
1919 	/*
1920 	 * Don't notify iscsid(8) if the session is disabled and it's not
1921 	 * a discovery session,
1922 	 */
1923 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
1924 		ISCSI_SESSION_UNLOCK(is);
1925 		sx_xunlock(&sc->sc_lock);
1926 		return (0);
1927 	}
1928 
1929 	is->is_waiting_for_iscsid = true;
1930 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
1931 	ISCSI_SESSION_UNLOCK(is);
1932 	cv_signal(&sc->sc_cv);
1933 	sx_xunlock(&sc->sc_lock);
1934 	return (0);
1935 }
1936 
1937 static bool
1938 iscsi_session_conf_matches(unsigned int id1, const struct iscsi_session_conf *c1,
1939     unsigned int id2, const struct iscsi_session_conf *c2)
1940 {
1941 
1942 	if (id2 != 0 && id2 != id1)
1943 		return (false);
1944 	if (c2->isc_target[0] != '\0' &&
1945 	    strcmp(c1->isc_target, c2->isc_target) != 0)
1946 		return (false);
1947 	if (c2->isc_target_addr[0] != '\0' &&
1948 	    strcmp(c1->isc_target_addr, c2->isc_target_addr) != 0)
1949 		return (false);
1950 	return (true);
1951 }
1952 
1953 static int
1954 iscsi_ioctl_session_remove(struct iscsi_softc *sc,
1955     struct iscsi_session_remove *isr)
1956 {
1957 	struct iscsi_session *is, *tmp;
1958 	bool found = false;
1959 
1960 	iscsi_sanitize_session_conf(&isr->isr_conf);
1961 
1962 	sx_xlock(&sc->sc_lock);
1963 	TAILQ_FOREACH_SAFE(is, &sc->sc_sessions, is_next, tmp) {
1964 		ISCSI_SESSION_LOCK(is);
1965 		if (iscsi_session_conf_matches(is->is_id, &is->is_conf,
1966 		    isr->isr_session_id, &isr->isr_conf)) {
1967 			found = true;
1968 			iscsi_session_logout(is);
1969 			iscsi_session_terminate(is);
1970 		}
1971 		ISCSI_SESSION_UNLOCK(is);
1972 	}
1973 	sx_xunlock(&sc->sc_lock);
1974 
1975 	if (!found)
1976 		return (ESRCH);
1977 
1978 	return (0);
1979 }
1980 
1981 static int
1982 iscsi_ioctl_session_list(struct iscsi_softc *sc, struct iscsi_session_list *isl)
1983 {
1984 	int error;
1985 	unsigned int i = 0;
1986 	struct iscsi_session *is;
1987 	struct iscsi_session_state iss;
1988 
1989 	sx_slock(&sc->sc_lock);
1990 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1991 		if (i >= isl->isl_nentries) {
1992 			sx_sunlock(&sc->sc_lock);
1993 			return (EMSGSIZE);
1994 		}
1995 		memset(&iss, 0, sizeof(iss));
1996 		memcpy(&iss.iss_conf, &is->is_conf, sizeof(iss.iss_conf));
1997 		iss.iss_id = is->is_id;
1998 		strlcpy(iss.iss_target_alias, is->is_target_alias, sizeof(iss.iss_target_alias));
1999 		strlcpy(iss.iss_reason, is->is_reason, sizeof(iss.iss_reason));
2000 		strlcpy(iss.iss_offload, is->is_conn->ic_offload, sizeof(iss.iss_offload));
2001 
2002 		if (is->is_conn->ic_header_crc32c)
2003 			iss.iss_header_digest = ISCSI_DIGEST_CRC32C;
2004 		else
2005 			iss.iss_header_digest = ISCSI_DIGEST_NONE;
2006 
2007 		if (is->is_conn->ic_data_crc32c)
2008 			iss.iss_data_digest = ISCSI_DIGEST_CRC32C;
2009 		else
2010 			iss.iss_data_digest = ISCSI_DIGEST_NONE;
2011 
2012 		iss.iss_max_send_data_segment_length =
2013 		    is->is_conn->ic_max_send_data_segment_length;
2014 		iss.iss_max_recv_data_segment_length =
2015 		    is->is_conn->ic_max_recv_data_segment_length;
2016 		iss.iss_max_burst_length = is->is_max_burst_length;
2017 		iss.iss_first_burst_length = is->is_first_burst_length;
2018 		iss.iss_immediate_data = is->is_immediate_data;
2019 		iss.iss_connected = is->is_connected;
2020 
2021 		error = copyout(&iss, isl->isl_pstates + i, sizeof(iss));
2022 		if (error != 0) {
2023 			sx_sunlock(&sc->sc_lock);
2024 			return (error);
2025 		}
2026 		i++;
2027 	}
2028 	sx_sunlock(&sc->sc_lock);
2029 
2030 	isl->isl_nentries = i;
2031 
2032 	return (0);
2033 }
2034 
2035 static int
2036 iscsi_ioctl_session_modify(struct iscsi_softc *sc,
2037     struct iscsi_session_modify *ism)
2038 {
2039 	struct iscsi_session *is;
2040 	const struct iscsi_session *is2;
2041 
2042 	iscsi_sanitize_session_conf(&ism->ism_conf);
2043 	if (iscsi_valid_session_conf(&ism->ism_conf) == false)
2044 		return (EINVAL);
2045 
2046 	sx_xlock(&sc->sc_lock);
2047 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
2048 		ISCSI_SESSION_LOCK(is);
2049 		if (is->is_id == ism->ism_session_id) {
2050 			/* Note that the session remains locked. */
2051 			break;
2052 		}
2053 		ISCSI_SESSION_UNLOCK(is);
2054 	}
2055 	if (is == NULL) {
2056 		sx_xunlock(&sc->sc_lock);
2057 		return (ESRCH);
2058 	}
2059 
2060 	/*
2061 	 * Prevent duplicates.
2062 	 */
2063 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
2064 		if (is == is2)
2065 			continue;
2066 
2067 		if (!!ism->ism_conf.isc_discovery !=
2068 		    !!is2->is_conf.isc_discovery)
2069 			continue;
2070 
2071 		if (strcmp(ism->ism_conf.isc_target_addr,
2072 		    is2->is_conf.isc_target_addr) != 0)
2073 			continue;
2074 
2075 		if (ism->ism_conf.isc_discovery == 0 &&
2076 		    strcmp(ism->ism_conf.isc_target,
2077 		    is2->is_conf.isc_target) != 0)
2078 			continue;
2079 
2080 		ISCSI_SESSION_UNLOCK(is);
2081 		sx_xunlock(&sc->sc_lock);
2082 		return (EBUSY);
2083 	}
2084 
2085 	sx_xunlock(&sc->sc_lock);
2086 
2087 	memcpy(&is->is_conf, &ism->ism_conf, sizeof(is->is_conf));
2088 	ISCSI_SESSION_UNLOCK(is);
2089 
2090 	iscsi_session_reconnect(is);
2091 
2092 	return (0);
2093 }
2094 
2095 static int
2096 iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
2097     struct thread *td)
2098 {
2099 	struct iscsi_softc *sc;
2100 
2101 	sc = dev->si_drv1;
2102 
2103 	switch (cmd) {
2104 	case ISCSIDWAIT:
2105 		return (iscsi_ioctl_daemon_wait(sc,
2106 		    (struct iscsi_daemon_request *)arg));
2107 	case ISCSIDHANDOFF:
2108 		return (iscsi_ioctl_daemon_handoff(sc,
2109 		    (struct iscsi_daemon_handoff *)arg));
2110 	case ISCSIDFAIL:
2111 		return (iscsi_ioctl_daemon_fail(sc,
2112 		    (struct iscsi_daemon_fail *)arg));
2113 #ifdef ICL_KERNEL_PROXY
2114 	case ISCSIDCONNECT:
2115 		return (iscsi_ioctl_daemon_connect(sc,
2116 		    (struct iscsi_daemon_connect *)arg));
2117 	case ISCSIDSEND:
2118 		return (iscsi_ioctl_daemon_send(sc,
2119 		    (struct iscsi_daemon_send *)arg));
2120 	case ISCSIDRECEIVE:
2121 		return (iscsi_ioctl_daemon_receive(sc,
2122 		    (struct iscsi_daemon_receive *)arg));
2123 #endif /* ICL_KERNEL_PROXY */
2124 	case ISCSISADD:
2125 		return (iscsi_ioctl_session_add(sc,
2126 		    (struct iscsi_session_add *)arg));
2127 	case ISCSISREMOVE:
2128 		return (iscsi_ioctl_session_remove(sc,
2129 		    (struct iscsi_session_remove *)arg));
2130 	case ISCSISLIST:
2131 		return (iscsi_ioctl_session_list(sc,
2132 		    (struct iscsi_session_list *)arg));
2133 	case ISCSISMODIFY:
2134 		return (iscsi_ioctl_session_modify(sc,
2135 		    (struct iscsi_session_modify *)arg));
2136 	default:
2137 		return (EINVAL);
2138 	}
2139 }
2140 
2141 static struct iscsi_outstanding *
2142 iscsi_outstanding_find(struct iscsi_session *is, uint32_t initiator_task_tag)
2143 {
2144 	struct iscsi_outstanding *io;
2145 
2146 	ISCSI_SESSION_LOCK_ASSERT(is);
2147 
2148 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
2149 		if (io->io_initiator_task_tag == initiator_task_tag)
2150 			return (io);
2151 	}
2152 	return (NULL);
2153 }
2154 
2155 static struct iscsi_outstanding *
2156 iscsi_outstanding_find_ccb(struct iscsi_session *is, union ccb *ccb)
2157 {
2158 	struct iscsi_outstanding *io;
2159 
2160 	ISCSI_SESSION_LOCK_ASSERT(is);
2161 
2162 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
2163 		if (io->io_ccb == ccb)
2164 			return (io);
2165 	}
2166 	return (NULL);
2167 }
2168 
2169 static struct iscsi_outstanding *
2170 iscsi_outstanding_add(struct iscsi_session *is, struct icl_pdu *request,
2171     union ccb *ccb, uint32_t *initiator_task_tagp)
2172 {
2173 	struct iscsi_outstanding *io;
2174 	int error;
2175 
2176 	ISCSI_SESSION_LOCK_ASSERT(is);
2177 
2178 	io = uma_zalloc(iscsi_outstanding_zone, M_NOWAIT | M_ZERO);
2179 	if (io == NULL) {
2180 		ISCSI_SESSION_WARN(is, "failed to allocate %zd bytes",
2181 		    sizeof(*io));
2182 		return (NULL);
2183 	}
2184 
2185 	error = icl_conn_task_setup(is->is_conn, request, &ccb->csio,
2186 	    initiator_task_tagp, &io->io_icl_prv);
2187 	if (error != 0) {
2188 		ISCSI_SESSION_WARN(is,
2189 		    "icl_conn_task_setup() failed with error %d", error);
2190 		uma_zfree(iscsi_outstanding_zone, io);
2191 		return (NULL);
2192 	}
2193 
2194 	KASSERT(iscsi_outstanding_find(is, *initiator_task_tagp) == NULL,
2195 	    ("initiator_task_tag 0x%x already added", *initiator_task_tagp));
2196 
2197 	io->io_initiator_task_tag = *initiator_task_tagp;
2198 	io->io_ccb = ccb;
2199 	TAILQ_INSERT_TAIL(&is->is_outstanding, io, io_next);
2200 	return (io);
2201 }
2202 
2203 static void
2204 iscsi_outstanding_remove(struct iscsi_session *is, struct iscsi_outstanding *io)
2205 {
2206 
2207 	ISCSI_SESSION_LOCK_ASSERT(is);
2208 
2209 	icl_conn_task_done(is->is_conn, io->io_icl_prv);
2210 	TAILQ_REMOVE(&is->is_outstanding, io, io_next);
2211 	uma_zfree(iscsi_outstanding_zone, io);
2212 }
2213 
2214 static void
2215 iscsi_action_abort(struct iscsi_session *is, union ccb *ccb)
2216 {
2217 	struct icl_pdu *request;
2218 	struct iscsi_bhs_task_management_request *bhstmr;
2219 	struct ccb_abort *cab = &ccb->cab;
2220 	struct iscsi_outstanding *io, *aio;
2221 	uint32_t initiator_task_tag;
2222 
2223 	ISCSI_SESSION_LOCK_ASSERT(is);
2224 
2225 #if 0
2226 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2227 #else
2228 	if (is->is_login_phase) {
2229 		ccb->ccb_h.status = CAM_REQ_ABORTED;
2230 		xpt_done(ccb);
2231 		return;
2232 	}
2233 #endif
2234 
2235 	aio = iscsi_outstanding_find_ccb(is, cab->abort_ccb);
2236 	if (aio == NULL) {
2237 		ccb->ccb_h.status = CAM_REQ_CMP;
2238 		xpt_done(ccb);
2239 		return;
2240 	}
2241 
2242 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2243 	if (request == NULL) {
2244 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2245 		xpt_done(ccb);
2246 		return;
2247 	}
2248 
2249 	initiator_task_tag = is->is_initiator_task_tag++;
2250 	if (initiator_task_tag == 0xffffffff)
2251 		initiator_task_tag = is->is_initiator_task_tag++;
2252 
2253 	io = iscsi_outstanding_add(is, request, NULL, &initiator_task_tag);
2254 	if (io == NULL) {
2255 		icl_pdu_free(request);
2256 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2257 		xpt_done(ccb);
2258 		return;
2259 	}
2260 	io->io_referenced_task_tag = aio->io_initiator_task_tag;
2261 
2262 	bhstmr = (struct iscsi_bhs_task_management_request *)request->ip_bhs;
2263 	bhstmr->bhstmr_opcode = ISCSI_BHS_OPCODE_TASK_REQUEST;
2264 	bhstmr->bhstmr_function = 0x80 | BHSTMR_FUNCTION_ABORT_TASK;
2265 	bhstmr->bhstmr_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2266 	bhstmr->bhstmr_initiator_task_tag = initiator_task_tag;
2267 	bhstmr->bhstmr_referenced_task_tag = aio->io_initiator_task_tag;
2268 
2269 	iscsi_pdu_queue_locked(request);
2270 }
2271 
2272 static void
2273 iscsi_action_scsiio(struct iscsi_session *is, union ccb *ccb)
2274 {
2275 	struct icl_pdu *request;
2276 	struct iscsi_bhs_scsi_command *bhssc;
2277 	struct ccb_scsiio *csio;
2278 	struct iscsi_outstanding *io;
2279 	size_t len;
2280 	uint32_t initiator_task_tag;
2281 	int error;
2282 
2283 	ISCSI_SESSION_LOCK_ASSERT(is);
2284 
2285 #if 0
2286 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2287 #else
2288 	if (is->is_login_phase) {
2289 		ISCSI_SESSION_DEBUG(is, "called during login phase");
2290 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2291 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2292 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2293 		}
2294 		ccb->ccb_h.status = CAM_REQ_ABORTED | CAM_DEV_QFRZN;
2295 		xpt_done(ccb);
2296 		return;
2297 	}
2298 #endif
2299 
2300 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2301 	if (request == NULL) {
2302 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2303 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2304 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2305 		}
2306 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2307 		xpt_done(ccb);
2308 		return;
2309 	}
2310 
2311 	initiator_task_tag = is->is_initiator_task_tag++;
2312 	if (initiator_task_tag == 0xffffffff)
2313 		initiator_task_tag = is->is_initiator_task_tag++;
2314 
2315 	io = iscsi_outstanding_add(is, request, ccb, &initiator_task_tag);
2316 	if (io == NULL) {
2317 		icl_pdu_free(request);
2318 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2319 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2320 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2321 		}
2322 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2323 		xpt_done(ccb);
2324 		return;
2325 	}
2326 
2327 	csio = &ccb->csio;
2328 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
2329 	bhssc->bhssc_opcode = ISCSI_BHS_OPCODE_SCSI_COMMAND;
2330 	bhssc->bhssc_flags |= BHSSC_FLAGS_F;
2331 	switch (csio->ccb_h.flags & CAM_DIR_MASK) {
2332 	case CAM_DIR_IN:
2333 		bhssc->bhssc_flags |= BHSSC_FLAGS_R;
2334 		break;
2335 	case CAM_DIR_OUT:
2336 		bhssc->bhssc_flags |= BHSSC_FLAGS_W;
2337 		break;
2338 	}
2339 
2340 	if ((ccb->ccb_h.flags & CAM_TAG_ACTION_VALID) != 0) {
2341 		switch (csio->tag_action) {
2342 		case MSG_HEAD_OF_Q_TAG:
2343 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_HOQ;
2344 			break;
2345 		case MSG_ORDERED_Q_TAG:
2346 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ORDERED;
2347 			break;
2348 		case MSG_ACA_TASK:
2349 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ACA;
2350 			break;
2351 		case MSG_SIMPLE_Q_TAG:
2352 		default:
2353 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_SIMPLE;
2354 			break;
2355 		}
2356 	} else
2357 		bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_UNTAGGED;
2358 
2359 	if (is->is_protocol_level >= 2) {
2360 		bhssc->bhssc_pri = (csio->priority << BHSSC_PRI_SHIFT) &
2361 		    BHSSC_PRI_MASK;
2362 	}
2363 
2364 	bhssc->bhssc_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2365 	bhssc->bhssc_initiator_task_tag = initiator_task_tag;
2366 	bhssc->bhssc_expected_data_transfer_length = htonl(csio->dxfer_len);
2367 	KASSERT(csio->cdb_len <= sizeof(bhssc->bhssc_cdb),
2368 	    ("unsupported CDB size %zd", (size_t)csio->cdb_len));
2369 
2370 	if (csio->ccb_h.flags & CAM_CDB_POINTER)
2371 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_ptr, csio->cdb_len);
2372 	else
2373 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_bytes, csio->cdb_len);
2374 
2375 	if (is->is_immediate_data &&
2376 	    (csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT) {
2377 		len = csio->dxfer_len;
2378 		//ISCSI_SESSION_DEBUG(is, "adding %zd of immediate data", len);
2379 		if (len > is->is_first_burst_length) {
2380 			ISCSI_SESSION_DEBUG(is, "len %zd -> %d", len, is->is_first_burst_length);
2381 			len = is->is_first_burst_length;
2382 		}
2383 		if (len > is->is_conn->ic_max_send_data_segment_length) {
2384 			ISCSI_SESSION_DEBUG(is, "len %zd -> %d", len,
2385 			    is->is_conn->ic_max_send_data_segment_length);
2386 			len = is->is_conn->ic_max_send_data_segment_length;
2387 		}
2388 
2389 		error = icl_pdu_append_data(request, csio->data_ptr, len, M_NOWAIT);
2390 		if (error != 0) {
2391 			iscsi_outstanding_remove(is, io);
2392 			icl_pdu_free(request);
2393 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2394 				xpt_freeze_devq(ccb->ccb_h.path, 1);
2395 				ISCSI_SESSION_DEBUG(is, "freezing devq");
2396 			}
2397 			ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2398 			xpt_done(ccb);
2399 			return;
2400 		}
2401 	}
2402 	iscsi_pdu_queue_locked(request);
2403 }
2404 
2405 static void
2406 iscsi_action(struct cam_sim *sim, union ccb *ccb)
2407 {
2408 	struct iscsi_session *is;
2409 
2410 	is = cam_sim_softc(sim);
2411 
2412 	ISCSI_SESSION_LOCK_ASSERT(is);
2413 
2414 	if (is->is_terminating ||
2415 	    (is->is_connected == false && fail_on_disconnection)) {
2416 		ccb->ccb_h.status = CAM_DEV_NOT_THERE;
2417 		xpt_done(ccb);
2418 		return;
2419 	}
2420 
2421 	/*
2422 	 * Make sure CAM doesn't sneak in a CCB just after freezing the queue.
2423 	 */
2424 	if (is->is_simq_frozen == true) {
2425 		ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
2426 		ccb->ccb_h.status |= CAM_REQUEUE_REQ;
2427 		/* Don't freeze the devq - the SIM queue is already frozen. */
2428 		xpt_done(ccb);
2429 		return;
2430 	}
2431 
2432 	switch (ccb->ccb_h.func_code) {
2433 	case XPT_PATH_INQ:
2434 	{
2435 		struct ccb_pathinq *cpi = &ccb->cpi;
2436 
2437 		cpi->version_num = 1;
2438 		cpi->hba_inquiry = PI_TAG_ABLE;
2439 		cpi->target_sprt = 0;
2440 		cpi->hba_misc = PIM_EXTLUNS;
2441 		/*
2442 		 * XXX: It shouldn't ever be NULL; this could be turned
2443 		 *      into a KASSERT eventually.
2444 		 */
2445 		if (is->is_conn == NULL)
2446 			ISCSI_WARN("NULL conn");
2447 		else if (is->is_conn->ic_unmapped)
2448 			cpi->hba_misc |= PIM_UNMAPPED;
2449 		cpi->hba_eng_cnt = 0;
2450 		cpi->max_target = 0;
2451 		/*
2452 		 * Note that the variable below is only relevant for targets
2453 		 * that don't claim compliance with anything above SPC2, which
2454 		 * means they don't support REPORT_LUNS.
2455 		 */
2456 		cpi->max_lun = 255;
2457 		cpi->initiator_id = ~0;
2458 		strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
2459 		strlcpy(cpi->hba_vid, "iSCSI", HBA_IDLEN);
2460 		strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
2461 		cpi->unit_number = cam_sim_unit(sim);
2462 		cpi->bus_id = cam_sim_bus(sim);
2463 		cpi->base_transfer_speed = 150000; /* XXX */
2464 		cpi->transport = XPORT_ISCSI;
2465 		cpi->transport_version = 0;
2466 		cpi->protocol = PROTO_SCSI;
2467 		cpi->protocol_version = SCSI_REV_SPC3;
2468 		cpi->maxio = maxphys;
2469 		cpi->ccb_h.status = CAM_REQ_CMP;
2470 		break;
2471 	}
2472 	case XPT_GET_TRAN_SETTINGS:
2473 	{
2474 		struct ccb_trans_settings	*cts;
2475 		struct ccb_trans_settings_scsi	*scsi;
2476 
2477 		cts = &ccb->cts;
2478 		scsi = &cts->proto_specific.scsi;
2479 
2480 		cts->protocol = PROTO_SCSI;
2481 		cts->protocol_version = SCSI_REV_SPC3;
2482 		cts->transport = XPORT_ISCSI;
2483 		cts->transport_version = 0;
2484 		scsi->valid = CTS_SCSI_VALID_TQ;
2485 		scsi->flags = CTS_SCSI_FLAGS_TAG_ENB;
2486 		cts->ccb_h.status = CAM_REQ_CMP;
2487 		break;
2488 	}
2489 	case XPT_CALC_GEOMETRY:
2490 		cam_calc_geometry(&ccb->ccg, /*extended*/1);
2491 		ccb->ccb_h.status = CAM_REQ_CMP;
2492 		break;
2493 #if 0
2494 	/*
2495 	 * XXX: What's the point?
2496 	 */
2497 	case XPT_RESET_BUS:
2498 	case XPT_TERM_IO:
2499 		ISCSI_SESSION_DEBUG(is, "faking success for reset, abort, or term_io");
2500 		ccb->ccb_h.status = CAM_REQ_CMP;
2501 		break;
2502 #endif
2503 	case XPT_ABORT:
2504 		iscsi_action_abort(is, ccb);
2505 		return;
2506 	case XPT_SCSI_IO:
2507 		iscsi_action_scsiio(is, ccb);
2508 		return;
2509 	default:
2510 #if 0
2511 		ISCSI_SESSION_DEBUG(is, "got unsupported code 0x%x", ccb->ccb_h.func_code);
2512 #endif
2513 		ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
2514 		break;
2515 	}
2516 	xpt_done(ccb);
2517 }
2518 
2519 static void
2520 iscsi_terminate_sessions(struct iscsi_softc *sc)
2521 {
2522 	struct iscsi_session *is;
2523 
2524 	sx_slock(&sc->sc_lock);
2525 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next)
2526 		iscsi_session_terminate(is);
2527 	while(!TAILQ_EMPTY(&sc->sc_sessions)) {
2528 		ISCSI_DEBUG("waiting for sessions to terminate");
2529 		cv_wait(&sc->sc_cv, &sc->sc_lock);
2530 	}
2531 	ISCSI_DEBUG("all sessions terminated");
2532 	sx_sunlock(&sc->sc_lock);
2533 }
2534 
2535 static void
2536 iscsi_shutdown_pre(struct iscsi_softc *sc)
2537 {
2538 	struct iscsi_session *is;
2539 
2540 	if (!fail_on_shutdown)
2541 		return;
2542 
2543 	/*
2544 	 * If we have any sessions waiting for reconnection, request
2545 	 * maintenance thread to fail them immediately instead of waiting
2546 	 * for reconnect timeout.
2547 	 *
2548 	 * This prevents LUNs with mounted filesystems that are supported
2549 	 * by disconnected iSCSI sessions from hanging, however it will
2550 	 * fail all queued BIOs.
2551 	 */
2552 	ISCSI_DEBUG("forcing failing all disconnected sessions due to shutdown");
2553 
2554 	fail_on_disconnection = 1;
2555 
2556 	sx_slock(&sc->sc_lock);
2557 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
2558 		ISCSI_SESSION_LOCK(is);
2559 		if (!is->is_connected) {
2560 			ISCSI_SESSION_DEBUG(is, "force failing disconnected session early");
2561 			iscsi_session_reconnect(is);
2562 		}
2563 		ISCSI_SESSION_UNLOCK(is);
2564 	}
2565 	sx_sunlock(&sc->sc_lock);
2566 }
2567 
2568 static void
2569 iscsi_shutdown_post(struct iscsi_softc *sc)
2570 {
2571 
2572 	if (!KERNEL_PANICKED()) {
2573 		ISCSI_DEBUG("removing all sessions due to shutdown");
2574 		iscsi_terminate_sessions(sc);
2575 	}
2576 }
2577 
2578 static int
2579 iscsi_load(void)
2580 {
2581 	int error;
2582 
2583 	sc = malloc(sizeof(*sc), M_ISCSI, M_ZERO | M_WAITOK);
2584 	sx_init(&sc->sc_lock, "iscsi");
2585 	TAILQ_INIT(&sc->sc_sessions);
2586 	cv_init(&sc->sc_cv, "iscsi_cv");
2587 
2588 	iscsi_outstanding_zone = uma_zcreate("iscsi_outstanding",
2589 	    sizeof(struct iscsi_outstanding), NULL, NULL, NULL, NULL,
2590 	    UMA_ALIGN_PTR, 0);
2591 
2592 	error = make_dev_p(MAKEDEV_CHECKNAME, &sc->sc_cdev, &iscsi_cdevsw,
2593 	    NULL, UID_ROOT, GID_WHEEL, 0600, "iscsi");
2594 	if (error != 0) {
2595 		ISCSI_WARN("failed to create device node, error %d", error);
2596 		return (error);
2597 	}
2598 	sc->sc_cdev->si_drv1 = sc;
2599 
2600 	sc->sc_shutdown_pre_eh = EVENTHANDLER_REGISTER(shutdown_pre_sync,
2601 	    iscsi_shutdown_pre, sc, SHUTDOWN_PRI_FIRST);
2602 	/*
2603 	 * shutdown_post_sync needs to run after filesystem shutdown and before
2604 	 * CAM shutdown - otherwise when rebooting with an iSCSI session that is
2605 	 * disconnected but has outstanding requests, dashutdown() will hang on
2606 	 * cam_periph_runccb().
2607 	 */
2608 	sc->sc_shutdown_post_eh = EVENTHANDLER_REGISTER(shutdown_post_sync,
2609 	    iscsi_shutdown_post, sc, SHUTDOWN_PRI_DEFAULT - 1);
2610 
2611 	return (0);
2612 }
2613 
2614 static int
2615 iscsi_unload(void)
2616 {
2617 
2618 	/* Awaken any threads asleep in iscsi_ioctl(). */
2619 	sx_xlock(&sc->sc_lock);
2620 	sc->sc_unloading = true;
2621 	cv_signal(&sc->sc_cv);
2622 	sx_xunlock(&sc->sc_lock);
2623 
2624 	if (sc->sc_cdev != NULL) {
2625 		ISCSI_DEBUG("removing device node");
2626 		destroy_dev(sc->sc_cdev);
2627 		ISCSI_DEBUG("device node removed");
2628 	}
2629 
2630 	if (sc->sc_shutdown_pre_eh != NULL)
2631 		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, sc->sc_shutdown_pre_eh);
2632 	if (sc->sc_shutdown_post_eh != NULL)
2633 		EVENTHANDLER_DEREGISTER(shutdown_post_sync, sc->sc_shutdown_post_eh);
2634 
2635 	iscsi_terminate_sessions(sc);
2636 
2637 	uma_zdestroy(iscsi_outstanding_zone);
2638 	sx_destroy(&sc->sc_lock);
2639 	cv_destroy(&sc->sc_cv);
2640 	free(sc, M_ISCSI);
2641 	return (0);
2642 }
2643 
2644 static int
2645 iscsi_quiesce(void)
2646 {
2647 	sx_slock(&sc->sc_lock);
2648 	if (!TAILQ_EMPTY(&sc->sc_sessions)) {
2649 		sx_sunlock(&sc->sc_lock);
2650 		return (EBUSY);
2651 	}
2652 	sx_sunlock(&sc->sc_lock);
2653 	return (0);
2654 }
2655 
2656 static int
2657 iscsi_modevent(module_t mod, int what, void *arg)
2658 {
2659 	int error;
2660 
2661 	switch (what) {
2662 	case MOD_LOAD:
2663 		error = iscsi_load();
2664 		break;
2665 	case MOD_UNLOAD:
2666 		error = iscsi_unload();
2667 		break;
2668 	case MOD_QUIESCE:
2669 		error = iscsi_quiesce();
2670 		break;
2671 	default:
2672 		error = EINVAL;
2673 		break;
2674 	}
2675 	return (error);
2676 }
2677 
2678 moduledata_t iscsi_data = {
2679 	"iscsi",
2680 	iscsi_modevent,
2681 	0
2682 };
2683 
2684 DECLARE_MODULE(iscsi, iscsi_data, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
2685 MODULE_DEPEND(iscsi, cam, 1, 1, 1);
2686 MODULE_DEPEND(iscsi, icl, 1, 1, 1);
2687