xref: /freebsd/sys/dev/iscsi/iscsi.c (revision 685dc743dc3b5645e34836464128e1c0558b404b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/param.h>
34 #include <sys/bio.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/mbuf.h>
45 #include <sys/mutex.h>
46 #include <sys/module.h>
47 #include <sys/socket.h>
48 #include <sys/sockopt.h>
49 #include <sys/sysctl.h>
50 #include <sys/systm.h>
51 #include <sys/sx.h>
52 #include <vm/uma.h>
53 
54 #include <cam/cam.h>
55 #include <cam/cam_ccb.h>
56 #include <cam/cam_xpt.h>
57 #include <cam/cam_debug.h>
58 #include <cam/cam_sim.h>
59 #include <cam/cam_xpt_sim.h>
60 #include <cam/cam_xpt_periph.h>
61 #include <cam/cam_periph.h>
62 #include <cam/scsi/scsi_all.h>
63 #include <cam/scsi/scsi_message.h>
64 
65 #include <dev/iscsi/icl.h>
66 #include <dev/iscsi/icl_wrappers.h>
67 #include <dev/iscsi/iscsi_ioctl.h>
68 #include <dev/iscsi/iscsi_proto.h>
69 #include <dev/iscsi/iscsi.h>
70 
71 #ifdef ICL_KERNEL_PROXY
72 #include <sys/socketvar.h>
73 #endif
74 
75 #ifdef ICL_KERNEL_PROXY
76 FEATURE(iscsi_kernel_proxy, "iSCSI initiator built with ICL_KERNEL_PROXY");
77 #endif
78 
79 #ifdef COMPAT_FREEBSD13
80 struct iscsi_daemon_request13 {
81 	unsigned int			idr_session_id;
82 	struct iscsi_session_conf	idr_conf;
83 	uint8_t				idr_isid[6];
84 	uint16_t			idr_tsih;
85 	uint16_t			idr_spare_cid;
86 	struct iscsi_session_limits	idr_limits;
87 	int				idr_spare[4];
88 };
89 
90 #define	ISCSIDWAIT13	_IOR('I', 0x01, struct iscsi_daemon_request13)
91 #endif
92 
93 /*
94  * XXX: This is global so the iscsi_unload() can access it.
95  * 	Think about how to do this properly.
96  */
97 static struct iscsi_softc	*sc;
98 
99 SYSCTL_NODE(_kern, OID_AUTO, iscsi, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
100     "iSCSI initiator");
101 static int debug = 1;
102 SYSCTL_INT(_kern_iscsi, OID_AUTO, debug, CTLFLAG_RWTUN,
103     &debug, 0, "Enable debug messages");
104 
105 static int ping_timeout = 5;
106 SYSCTL_INT(_kern_iscsi, OID_AUTO, ping_timeout, CTLFLAG_RWTUN, &ping_timeout,
107     0, "Timeout for ping (NOP-Out) requests, in seconds");
108 static int iscsid_timeout = 60;
109 SYSCTL_INT(_kern_iscsi, OID_AUTO, iscsid_timeout, CTLFLAG_RWTUN, &iscsid_timeout,
110     0, "Time to wait for iscsid(8) to handle reconnection, in seconds");
111 static int login_timeout = 60;
112 SYSCTL_INT(_kern_iscsi, OID_AUTO, login_timeout, CTLFLAG_RWTUN, &login_timeout,
113     0, "Time to wait for iscsid(8) to finish Login Phase, in seconds");
114 static int maxtags = 255;
115 SYSCTL_INT(_kern_iscsi, OID_AUTO, maxtags, CTLFLAG_RWTUN, &maxtags,
116     0, "Max number of IO requests queued");
117 static int fail_on_disconnection = 0;
118 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_disconnection, CTLFLAG_RWTUN,
119     &fail_on_disconnection, 0, "Destroy CAM SIM on connection failure");
120 static int fail_on_shutdown = 1;
121 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_shutdown, CTLFLAG_RWTUN,
122     &fail_on_shutdown, 0, "Fail disconnected sessions on shutdown");
123 
124 static MALLOC_DEFINE(M_ISCSI, "iSCSI", "iSCSI initiator");
125 static uma_zone_t iscsi_outstanding_zone;
126 
127 #define	CONN_SESSION(X)	((struct iscsi_session *)X->ic_prv0)
128 #define	PDU_SESSION(X)	(CONN_SESSION(X->ip_conn))
129 
130 #define	ISCSI_DEBUG(X, ...)						\
131 	do {								\
132 		if (debug > 1) 						\
133 			printf("%s: " X "\n", __func__, ## __VA_ARGS__);\
134 	} while (0)
135 
136 #define	ISCSI_WARN(X, ...)						\
137 	do {								\
138 		if (debug > 0) {					\
139 			printf("WARNING: %s: " X "\n",			\
140 			    __func__, ## __VA_ARGS__);			\
141 		}							\
142 	} while (0)
143 
144 #define	ISCSI_SESSION_DEBUG(S, X, ...)					\
145 	do {								\
146 		if (debug > 1) {					\
147 			printf("%s: %s (%s): " X "\n",			\
148 			    __func__, S->is_conf.isc_target_addr,	\
149 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
150 		}							\
151 	} while (0)
152 
153 #define	ISCSI_SESSION_WARN(S, X, ...)					\
154 	do {								\
155 		if (debug > 0) {					\
156 			printf("WARNING: %s (%s): " X "\n",		\
157 			    S->is_conf.isc_target_addr,			\
158 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
159 		}							\
160 	} while (0)
161 
162 #define ISCSI_SESSION_LOCK(X)		mtx_lock(&X->is_lock)
163 #define ISCSI_SESSION_UNLOCK(X)		mtx_unlock(&X->is_lock)
164 #define ISCSI_SESSION_LOCK_ASSERT(X)	mtx_assert(&X->is_lock, MA_OWNED)
165 #define ISCSI_SESSION_LOCK_ASSERT_NOT(X) mtx_assert(&X->is_lock, MA_NOTOWNED)
166 
167 static int	iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg,
168 		    int mode, struct thread *td);
169 
170 static struct cdevsw iscsi_cdevsw = {
171      .d_version = D_VERSION,
172      .d_ioctl   = iscsi_ioctl,
173      .d_name    = "iscsi",
174 };
175 
176 static void	iscsi_pdu_queue_locked(struct icl_pdu *request);
177 static void	iscsi_pdu_queue(struct icl_pdu *request);
178 static void	iscsi_pdu_update_statsn(const struct icl_pdu *response);
179 static void	iscsi_pdu_handle_nop_in(struct icl_pdu *response);
180 static void	iscsi_pdu_handle_scsi_response(struct icl_pdu *response);
181 static void	iscsi_pdu_handle_task_response(struct icl_pdu *response);
182 static void	iscsi_pdu_handle_data_in(struct icl_pdu *response);
183 static void	iscsi_pdu_handle_logout_response(struct icl_pdu *response);
184 static void	iscsi_pdu_handle_r2t(struct icl_pdu *response);
185 static void	iscsi_pdu_handle_async_message(struct icl_pdu *response);
186 static void	iscsi_pdu_handle_reject(struct icl_pdu *response);
187 static void	iscsi_session_reconnect(struct iscsi_session *is);
188 static void	iscsi_session_terminate(struct iscsi_session *is);
189 static void	iscsi_action(struct cam_sim *sim, union ccb *ccb);
190 static struct iscsi_outstanding	*iscsi_outstanding_find(struct iscsi_session *is,
191 		    uint32_t initiator_task_tag);
192 static struct iscsi_outstanding	*iscsi_outstanding_add(struct iscsi_session *is,
193 		    struct icl_pdu *request, union ccb *ccb,
194 		    uint32_t *initiator_task_tagp);
195 static void	iscsi_outstanding_remove(struct iscsi_session *is,
196 		    struct iscsi_outstanding *io);
197 
198 static bool
199 iscsi_pdu_prepare(struct icl_pdu *request)
200 {
201 	struct iscsi_session *is;
202 	struct iscsi_bhs_scsi_command *bhssc;
203 
204 	is = PDU_SESSION(request);
205 
206 	ISCSI_SESSION_LOCK_ASSERT(is);
207 
208 	/*
209 	 * We're only using fields common for all the request
210 	 * (initiator -> target) PDUs.
211 	 */
212 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
213 
214 	/*
215 	 * Data-Out PDU does not contain CmdSN.
216 	 */
217 	if (bhssc->bhssc_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_OUT) {
218 		if (ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn) &&
219 		    (bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0) {
220 			/*
221 			 * Current MaxCmdSN prevents us from sending any more
222 			 * SCSI Command PDUs to the target; postpone the PDU.
223 			 * It will get resent by either iscsi_pdu_queue(),
224 			 * or by maintenance thread.
225 			 */
226 #if 0
227 			ISCSI_SESSION_DEBUG(is, "postponing send, CmdSN %u, "
228 			    "ExpCmdSN %u, MaxCmdSN %u, opcode 0x%x",
229 			    is->is_cmdsn, is->is_expcmdsn, is->is_maxcmdsn,
230 			    bhssc->bhssc_opcode);
231 #endif
232 			return (true);
233 		}
234 		bhssc->bhssc_cmdsn = htonl(is->is_cmdsn);
235 		if ((bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0)
236 			is->is_cmdsn++;
237 	}
238 	bhssc->bhssc_expstatsn = htonl(is->is_statsn + 1);
239 
240 	return (false);
241 }
242 
243 static void
244 iscsi_session_send_postponed(struct iscsi_session *is)
245 {
246 	struct icl_pdu *request;
247 	bool postpone;
248 
249 	ISCSI_SESSION_LOCK_ASSERT(is);
250 
251 	if (STAILQ_EMPTY(&is->is_postponed))
252 		return;
253 	while ((request = STAILQ_FIRST(&is->is_postponed)) != NULL) {
254 		postpone = iscsi_pdu_prepare(request);
255 		if (postpone)
256 			return;
257 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
258 		icl_pdu_queue(request);
259 	}
260 	xpt_release_simq(is->is_sim, 1);
261 }
262 
263 static void
264 iscsi_pdu_queue_locked(struct icl_pdu *request)
265 {
266 	struct iscsi_session *is;
267 	bool postpone;
268 
269 	is = PDU_SESSION(request);
270 	ISCSI_SESSION_LOCK_ASSERT(is);
271 	iscsi_session_send_postponed(is);
272 	postpone = iscsi_pdu_prepare(request);
273 	if (postpone) {
274 		if (STAILQ_EMPTY(&is->is_postponed))
275 			xpt_freeze_simq(is->is_sim, 1);
276 		STAILQ_INSERT_TAIL(&is->is_postponed, request, ip_next);
277 		return;
278 	}
279 	icl_pdu_queue(request);
280 }
281 
282 static void
283 iscsi_pdu_queue(struct icl_pdu *request)
284 {
285 	struct iscsi_session *is;
286 
287 	is = PDU_SESSION(request);
288 	ISCSI_SESSION_LOCK(is);
289 	iscsi_pdu_queue_locked(request);
290 	ISCSI_SESSION_UNLOCK(is);
291 }
292 
293 static void
294 iscsi_session_logout(struct iscsi_session *is)
295 {
296 	struct icl_pdu *request;
297 	struct iscsi_bhs_logout_request *bhslr;
298 
299 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
300 	if (request == NULL)
301 		return;
302 
303 	bhslr = (struct iscsi_bhs_logout_request *)request->ip_bhs;
304 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST;
305 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
306 	iscsi_pdu_queue_locked(request);
307 }
308 
309 static void
310 iscsi_session_terminate_task(struct iscsi_session *is,
311     struct iscsi_outstanding *io, cam_status status)
312 {
313 
314 	ISCSI_SESSION_LOCK_ASSERT(is);
315 
316 	if (io->io_ccb != NULL) {
317 		io->io_ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
318 		io->io_ccb->ccb_h.status |= status;
319 		if ((io->io_ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
320 			io->io_ccb->ccb_h.status |= CAM_DEV_QFRZN;
321 			xpt_freeze_devq(io->io_ccb->ccb_h.path, 1);
322 			ISCSI_SESSION_DEBUG(is, "freezing devq");
323 		}
324 		xpt_done(io->io_ccb);
325 	}
326 	iscsi_outstanding_remove(is, io);
327 }
328 
329 static void
330 iscsi_session_terminate_tasks(struct iscsi_session *is, cam_status status)
331 {
332 	struct iscsi_outstanding *io, *tmp;
333 
334 	ISCSI_SESSION_LOCK_ASSERT(is);
335 
336 	TAILQ_FOREACH_SAFE(io, &is->is_outstanding, io_next, tmp) {
337 		iscsi_session_terminate_task(is, io, status);
338 	}
339 }
340 
341 static void
342 iscsi_session_cleanup(struct iscsi_session *is, bool destroy_sim)
343 {
344 	struct icl_pdu *pdu;
345 
346 	ISCSI_SESSION_LOCK_ASSERT(is);
347 
348 	/*
349 	 * Don't queue any new PDUs.
350 	 */
351 	if (is->is_sim != NULL && is->is_simq_frozen == false) {
352 		ISCSI_SESSION_DEBUG(is, "freezing");
353 		xpt_freeze_simq(is->is_sim, 1);
354 		is->is_simq_frozen = true;
355 	}
356 
357 	/*
358 	 * Remove postponed PDUs.
359 	 */
360 	if (!STAILQ_EMPTY(&is->is_postponed))
361 		xpt_release_simq(is->is_sim, 1);
362 	while ((pdu = STAILQ_FIRST(&is->is_postponed)) != NULL) {
363 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
364 		icl_pdu_free(pdu);
365 	}
366 
367 	if (destroy_sim == false) {
368 		/*
369 		 * Terminate SCSI tasks, asking CAM to requeue them.
370 		 */
371 		iscsi_session_terminate_tasks(is, CAM_REQUEUE_REQ);
372 		return;
373 	}
374 
375 	iscsi_session_terminate_tasks(is, CAM_DEV_NOT_THERE);
376 
377 	if (is->is_sim == NULL)
378 		return;
379 
380 	ISCSI_SESSION_DEBUG(is, "deregistering SIM");
381 	xpt_async(AC_LOST_DEVICE, is->is_path, NULL);
382 
383 	if (is->is_simq_frozen) {
384 		is->is_simq_frozen = false;
385 		xpt_release_simq(is->is_sim, 1);
386 	}
387 
388 	xpt_free_path(is->is_path);
389 	is->is_path = NULL;
390 	xpt_bus_deregister(cam_sim_path(is->is_sim));
391 	cam_sim_free(is->is_sim, TRUE /*free_devq*/);
392 	is->is_sim = NULL;
393 	is->is_devq = NULL;
394 }
395 
396 static void
397 iscsi_maintenance_thread_reconnect(struct iscsi_session *is)
398 {
399 	/*
400 	 * As we will be reconnecting shortly,
401 	 * discard outstanding data immediately on
402 	 * close(), also notify peer via RST if
403 	 * any packets come in.
404 	 */
405 	struct socket *so;
406 	so = is->is_conn->ic_socket;
407 	if (so != NULL) {
408 		struct sockopt sopt;
409 		struct linger sl;
410 		sopt.sopt_dir     = SOPT_SET;
411 		sopt.sopt_level   = SOL_SOCKET;
412 		sopt.sopt_name    = SO_LINGER;
413 		sopt.sopt_val     = &sl;
414 		sopt.sopt_valsize = sizeof(sl);
415 		sl.l_onoff        = 1;	/* non-zero value enables linger option in kernel */
416 		sl.l_linger       = 0;	/* timeout interval in seconds */
417 		sosetopt(is->is_conn->ic_socket, &sopt);
418 	}
419 
420 	icl_conn_close(is->is_conn);
421 
422 	ISCSI_SESSION_LOCK(is);
423 
424 	is->is_connected = false;
425 	is->is_reconnecting = false;
426 	is->is_login_phase = false;
427 
428 #ifdef ICL_KERNEL_PROXY
429 	if (is->is_login_pdu != NULL) {
430 		icl_pdu_free(is->is_login_pdu);
431 		is->is_login_pdu = NULL;
432 	}
433 	cv_signal(&is->is_login_cv);
434 #endif
435 
436 	if (fail_on_disconnection) {
437 		ISCSI_SESSION_DEBUG(is, "connection failed, destroying devices");
438 		iscsi_session_cleanup(is, true);
439 	} else {
440 		iscsi_session_cleanup(is, false);
441 	}
442 
443 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
444 	    ("destroying session with active tasks"));
445 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
446 	    ("destroying session with postponed PDUs"));
447 
448 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
449 		ISCSI_SESSION_UNLOCK(is);
450 		return;
451 	}
452 
453 	/*
454 	 * Request immediate reconnection from iscsid(8).
455 	 */
456 	//ISCSI_SESSION_DEBUG(is, "waking up iscsid(8)");
457 	is->is_waiting_for_iscsid = true;
458 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
459 	is->is_timeout = 0;
460 	ISCSI_SESSION_UNLOCK(is);
461 	cv_signal(&is->is_softc->sc_cv);
462 }
463 
464 static void
465 iscsi_maintenance_thread_terminate(struct iscsi_session *is)
466 {
467 	struct iscsi_softc *sc;
468 
469 	sc = is->is_softc;
470 	sx_xlock(&sc->sc_lock);
471 	TAILQ_REMOVE(&sc->sc_sessions, is, is_next);
472 	sx_xunlock(&sc->sc_lock);
473 
474 	icl_conn_close(is->is_conn);
475 	callout_drain(&is->is_callout);
476 
477 	ISCSI_SESSION_LOCK(is);
478 
479 	KASSERT(is->is_terminating, ("is_terminating == false"));
480 
481 #ifdef ICL_KERNEL_PROXY
482 	if (is->is_login_pdu != NULL) {
483 		icl_pdu_free(is->is_login_pdu);
484 		is->is_login_pdu = NULL;
485 	}
486 	cv_signal(&is->is_login_cv);
487 #endif
488 
489 	iscsi_session_cleanup(is, true);
490 
491 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
492 	    ("destroying session with active tasks"));
493 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
494 	    ("destroying session with postponed PDUs"));
495 
496 	ISCSI_SESSION_UNLOCK(is);
497 
498 	icl_conn_free(is->is_conn);
499 	mtx_destroy(&is->is_lock);
500 	cv_destroy(&is->is_maintenance_cv);
501 #ifdef ICL_KERNEL_PROXY
502 	cv_destroy(&is->is_login_cv);
503 #endif
504 
505 	ISCSI_SESSION_DEBUG(is, "terminated");
506 	free(is, M_ISCSI);
507 
508 	/*
509 	 * The iscsi_unload() routine might be waiting.
510 	 */
511 	cv_signal(&sc->sc_cv);
512 }
513 
514 static void
515 iscsi_maintenance_thread(void *arg)
516 {
517 	struct iscsi_session *is = arg;
518 
519 	ISCSI_SESSION_LOCK(is);
520 	for (;;) {
521 		if (is->is_reconnecting == false &&
522 		    is->is_terminating == false &&
523 		    (STAILQ_EMPTY(&is->is_postponed) ||
524 		     ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn)))
525 			cv_wait(&is->is_maintenance_cv, &is->is_lock);
526 
527 		/* Terminate supersedes reconnect. */
528 		if (is->is_terminating) {
529 			ISCSI_SESSION_UNLOCK(is);
530 			iscsi_maintenance_thread_terminate(is);
531 			kthread_exit();
532 			return;
533 		}
534 
535 		if (is->is_reconnecting) {
536 			ISCSI_SESSION_UNLOCK(is);
537 			iscsi_maintenance_thread_reconnect(is);
538 			ISCSI_SESSION_LOCK(is);
539 			continue;
540 		}
541 
542 		iscsi_session_send_postponed(is);
543 	}
544 	ISCSI_SESSION_UNLOCK(is);
545 }
546 
547 static void
548 iscsi_session_reconnect(struct iscsi_session *is)
549 {
550 
551 	/*
552 	 * XXX: We can't use locking here, because
553 	 * 	it's being called from various contexts.
554 	 * 	Hope it doesn't break anything.
555 	 */
556 	if (is->is_reconnecting)
557 		return;
558 
559 	is->is_reconnecting = true;
560 	cv_signal(&is->is_maintenance_cv);
561 }
562 
563 static void
564 iscsi_session_terminate(struct iscsi_session *is)
565 {
566 
567 	if (is->is_terminating)
568 		return;
569 
570 	is->is_terminating = true;
571 
572 #if 0
573 	iscsi_session_logout(is);
574 #endif
575 	cv_signal(&is->is_maintenance_cv);
576 }
577 
578 static void
579 iscsi_callout(void *context)
580 {
581 	struct icl_pdu *request;
582 	struct iscsi_bhs_nop_out *bhsno;
583 	struct iscsi_session *is;
584 	bool reconnect_needed = false;
585 	sbintime_t sbt, pr;
586 
587 	is = context;
588 
589 	ISCSI_SESSION_LOCK(is);
590 	if (is->is_terminating) {
591 		ISCSI_SESSION_UNLOCK(is);
592 		return;
593 	}
594 
595 	sbt = mstosbt(995);
596 	pr  = mstosbt(10);
597 	callout_schedule_sbt(&is->is_callout, sbt, pr, 0);
598 
599 	if (is->is_conf.isc_enable == 0)
600 		goto out;
601 
602 	is->is_timeout++;
603 
604 	if (is->is_waiting_for_iscsid) {
605 		if (iscsid_timeout > 0 && is->is_timeout > iscsid_timeout) {
606 			ISCSI_SESSION_WARN(is, "timed out waiting for iscsid(8) "
607 			    "for %d seconds; reconnecting",
608 			    is->is_timeout);
609 			reconnect_needed = true;
610 		}
611 		goto out;
612 	}
613 
614 	if (is->is_login_phase) {
615 		if (is->is_login_timeout > 0 && is->is_timeout > is->is_login_timeout) {
616 			ISCSI_SESSION_WARN(is, "login timed out after %d seconds; "
617 			    "reconnecting", is->is_timeout);
618 			reconnect_needed = true;
619 		}
620 		goto out;
621 	}
622 
623 	if (is->is_ping_timeout <= 0) {
624 		/*
625 		 * Pings are disabled.  Don't send NOP-Out in this case.
626 		 * Reset the timeout, to avoid triggering reconnection,
627 		 * should the user decide to reenable them.
628 		 */
629 		is->is_timeout = 0;
630 		goto out;
631 	}
632 
633 	if (is->is_timeout >= is->is_ping_timeout) {
634 		ISCSI_SESSION_WARN(is, "no ping reply (NOP-In) after %d seconds; "
635 		    "reconnecting", is->is_ping_timeout);
636 		reconnect_needed = true;
637 		goto out;
638 	}
639 
640 	ISCSI_SESSION_UNLOCK(is);
641 
642 	/*
643 	 * If the ping was reset less than one second ago - which means
644 	 * that we've received some PDU during the last second - assume
645 	 * the traffic flows correctly and don't bother sending a NOP-Out.
646 	 *
647 	 * (It's 2 - one for one second, and one for incrementing is_timeout
648 	 * earlier in this routine.)
649 	 */
650 	if (is->is_timeout < 2)
651 		return;
652 
653 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
654 	if (request == NULL) {
655 		ISCSI_SESSION_WARN(is, "failed to allocate PDU");
656 		return;
657 	}
658 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
659 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
660 	    ISCSI_BHS_OPCODE_IMMEDIATE;
661 	bhsno->bhsno_flags = 0x80;
662 	bhsno->bhsno_target_transfer_tag = 0xffffffff;
663 	iscsi_pdu_queue(request);
664 	return;
665 
666 out:
667 	if (is->is_terminating) {
668 		ISCSI_SESSION_UNLOCK(is);
669 		return;
670 	}
671 
672 	ISCSI_SESSION_UNLOCK(is);
673 
674 	if (reconnect_needed)
675 		iscsi_session_reconnect(is);
676 }
677 
678 static void
679 iscsi_pdu_update_statsn(const struct icl_pdu *response)
680 {
681 	const struct iscsi_bhs_data_in *bhsdi;
682 	struct iscsi_session *is;
683 	uint32_t expcmdsn, maxcmdsn, statsn;
684 
685 	is = PDU_SESSION(response);
686 
687 	ISCSI_SESSION_LOCK_ASSERT(is);
688 
689 	/*
690 	 * We're only using fields common for all the response
691 	 * (target -> initiator) PDUs.
692 	 */
693 	bhsdi = (const struct iscsi_bhs_data_in *)response->ip_bhs;
694 	/*
695 	 * Ok, I lied.  In case of Data-In, "The fields StatSN, Status,
696 	 * and Residual Count only have meaningful content if the S bit
697 	 * is set to 1", so we also need to check the bit specific for
698 	 * Data-In PDU.
699 	 */
700 	if (bhsdi->bhsdi_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_IN ||
701 	    (bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0) {
702 		statsn = ntohl(bhsdi->bhsdi_statsn);
703 		if (statsn != is->is_statsn && statsn != (is->is_statsn + 1)) {
704 			/* XXX: This is normal situation for MCS */
705 			ISCSI_SESSION_WARN(is, "PDU 0x%x StatSN %u != "
706 			    "session ExpStatSN %u (or + 1); reconnecting",
707 			    bhsdi->bhsdi_opcode, statsn, is->is_statsn);
708 			iscsi_session_reconnect(is);
709 		}
710 		if (ISCSI_SNGT(statsn, is->is_statsn))
711 			is->is_statsn = statsn;
712 	}
713 
714 	expcmdsn = ntohl(bhsdi->bhsdi_expcmdsn);
715 	maxcmdsn = ntohl(bhsdi->bhsdi_maxcmdsn);
716 
717 	if (ISCSI_SNLT(maxcmdsn + 1, expcmdsn)) {
718 		ISCSI_SESSION_DEBUG(is,
719 		    "PDU MaxCmdSN %u + 1 < PDU ExpCmdSN %u; ignoring",
720 		    maxcmdsn, expcmdsn);
721 	} else {
722 		if (ISCSI_SNGT(maxcmdsn, is->is_maxcmdsn)) {
723 			is->is_maxcmdsn = maxcmdsn;
724 
725 			/*
726 			 * Command window increased; kick the maintanance thread
727 			 * to send out postponed commands.
728 			 */
729 			if (!STAILQ_EMPTY(&is->is_postponed))
730 				cv_signal(&is->is_maintenance_cv);
731 		} else if (ISCSI_SNLT(maxcmdsn, is->is_maxcmdsn)) {
732 			/* XXX: This is normal situation for MCS */
733 			ISCSI_SESSION_DEBUG(is,
734 			    "PDU MaxCmdSN %u < session MaxCmdSN %u; ignoring",
735 			    maxcmdsn, is->is_maxcmdsn);
736 		}
737 
738 		if (ISCSI_SNGT(expcmdsn, is->is_expcmdsn)) {
739 			is->is_expcmdsn = expcmdsn;
740 		} else if (ISCSI_SNLT(expcmdsn, is->is_expcmdsn)) {
741 			/* XXX: This is normal situation for MCS */
742 			ISCSI_SESSION_DEBUG(is,
743 			    "PDU ExpCmdSN %u < session ExpCmdSN %u; ignoring",
744 			    expcmdsn, is->is_expcmdsn);
745 		}
746 	}
747 
748 	/*
749 	 * Every incoming PDU - not just NOP-In - resets the ping timer.
750 	 * The purpose of the timeout is to reset the connection when it stalls;
751 	 * we don't want this to happen when NOP-In or NOP-Out ends up delayed
752 	 * in some queue.
753 	 */
754 	is->is_timeout = 0;
755 }
756 
757 static void
758 iscsi_receive_callback(struct icl_pdu *response)
759 {
760 	struct iscsi_session *is;
761 
762 	is = PDU_SESSION(response);
763 
764 	ISCSI_SESSION_LOCK(is);
765 
766 	iscsi_pdu_update_statsn(response);
767 
768 #ifdef ICL_KERNEL_PROXY
769 	if (is->is_login_phase) {
770 		if (is->is_login_pdu == NULL)
771 			is->is_login_pdu = response;
772 		else
773 			icl_pdu_free(response);
774 		ISCSI_SESSION_UNLOCK(is);
775 		cv_signal(&is->is_login_cv);
776 		return;
777 	}
778 #endif
779 
780 	/*
781 	 * The handling routine is responsible for freeing the PDU
782 	 * when it's no longer needed.
783 	 */
784 	switch (response->ip_bhs->bhs_opcode) {
785 	case ISCSI_BHS_OPCODE_NOP_IN:
786 		iscsi_pdu_handle_nop_in(response);
787 		ISCSI_SESSION_UNLOCK(is);
788 		break;
789 	case ISCSI_BHS_OPCODE_SCSI_RESPONSE:
790 		iscsi_pdu_handle_scsi_response(response);
791 		/* Session lock dropped inside. */
792 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
793 		break;
794 	case ISCSI_BHS_OPCODE_TASK_RESPONSE:
795 		iscsi_pdu_handle_task_response(response);
796 		ISCSI_SESSION_UNLOCK(is);
797 		break;
798 	case ISCSI_BHS_OPCODE_SCSI_DATA_IN:
799 		iscsi_pdu_handle_data_in(response);
800 		/* Session lock dropped inside. */
801 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
802 		break;
803 	case ISCSI_BHS_OPCODE_LOGOUT_RESPONSE:
804 		iscsi_pdu_handle_logout_response(response);
805 		ISCSI_SESSION_UNLOCK(is);
806 		break;
807 	case ISCSI_BHS_OPCODE_R2T:
808 		iscsi_pdu_handle_r2t(response);
809 		ISCSI_SESSION_UNLOCK(is);
810 		break;
811 	case ISCSI_BHS_OPCODE_ASYNC_MESSAGE:
812 		iscsi_pdu_handle_async_message(response);
813 		ISCSI_SESSION_UNLOCK(is);
814 		break;
815 	case ISCSI_BHS_OPCODE_REJECT:
816 		iscsi_pdu_handle_reject(response);
817 		ISCSI_SESSION_UNLOCK(is);
818 		break;
819 	default:
820 		ISCSI_SESSION_WARN(is, "received PDU with unsupported "
821 		    "opcode 0x%x; reconnecting",
822 		    response->ip_bhs->bhs_opcode);
823 		iscsi_session_reconnect(is);
824 		ISCSI_SESSION_UNLOCK(is);
825 		icl_pdu_free(response);
826 	}
827 }
828 
829 static void
830 iscsi_error_callback(struct icl_conn *ic)
831 {
832 	struct iscsi_session *is;
833 
834 	is = CONN_SESSION(ic);
835 
836 	ISCSI_SESSION_WARN(is, "connection error; reconnecting");
837 	iscsi_session_reconnect(is);
838 }
839 
840 static void
841 iscsi_pdu_handle_nop_in(struct icl_pdu *response)
842 {
843 	struct iscsi_session *is;
844 	struct iscsi_bhs_nop_out *bhsno;
845 	struct iscsi_bhs_nop_in *bhsni;
846 	struct icl_pdu *request;
847 	void *data = NULL;
848 	size_t datasize;
849 	int error;
850 
851 	is = PDU_SESSION(response);
852 	bhsni = (struct iscsi_bhs_nop_in *)response->ip_bhs;
853 
854 	if (bhsni->bhsni_target_transfer_tag == 0xffffffff) {
855 		/*
856 		 * Nothing to do; iscsi_pdu_update_statsn() already
857 		 * zeroed the timeout.
858 		 */
859 		icl_pdu_free(response);
860 		return;
861 	}
862 
863 	datasize = icl_pdu_data_segment_length(response);
864 	if (datasize > 0) {
865 		data = malloc(datasize, M_ISCSI, M_NOWAIT | M_ZERO);
866 		if (data == NULL) {
867 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
868 			    "reconnecting");
869 			icl_pdu_free(response);
870 			iscsi_session_reconnect(is);
871 			return;
872 		}
873 		icl_pdu_get_data(response, 0, data, datasize);
874 	}
875 
876 	request = icl_pdu_new(response->ip_conn, M_NOWAIT);
877 	if (request == NULL) {
878 		ISCSI_SESSION_WARN(is, "failed to allocate memory; "
879 		    "reconnecting");
880 		free(data, M_ISCSI);
881 		icl_pdu_free(response);
882 		iscsi_session_reconnect(is);
883 		return;
884 	}
885 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
886 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
887 	    ISCSI_BHS_OPCODE_IMMEDIATE;
888 	bhsno->bhsno_flags = 0x80;
889 	bhsno->bhsno_initiator_task_tag = 0xffffffff;
890 	bhsno->bhsno_target_transfer_tag = bhsni->bhsni_target_transfer_tag;
891 	if (datasize > 0) {
892 		error = icl_pdu_append_data(request, data, datasize, M_NOWAIT);
893 		if (error != 0) {
894 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
895 			    "reconnecting");
896 			free(data, M_ISCSI);
897 			icl_pdu_free(request);
898 			icl_pdu_free(response);
899 			iscsi_session_reconnect(is);
900 			return;
901 		}
902 		free(data, M_ISCSI);
903 	}
904 
905 	icl_pdu_free(response);
906 	iscsi_pdu_queue_locked(request);
907 }
908 
909 static void
910 iscsi_pdu_handle_scsi_response(struct icl_pdu *response)
911 {
912 	struct iscsi_bhs_scsi_response *bhssr;
913 	struct iscsi_outstanding *io;
914 	struct iscsi_session *is;
915 	union ccb *ccb;
916 	struct ccb_scsiio *csio;
917 	size_t data_segment_len, received;
918 	uint16_t sense_len;
919 	uint32_t resid;
920 
921 	is = PDU_SESSION(response);
922 
923 	bhssr = (struct iscsi_bhs_scsi_response *)response->ip_bhs;
924 	io = iscsi_outstanding_find(is, bhssr->bhssr_initiator_task_tag);
925 	if (io == NULL || io->io_ccb == NULL) {
926 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhssr->bhssr_initiator_task_tag);
927 		icl_pdu_free(response);
928 		iscsi_session_reconnect(is);
929 		ISCSI_SESSION_UNLOCK(is);
930 		return;
931 	}
932 
933 	ccb = io->io_ccb;
934 	if (bhssr->bhssr_response == BHSSR_RESPONSE_COMMAND_COMPLETED) {
935 		if (ntohl(bhssr->bhssr_expdatasn) != io->io_datasn) {
936 			ISCSI_SESSION_WARN(is,
937 			    "ExpDataSN mismatch in SCSI Response (%u vs %u)",
938 			    ntohl(bhssr->bhssr_expdatasn), io->io_datasn);
939 
940 			/*
941 			 * XXX: Permit an ExpDataSN of zero for errors.
942 			 *
943 			 * This doesn't conform to RFC 7143, but some
944 			 * targets seem to do this.
945 			 */
946 			if (bhssr->bhssr_status != 0 &&
947 			    bhssr->bhssr_expdatasn == htonl(0))
948 				goto skip_expdatasn;
949 
950 			icl_pdu_free(response);
951 			iscsi_session_reconnect(is);
952 			ISCSI_SESSION_UNLOCK(is);
953 			return;
954 		}
955 	} else {
956 		if (bhssr->bhssr_expdatasn != htonl(0)) {
957 			ISCSI_SESSION_WARN(is,
958 			    "ExpDataSN mismatch in SCSI Response (%u vs 0)",
959 			    ntohl(bhssr->bhssr_expdatasn));
960 			icl_pdu_free(response);
961 			iscsi_session_reconnect(is);
962 			ISCSI_SESSION_UNLOCK(is);
963 			return;
964 		}
965 	}
966 skip_expdatasn:
967 
968 	/*
969 	 * With iSER, after getting good response we can be sure
970 	 * that all the data has been successfully transferred.
971 	 */
972 	if (is->is_conn->ic_iser) {
973 		resid = ntohl(bhssr->bhssr_residual_count);
974 		if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW) {
975 			io->io_received = ccb->csio.dxfer_len - resid;
976 		} else if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_OVERFLOW) {
977 			ISCSI_SESSION_WARN(is, "overflow: target indicates %d", resid);
978 		} else {
979 			io->io_received = ccb->csio.dxfer_len;
980 		}
981 	}
982 
983 	received = io->io_received;
984 	iscsi_outstanding_remove(is, io);
985 	ISCSI_SESSION_UNLOCK(is);
986 
987 	if (bhssr->bhssr_response != BHSSR_RESPONSE_COMMAND_COMPLETED) {
988 		ISCSI_SESSION_WARN(is, "service response 0x%x", bhssr->bhssr_response);
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 	} else if (bhssr->bhssr_status == 0) {
995 		ccb->ccb_h.status = CAM_REQ_CMP;
996 	} else {
997  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
998  			xpt_freeze_devq(ccb->ccb_h.path, 1);
999 			ISCSI_SESSION_DEBUG(is, "freezing devq");
1000 		}
1001  		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
1002 		ccb->csio.scsi_status = bhssr->bhssr_status;
1003 	}
1004 
1005 	csio = &ccb->csio;
1006 	data_segment_len = icl_pdu_data_segment_length(response);
1007 	if (data_segment_len > 0) {
1008 		if (data_segment_len < sizeof(sense_len)) {
1009 			ISCSI_SESSION_WARN(is, "truncated data segment (%zd bytes)",
1010 			    data_segment_len);
1011 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
1012 				xpt_freeze_devq(ccb->ccb_h.path, 1);
1013 				ISCSI_SESSION_DEBUG(is, "freezing devq");
1014 			}
1015 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
1016 			goto out;
1017 		}
1018 		icl_pdu_get_data(response, 0, &sense_len, sizeof(sense_len));
1019 		sense_len = ntohs(sense_len);
1020 #if 0
1021 		ISCSI_SESSION_DEBUG(is, "sense_len %d, data len %zd",
1022 		    sense_len, data_segment_len);
1023 #endif
1024 		if (sizeof(sense_len) + sense_len > data_segment_len) {
1025 			ISCSI_SESSION_WARN(is, "truncated data segment "
1026 			    "(%zd bytes, should be %zd)",
1027 			    data_segment_len, sizeof(sense_len) + sense_len);
1028 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
1029 				xpt_freeze_devq(ccb->ccb_h.path, 1);
1030 				ISCSI_SESSION_DEBUG(is, "freezing devq");
1031 			}
1032 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
1033 			goto out;
1034 		} else if (sizeof(sense_len) + sense_len < data_segment_len)
1035 			ISCSI_SESSION_WARN(is, "oversize data segment "
1036 			    "(%zd bytes, should be %zd)",
1037 			    data_segment_len, sizeof(sense_len) + sense_len);
1038 		if (sense_len > csio->sense_len) {
1039 			ISCSI_SESSION_DEBUG(is, "truncating sense from %d to %d",
1040 			    sense_len, csio->sense_len);
1041 			sense_len = csio->sense_len;
1042 		}
1043 		icl_pdu_get_data(response, sizeof(sense_len), &csio->sense_data, sense_len);
1044 		csio->sense_resid = csio->sense_len - sense_len;
1045 		ccb->ccb_h.status |= CAM_AUTOSNS_VALID;
1046 	}
1047 
1048 out:
1049 	if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW)
1050 		csio->resid = ntohl(bhssr->bhssr_residual_count);
1051 
1052 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
1053 		KASSERT(received <= csio->dxfer_len,
1054 		    ("received > csio->dxfer_len"));
1055 		if (received < csio->dxfer_len) {
1056 			if (csio->resid != csio->dxfer_len - received) {
1057 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
1058 				    "target indicates %d, we calculated %zd",
1059 				    csio->resid, csio->dxfer_len - received);
1060 			}
1061 			csio->resid = csio->dxfer_len - received;
1062 		}
1063 	}
1064 
1065 	xpt_done(ccb);
1066 	icl_pdu_free(response);
1067 }
1068 
1069 static void
1070 iscsi_pdu_handle_task_response(struct icl_pdu *response)
1071 {
1072 	struct iscsi_bhs_task_management_response *bhstmr;
1073 	struct iscsi_outstanding *io, *aio;
1074 	struct iscsi_session *is;
1075 
1076 	is = PDU_SESSION(response);
1077 
1078 	bhstmr = (struct iscsi_bhs_task_management_response *)response->ip_bhs;
1079 	io = iscsi_outstanding_find(is, bhstmr->bhstmr_initiator_task_tag);
1080 	if (io == NULL || io->io_ccb != NULL) {
1081 		ISCSI_SESSION_WARN(is, "bad itt 0x%x",
1082 		    bhstmr->bhstmr_initiator_task_tag);
1083 		icl_pdu_free(response);
1084 		iscsi_session_reconnect(is);
1085 		return;
1086 	}
1087 
1088 	if (bhstmr->bhstmr_response != BHSTMR_RESPONSE_FUNCTION_COMPLETE) {
1089 		ISCSI_SESSION_WARN(is, "task response 0x%x",
1090 		    bhstmr->bhstmr_response);
1091 	} else {
1092 		aio = iscsi_outstanding_find(is, io->io_referenced_task_tag);
1093 		if (aio != NULL && aio->io_ccb != NULL)
1094 			iscsi_session_terminate_task(is, aio, CAM_REQ_ABORTED);
1095 	}
1096 
1097 	iscsi_outstanding_remove(is, io);
1098 	icl_pdu_free(response);
1099 }
1100 
1101 static void
1102 iscsi_pdu_get_data_csio(struct icl_pdu *response, size_t pdu_offset,
1103     struct ccb_scsiio *csio, size_t oreceived, size_t data_segment_len)
1104 {
1105 	switch (csio->ccb_h.flags & CAM_DATA_MASK) {
1106 	case CAM_DATA_BIO:
1107 		icl_pdu_get_bio(response, pdu_offset,
1108 		    (struct bio *)csio->data_ptr, oreceived, data_segment_len);
1109 		break;
1110 	case CAM_DATA_VADDR:
1111 		icl_pdu_get_data(response, pdu_offset,
1112 		    csio->data_ptr + oreceived, data_segment_len);
1113 		break;
1114 	default:
1115 		__assert_unreachable();
1116 	}
1117 }
1118 
1119 static void
1120 iscsi_pdu_handle_data_in(struct icl_pdu *response)
1121 {
1122 	struct iscsi_bhs_data_in *bhsdi;
1123 	struct iscsi_outstanding *io;
1124 	struct iscsi_session *is;
1125 	union ccb *ccb;
1126 	struct ccb_scsiio *csio;
1127 	size_t data_segment_len, received, oreceived;
1128 
1129 	is = PDU_SESSION(response);
1130 	bhsdi = (struct iscsi_bhs_data_in *)response->ip_bhs;
1131 	io = iscsi_outstanding_find(is, bhsdi->bhsdi_initiator_task_tag);
1132 	if (io == NULL || io->io_ccb == NULL) {
1133 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhsdi->bhsdi_initiator_task_tag);
1134 		icl_pdu_free(response);
1135 		iscsi_session_reconnect(is);
1136 		ISCSI_SESSION_UNLOCK(is);
1137 		return;
1138 	}
1139 
1140 	if (io->io_datasn != ntohl(bhsdi->bhsdi_datasn)) {
1141 		ISCSI_SESSION_WARN(is, "received Data-In PDU with "
1142 		    "DataSN %u, while expected %u; dropping connection",
1143 		    ntohl(bhsdi->bhsdi_datasn), io->io_datasn);
1144 		icl_pdu_free(response);
1145 		iscsi_session_reconnect(is);
1146 		ISCSI_SESSION_UNLOCK(is);
1147 		return;
1148 	}
1149 	io->io_datasn += response->ip_additional_pdus + 1;
1150 
1151 	data_segment_len = icl_pdu_data_segment_length(response);
1152 	if (data_segment_len == 0) {
1153 		/*
1154 		 * "The sending of 0 length data segments should be avoided,
1155 		 * but initiators and targets MUST be able to properly receive
1156 		 * 0 length data segments."
1157 		 */
1158 		ISCSI_SESSION_UNLOCK(is);
1159 		icl_pdu_free(response);
1160 		return;
1161 	}
1162 
1163 	/*
1164 	 * We need to track this for security reasons - without it, malicious target
1165 	 * could respond to SCSI READ without sending Data-In PDUs, which would result
1166 	 * in read operation on the initiator side returning random kernel data.
1167 	 */
1168 	if (ntohl(bhsdi->bhsdi_buffer_offset) != io->io_received) {
1169 		ISCSI_SESSION_WARN(is, "data out of order; expected offset %zd, got %zd",
1170 		    io->io_received, (size_t)ntohl(bhsdi->bhsdi_buffer_offset));
1171 		icl_pdu_free(response);
1172 		iscsi_session_reconnect(is);
1173 		ISCSI_SESSION_UNLOCK(is);
1174 		return;
1175 	}
1176 
1177 	ccb = io->io_ccb;
1178 	csio = &ccb->csio;
1179 
1180 	if (io->io_received + data_segment_len > csio->dxfer_len) {
1181 		ISCSI_SESSION_WARN(is, "oversize data segment (%zd bytes "
1182 		    "at offset %zd, buffer is %d)",
1183 		    data_segment_len, io->io_received, csio->dxfer_len);
1184 		icl_pdu_free(response);
1185 		iscsi_session_reconnect(is);
1186 		ISCSI_SESSION_UNLOCK(is);
1187 		return;
1188 	}
1189 
1190 	oreceived = io->io_received;
1191 	io->io_received += data_segment_len;
1192 	received = io->io_received;
1193 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0)
1194 		iscsi_outstanding_remove(is, io);
1195 	ISCSI_SESSION_UNLOCK(is);
1196 
1197 	iscsi_pdu_get_data_csio(response, 0, csio, oreceived, data_segment_len);
1198 
1199 	/*
1200 	 * XXX: Check F.
1201 	 */
1202 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) == 0) {
1203 		/*
1204 		 * Nothing more to do.
1205 		 */
1206 		icl_pdu_free(response);
1207 		return;
1208 	}
1209 
1210 	//ISCSI_SESSION_DEBUG(is, "got S flag; status 0x%x", bhsdi->bhsdi_status);
1211 	if (bhsdi->bhsdi_status == 0) {
1212 		ccb->ccb_h.status = CAM_REQ_CMP;
1213 	} else {
1214 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
1215 			xpt_freeze_devq(ccb->ccb_h.path, 1);
1216 			ISCSI_SESSION_DEBUG(is, "freezing devq");
1217 		}
1218 		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
1219 		csio->scsi_status = bhsdi->bhsdi_status;
1220 	}
1221 
1222 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
1223 		KASSERT(received <= csio->dxfer_len,
1224 		    ("received > csio->dxfer_len"));
1225 		if (received < csio->dxfer_len) {
1226 			csio->resid = ntohl(bhsdi->bhsdi_residual_count);
1227 			if (csio->resid != csio->dxfer_len - received) {
1228 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
1229 				    "target indicates %d, we calculated %zd",
1230 				    csio->resid, csio->dxfer_len - received);
1231 			}
1232 			csio->resid = csio->dxfer_len - received;
1233 		}
1234 	}
1235 
1236 	xpt_done(ccb);
1237 	icl_pdu_free(response);
1238 }
1239 
1240 static void
1241 iscsi_pdu_handle_logout_response(struct icl_pdu *response)
1242 {
1243 
1244 	ISCSI_SESSION_DEBUG(PDU_SESSION(response), "logout response");
1245 	icl_pdu_free(response);
1246 }
1247 
1248 static int
1249 iscsi_pdu_append_data_csio(struct icl_pdu *request, struct ccb_scsiio *csio,
1250     size_t off, size_t len, int how)
1251 {
1252 	switch (csio->ccb_h.flags & CAM_DATA_MASK) {
1253 	case CAM_DATA_BIO:
1254 		return (icl_pdu_append_bio(request,
1255 			(struct bio *)csio->data_ptr, off, len, how));
1256 	case CAM_DATA_VADDR:
1257 		return (icl_pdu_append_data(request, csio->data_ptr + off, len,
1258 		    how));
1259 	default:
1260 		__assert_unreachable();
1261 	}
1262 }
1263 
1264 static void
1265 iscsi_pdu_handle_r2t(struct icl_pdu *response)
1266 {
1267 	struct icl_pdu *request;
1268 	struct iscsi_session *is;
1269 	struct iscsi_bhs_r2t *bhsr2t;
1270 	struct iscsi_bhs_data_out *bhsdo;
1271 	struct iscsi_outstanding *io;
1272 	struct ccb_scsiio *csio;
1273 	size_t off, len, max_send_data_segment_length, total_len;
1274 	int error;
1275 	uint32_t datasn = 0;
1276 
1277 	is = PDU_SESSION(response);
1278 
1279 	bhsr2t = (struct iscsi_bhs_r2t *)response->ip_bhs;
1280 	io = iscsi_outstanding_find(is, bhsr2t->bhsr2t_initiator_task_tag);
1281 	if (io == NULL || io->io_ccb == NULL) {
1282 		ISCSI_SESSION_WARN(is, "bad itt 0x%x; reconnecting",
1283 		    bhsr2t->bhsr2t_initiator_task_tag);
1284 		icl_pdu_free(response);
1285 		iscsi_session_reconnect(is);
1286 		return;
1287 	}
1288 
1289 	csio = &io->io_ccb->csio;
1290 
1291 	if ((csio->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_OUT) {
1292 		ISCSI_SESSION_WARN(is, "received R2T for read command; reconnecting");
1293 		icl_pdu_free(response);
1294 		iscsi_session_reconnect(is);
1295 		return;
1296 	}
1297 
1298 	/*
1299 	 * XXX: Verify R2TSN.
1300 	 */
1301 
1302 	off = ntohl(bhsr2t->bhsr2t_buffer_offset);
1303 	if (off > csio->dxfer_len) {
1304 		ISCSI_SESSION_WARN(is, "target requested invalid offset "
1305 		    "%zd, buffer is %d; reconnecting", off, csio->dxfer_len);
1306 		icl_pdu_free(response);
1307 		iscsi_session_reconnect(is);
1308 		return;
1309 	}
1310 
1311 	total_len = ntohl(bhsr2t->bhsr2t_desired_data_transfer_length);
1312 	if (total_len == 0 || total_len > csio->dxfer_len) {
1313 		ISCSI_SESSION_WARN(is, "target requested invalid length "
1314 		    "%zd, buffer is %d; reconnecting", total_len, csio->dxfer_len);
1315 		icl_pdu_free(response);
1316 		iscsi_session_reconnect(is);
1317 		return;
1318 	}
1319 
1320 	//ISCSI_SESSION_DEBUG(is, "r2t; off %zd, len %zd", off, total_len);
1321 
1322 	if (is->is_conn->ic_hw_isomax != 0)
1323 		max_send_data_segment_length = is->is_conn->ic_hw_isomax;
1324 	else
1325 		max_send_data_segment_length =
1326 		    is->is_conn->ic_max_send_data_segment_length;
1327 	for (;;) {
1328 		len = total_len;
1329 
1330 		if (len > max_send_data_segment_length)
1331 			len = max_send_data_segment_length;
1332 
1333 		if (off + len > csio->dxfer_len) {
1334 			ISCSI_SESSION_WARN(is, "target requested invalid "
1335 			    "length/offset %zd, buffer is %d; reconnecting",
1336 			    off + len, csio->dxfer_len);
1337 			icl_pdu_free(response);
1338 			iscsi_session_reconnect(is);
1339 			return;
1340 		}
1341 
1342 		request = icl_pdu_new(response->ip_conn, M_NOWAIT);
1343 		if (request == NULL) {
1344 			icl_pdu_free(response);
1345 			iscsi_session_reconnect(is);
1346 			return;
1347 		}
1348 
1349 		bhsdo = (struct iscsi_bhs_data_out *)request->ip_bhs;
1350 		bhsdo->bhsdo_opcode = ISCSI_BHS_OPCODE_SCSI_DATA_OUT;
1351 		bhsdo->bhsdo_lun = bhsr2t->bhsr2t_lun;
1352 		bhsdo->bhsdo_initiator_task_tag =
1353 		    bhsr2t->bhsr2t_initiator_task_tag;
1354 		bhsdo->bhsdo_target_transfer_tag =
1355 		    bhsr2t->bhsr2t_target_transfer_tag;
1356 		bhsdo->bhsdo_datasn = htonl(datasn);
1357 		bhsdo->bhsdo_buffer_offset = htonl(off);
1358 		error = iscsi_pdu_append_data_csio(request, csio, off, len,
1359 		    M_NOWAIT | ICL_NOCOPY);
1360 		if (error != 0) {
1361 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
1362 			    "reconnecting");
1363 			icl_pdu_free(request);
1364 			icl_pdu_free(response);
1365 			iscsi_session_reconnect(is);
1366 			return;
1367 		}
1368 
1369 		datasn += howmany(len,
1370 		    is->is_conn->ic_max_send_data_segment_length);
1371 		off += len;
1372 		total_len -= len;
1373 
1374 		if (total_len == 0) {
1375 			bhsdo->bhsdo_flags |= BHSDO_FLAGS_F;
1376 			//ISCSI_SESSION_DEBUG(is, "setting F, off %zd", off);
1377 		} else {
1378 			//ISCSI_SESSION_DEBUG(is, "not finished, off %zd", off);
1379 		}
1380 
1381 		iscsi_pdu_queue_locked(request);
1382 
1383 		if (total_len == 0)
1384 			break;
1385 	}
1386 
1387 	icl_pdu_free(response);
1388 }
1389 
1390 static void
1391 iscsi_pdu_handle_async_message(struct icl_pdu *response)
1392 {
1393 	struct iscsi_bhs_asynchronous_message *bhsam;
1394 	struct iscsi_session *is;
1395 
1396 	is = PDU_SESSION(response);
1397 	bhsam = (struct iscsi_bhs_asynchronous_message *)response->ip_bhs;
1398 	switch (bhsam->bhsam_async_event) {
1399 	case BHSAM_EVENT_TARGET_REQUESTS_LOGOUT:
1400 		ISCSI_SESSION_WARN(is, "target requests logout; removing session");
1401 		iscsi_session_logout(is);
1402 		iscsi_session_terminate(is);
1403 		break;
1404 	case BHSAM_EVENT_TARGET_TERMINATES_CONNECTION:
1405 		ISCSI_SESSION_WARN(is, "target indicates it will drop the connection");
1406 		break;
1407 	case BHSAM_EVENT_TARGET_TERMINATES_SESSION:
1408 		ISCSI_SESSION_WARN(is, "target indicates it will drop the session");
1409 		break;
1410 	default:
1411 		/*
1412 		 * XXX: Technically, we're obligated to also handle
1413 		 * 	parameter renegotiation.
1414 		 */
1415 		ISCSI_SESSION_WARN(is, "ignoring AsyncEvent %d", bhsam->bhsam_async_event);
1416 		break;
1417 	}
1418 
1419 	icl_pdu_free(response);
1420 }
1421 
1422 static void
1423 iscsi_pdu_handle_reject(struct icl_pdu *response)
1424 {
1425 	struct iscsi_bhs_reject *bhsr;
1426 	struct iscsi_session *is;
1427 
1428 	is = PDU_SESSION(response);
1429 	bhsr = (struct iscsi_bhs_reject *)response->ip_bhs;
1430 	ISCSI_SESSION_WARN(is, "received Reject PDU, reason 0x%x; protocol error?",
1431 	    bhsr->bhsr_reason);
1432 
1433 	icl_pdu_free(response);
1434 }
1435 
1436 static int
1437 iscsi_ioctl_daemon_wait(struct iscsi_softc *sc,
1438     struct iscsi_daemon_request *request, bool freebsd13)
1439 {
1440 	struct iscsi_session *is;
1441 	int error;
1442 
1443 	sx_slock(&sc->sc_lock);
1444 	for (;;) {
1445 		TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1446 			ISCSI_SESSION_LOCK(is);
1447 			if (is->is_conf.isc_enable == 0 &&
1448 			    is->is_conf.isc_discovery == 0) {
1449 				ISCSI_SESSION_UNLOCK(is);
1450 				continue;
1451 			}
1452 			if (is->is_waiting_for_iscsid)
1453 				break;
1454 			ISCSI_SESSION_UNLOCK(is);
1455 		}
1456 
1457 		if (is == NULL) {
1458 			if (sc->sc_unloading) {
1459 				sx_sunlock(&sc->sc_lock);
1460 				return (ENXIO);
1461 			}
1462 
1463 			/*
1464 			 * No session requires attention from iscsid(8); wait.
1465 			 */
1466 			error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
1467 			if (error != 0) {
1468 				sx_sunlock(&sc->sc_lock);
1469 				return (error);
1470 			}
1471 			continue;
1472 		}
1473 
1474 		is->is_waiting_for_iscsid = false;
1475 		is->is_login_phase = true;
1476 		is->is_reason[0] = '\0';
1477 		ISCSI_SESSION_UNLOCK(is);
1478 
1479 		request->idr_session_id = is->is_id;
1480 		memcpy(&request->idr_isid, &is->is_isid,
1481 		    sizeof(request->idr_isid));
1482 		request->idr_tsih = 0;	/* New or reinstated session. */
1483 		memcpy(&request->idr_conf, &is->is_conf,
1484 		    sizeof(request->idr_conf));
1485 
1486 #ifdef COMPAT_FREEBSD13
1487 		if (freebsd13) {
1488 			struct icl_drv_limits idl;
1489 			struct iscsi_daemon_request13 *request13;
1490 
1491 			error = icl_limits(is->is_conf.isc_offload,
1492 			    is->is_conf.isc_iser, 0, &idl);
1493 			if (error != 0) {
1494 				ISCSI_SESSION_WARN(is, "icl_limits for "
1495 				    "offload \"%s\" failed with error %d",
1496 				    is->is_conf.isc_offload, error);
1497 				sx_sunlock(&sc->sc_lock);
1498 				return (error);
1499 			}
1500 			request13 = (struct iscsi_daemon_request13 *)request;
1501 			request13->idr_limits.isl_max_recv_data_segment_length =
1502 			    idl.idl_max_recv_data_segment_length;
1503 			request13->idr_limits.isl_max_send_data_segment_length =
1504 			    idl.idl_max_send_data_segment_length;
1505 			request13->idr_limits.isl_max_burst_length =
1506 			    idl.idl_max_burst_length;
1507 			request13->idr_limits.isl_first_burst_length =
1508 			    idl.idl_first_burst_length;
1509 		}
1510 #endif
1511 		sx_sunlock(&sc->sc_lock);
1512 		return (0);
1513 	}
1514 }
1515 
1516 static int
1517 iscsi_ioctl_daemon_limits(struct iscsi_softc *sc,
1518     struct iscsi_daemon_limits *limits)
1519 {
1520 	struct icl_drv_limits idl;
1521 	struct iscsi_session *is;
1522 	int error;
1523 
1524 	sx_slock(&sc->sc_lock);
1525 
1526 	/*
1527 	 * Find the session to fetch limits for.
1528 	 */
1529 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1530 		if (is->is_id == limits->idl_session_id)
1531 			break;
1532 	}
1533 	if (is == NULL) {
1534 		sx_sunlock(&sc->sc_lock);
1535 		return (ESRCH);
1536 	}
1537 
1538 	error = icl_limits(is->is_conf.isc_offload, is->is_conf.isc_iser,
1539 	    limits->idl_socket, &idl);
1540 	sx_sunlock(&sc->sc_lock);
1541 	if (error != 0) {
1542 		ISCSI_SESSION_WARN(is, "icl_limits for offload \"%s\" "
1543 		    "failed with error %d", is->is_conf.isc_offload, error);
1544 		return (error);
1545 	}
1546 	limits->idl_limits.isl_max_recv_data_segment_length =
1547 	    idl.idl_max_recv_data_segment_length;
1548 	limits->idl_limits.isl_max_send_data_segment_length =
1549 	    idl.idl_max_send_data_segment_length;
1550 	limits->idl_limits.isl_max_burst_length =
1551 	    idl.idl_max_burst_length;
1552 	limits->idl_limits.isl_first_burst_length =
1553 	    idl.idl_first_burst_length;
1554 
1555 	return (0);
1556 }
1557 
1558 static int
1559 iscsi_ioctl_daemon_handoff(struct iscsi_softc *sc,
1560     struct iscsi_daemon_handoff *handoff)
1561 {
1562 	struct iscsi_session *is;
1563 	struct icl_conn *ic;
1564 	int error;
1565 
1566 	sx_slock(&sc->sc_lock);
1567 
1568 	/*
1569 	 * Find the session to hand off socket to.
1570 	 */
1571 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1572 		if (is->is_id == handoff->idh_session_id)
1573 			break;
1574 	}
1575 	if (is == NULL) {
1576 		sx_sunlock(&sc->sc_lock);
1577 		return (ESRCH);
1578 	}
1579 	ISCSI_SESSION_LOCK(is);
1580 	ic = is->is_conn;
1581 	if (is->is_conf.isc_discovery || is->is_terminating) {
1582 		ISCSI_SESSION_UNLOCK(is);
1583 		sx_sunlock(&sc->sc_lock);
1584 		return (EINVAL);
1585 	}
1586 	if (is->is_connected) {
1587 		/*
1588 		 * This might have happened because another iscsid(8)
1589 		 * instance handed off the connection in the meantime.
1590 		 * Just return.
1591 		 */
1592 		ISCSI_SESSION_WARN(is, "handoff on already connected "
1593 		    "session");
1594 		ISCSI_SESSION_UNLOCK(is);
1595 		sx_sunlock(&sc->sc_lock);
1596 		return (EBUSY);
1597 	}
1598 
1599 	strlcpy(is->is_target_alias, handoff->idh_target_alias,
1600 	    sizeof(is->is_target_alias));
1601 	is->is_tsih = handoff->idh_tsih;
1602 	is->is_statsn = handoff->idh_statsn;
1603 	is->is_protocol_level = handoff->idh_protocol_level;
1604 	is->is_initial_r2t = handoff->idh_initial_r2t;
1605 	is->is_immediate_data = handoff->idh_immediate_data;
1606 
1607 	ic->ic_max_recv_data_segment_length =
1608 	    handoff->idh_max_recv_data_segment_length;
1609 	ic->ic_max_send_data_segment_length =
1610 	    handoff->idh_max_send_data_segment_length;
1611 	is->is_max_burst_length = handoff->idh_max_burst_length;
1612 	is->is_first_burst_length = handoff->idh_first_burst_length;
1613 
1614 	if (handoff->idh_header_digest == ISCSI_DIGEST_CRC32C)
1615 		ic->ic_header_crc32c = true;
1616 	else
1617 		ic->ic_header_crc32c = false;
1618 	if (handoff->idh_data_digest == ISCSI_DIGEST_CRC32C)
1619 		ic->ic_data_crc32c = true;
1620 	else
1621 		ic->ic_data_crc32c = false;
1622 	ic->ic_maxtags = maxtags;
1623 
1624 	is->is_cmdsn = 0;
1625 	is->is_expcmdsn = 0;
1626 	is->is_maxcmdsn = 0;
1627 	is->is_waiting_for_iscsid = false;
1628 	is->is_login_phase = false;
1629 	is->is_timeout = 0;
1630 	is->is_ping_timeout = is->is_conf.isc_ping_timeout;
1631 	if (is->is_ping_timeout < 0)
1632 		is->is_ping_timeout = ping_timeout;
1633 	is->is_login_timeout = is->is_conf.isc_login_timeout;
1634 	if (is->is_login_timeout < 0)
1635 		is->is_login_timeout = login_timeout;
1636 	is->is_connected = true;
1637 	is->is_reason[0] = '\0';
1638 
1639 	ISCSI_SESSION_UNLOCK(is);
1640 
1641 	/*
1642 	 * If we're going through the proxy, the idh_socket will be 0,
1643 	 * and the ICL module can simply ignore this call.  It can also
1644 	 * use it to determine it's no longer in the Login phase.
1645 	 */
1646 	error = icl_conn_handoff(ic, handoff->idh_socket);
1647 	if (error != 0) {
1648 		sx_sunlock(&sc->sc_lock);
1649 		iscsi_session_terminate(is);
1650 		return (error);
1651 	}
1652 
1653 	sx_sunlock(&sc->sc_lock);
1654 
1655 	if (is->is_sim != NULL) {
1656 		/*
1657 		 * When reconnecting, there already is SIM allocated for the session.
1658 		 */
1659 		KASSERT(is->is_simq_frozen, ("reconnect without frozen simq"));
1660 		ISCSI_SESSION_LOCK(is);
1661 		ISCSI_SESSION_DEBUG(is, "releasing");
1662 		is->is_simq_frozen = false;
1663 		xpt_release_simq(is->is_sim, 1);
1664 		ISCSI_SESSION_UNLOCK(is);
1665 
1666 	} else {
1667 		ISCSI_SESSION_LOCK(is);
1668 		is->is_devq = cam_simq_alloc(ic->ic_maxtags);
1669 		if (is->is_devq == NULL) {
1670 			ISCSI_SESSION_UNLOCK(is);
1671 			ISCSI_SESSION_WARN(is, "failed to allocate simq");
1672 			iscsi_session_terminate(is);
1673 			return (ENOMEM);
1674 		}
1675 
1676 		is->is_sim = cam_sim_alloc(iscsi_action, NULL, "iscsi",
1677 		    is, is->is_id /* unit */, &is->is_lock,
1678 		    1, ic->ic_maxtags, is->is_devq);
1679 		if (is->is_sim == NULL) {
1680 			ISCSI_SESSION_UNLOCK(is);
1681 			ISCSI_SESSION_WARN(is, "failed to allocate SIM");
1682 			cam_simq_free(is->is_devq);
1683 			iscsi_session_terminate(is);
1684 			return (ENOMEM);
1685 		}
1686 
1687 		if (xpt_bus_register(is->is_sim, NULL, 0) != 0) {
1688 			ISCSI_SESSION_UNLOCK(is);
1689 			ISCSI_SESSION_WARN(is, "failed to register bus");
1690 			iscsi_session_terminate(is);
1691 			return (ENOMEM);
1692 		}
1693 
1694 		error = xpt_create_path(&is->is_path, /*periph*/NULL,
1695 		    cam_sim_path(is->is_sim), CAM_TARGET_WILDCARD,
1696 		    CAM_LUN_WILDCARD);
1697 		if (error != CAM_REQ_CMP) {
1698 			ISCSI_SESSION_UNLOCK(is);
1699 			ISCSI_SESSION_WARN(is, "failed to create path");
1700 			iscsi_session_terminate(is);
1701 			return (ENOMEM);
1702 		}
1703 		ISCSI_SESSION_UNLOCK(is);
1704 	}
1705 
1706 	return (0);
1707 }
1708 
1709 static int
1710 iscsi_ioctl_daemon_fail(struct iscsi_softc *sc,
1711     struct iscsi_daemon_fail *fail)
1712 {
1713 	struct iscsi_session *is;
1714 
1715 	sx_slock(&sc->sc_lock);
1716 
1717 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1718 		if (is->is_id == fail->idf_session_id)
1719 			break;
1720 	}
1721 	if (is == NULL) {
1722 		sx_sunlock(&sc->sc_lock);
1723 		return (ESRCH);
1724 	}
1725 	ISCSI_SESSION_LOCK(is);
1726 	ISCSI_SESSION_DEBUG(is, "iscsid(8) failed: %s",
1727 	    fail->idf_reason);
1728 	strlcpy(is->is_reason, fail->idf_reason, sizeof(is->is_reason));
1729 	//is->is_waiting_for_iscsid = false;
1730 	//is->is_login_phase = true;
1731 	//iscsi_session_reconnect(is);
1732 	ISCSI_SESSION_UNLOCK(is);
1733 	sx_sunlock(&sc->sc_lock);
1734 
1735 	return (0);
1736 }
1737 
1738 #ifdef ICL_KERNEL_PROXY
1739 static int
1740 iscsi_ioctl_daemon_connect(struct iscsi_softc *sc,
1741     struct iscsi_daemon_connect *idc)
1742 {
1743 	struct iscsi_session *is;
1744 	struct sockaddr *from_sa, *to_sa;
1745 	int error;
1746 
1747 	sx_slock(&sc->sc_lock);
1748 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1749 		if (is->is_id == idc->idc_session_id)
1750 			break;
1751 	}
1752 	if (is == NULL) {
1753 		sx_sunlock(&sc->sc_lock);
1754 		return (ESRCH);
1755 	}
1756 	sx_sunlock(&sc->sc_lock);
1757 
1758 	if (idc->idc_from_addrlen > 0) {
1759 		error = getsockaddr(&from_sa, (void *)idc->idc_from_addr, idc->idc_from_addrlen);
1760 		if (error != 0) {
1761 			ISCSI_SESSION_WARN(is,
1762 			    "getsockaddr failed with error %d", error);
1763 			return (error);
1764 		}
1765 	} else {
1766 		from_sa = NULL;
1767 	}
1768 	error = getsockaddr(&to_sa, (void *)idc->idc_to_addr, idc->idc_to_addrlen);
1769 	if (error != 0) {
1770 		ISCSI_SESSION_WARN(is, "getsockaddr failed with error %d",
1771 		    error);
1772 		free(from_sa, M_SONAME);
1773 		return (error);
1774 	}
1775 
1776 	ISCSI_SESSION_LOCK(is);
1777 	is->is_statsn = 0;
1778 	is->is_cmdsn = 0;
1779 	is->is_expcmdsn = 0;
1780 	is->is_maxcmdsn = 0;
1781 	is->is_waiting_for_iscsid = false;
1782 	is->is_login_phase = true;
1783 	is->is_timeout = 0;
1784 	ISCSI_SESSION_UNLOCK(is);
1785 
1786 	error = icl_conn_connect(is->is_conn, idc->idc_domain,
1787 	    idc->idc_socktype, idc->idc_protocol, from_sa, to_sa);
1788 	free(from_sa, M_SONAME);
1789 	free(to_sa, M_SONAME);
1790 
1791 	/*
1792 	 * Digests are always disabled during login phase.
1793 	 */
1794 	is->is_conn->ic_header_crc32c = false;
1795 	is->is_conn->ic_data_crc32c = false;
1796 
1797 	return (error);
1798 }
1799 
1800 static int
1801 iscsi_ioctl_daemon_send(struct iscsi_softc *sc,
1802     struct iscsi_daemon_send *ids)
1803 {
1804 	struct iscsi_session *is;
1805 	struct icl_pdu *ip;
1806 	size_t datalen;
1807 	void *data;
1808 	int error;
1809 
1810 	sx_slock(&sc->sc_lock);
1811 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1812 		if (is->is_id == ids->ids_session_id)
1813 			break;
1814 	}
1815 	if (is == NULL) {
1816 		sx_sunlock(&sc->sc_lock);
1817 		return (ESRCH);
1818 	}
1819 	sx_sunlock(&sc->sc_lock);
1820 
1821 	if (is->is_login_phase == false)
1822 		return (EBUSY);
1823 
1824 	if (is->is_terminating || is->is_reconnecting)
1825 		return (EIO);
1826 
1827 	datalen = ids->ids_data_segment_len;
1828 	if (datalen > is->is_conn->ic_max_send_data_segment_length)
1829 		return (EINVAL);
1830 	if (datalen > 0) {
1831 		data = malloc(datalen, M_ISCSI, M_WAITOK);
1832 		error = copyin(ids->ids_data_segment, data, datalen);
1833 		if (error != 0) {
1834 			free(data, M_ISCSI);
1835 			return (error);
1836 		}
1837 	}
1838 
1839 	ip = icl_pdu_new(is->is_conn, M_WAITOK);
1840 	memcpy(ip->ip_bhs, ids->ids_bhs, sizeof(*ip->ip_bhs));
1841 	if (datalen > 0) {
1842 		error = icl_pdu_append_data(ip, data, datalen, M_WAITOK);
1843 		KASSERT(error == 0, ("icl_pdu_append_data(..., M_WAITOK) failed"));
1844 		free(data, M_ISCSI);
1845 	}
1846 	iscsi_pdu_queue(ip);
1847 
1848 	return (0);
1849 }
1850 
1851 static int
1852 iscsi_ioctl_daemon_receive(struct iscsi_softc *sc,
1853     struct iscsi_daemon_receive *idr)
1854 {
1855 	struct iscsi_session *is;
1856 	struct icl_pdu *ip;
1857 	void *data;
1858 	int error;
1859 
1860 	sx_slock(&sc->sc_lock);
1861 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1862 		if (is->is_id == idr->idr_session_id)
1863 			break;
1864 	}
1865 	if (is == NULL) {
1866 		sx_sunlock(&sc->sc_lock);
1867 		return (ESRCH);
1868 	}
1869 	sx_sunlock(&sc->sc_lock);
1870 
1871 	if (is->is_login_phase == false)
1872 		return (EBUSY);
1873 
1874 	ISCSI_SESSION_LOCK(is);
1875 	while (is->is_login_pdu == NULL &&
1876 	    is->is_terminating == false &&
1877 	    is->is_reconnecting == false) {
1878 		error = cv_wait_sig(&is->is_login_cv, &is->is_lock);
1879 		if (error != 0) {
1880 			ISCSI_SESSION_UNLOCK(is);
1881 			return (error);
1882 		}
1883 	}
1884 	if (is->is_terminating || is->is_reconnecting) {
1885 		ISCSI_SESSION_UNLOCK(is);
1886 		return (EIO);
1887 	}
1888 	ip = is->is_login_pdu;
1889 	is->is_login_pdu = NULL;
1890 	ISCSI_SESSION_UNLOCK(is);
1891 
1892 	if (ip->ip_data_len > idr->idr_data_segment_len) {
1893 		icl_pdu_free(ip);
1894 		return (EMSGSIZE);
1895 	}
1896 
1897 	copyout(ip->ip_bhs, idr->idr_bhs, sizeof(*ip->ip_bhs));
1898 	if (ip->ip_data_len > 0) {
1899 		data = malloc(ip->ip_data_len, M_ISCSI, M_WAITOK);
1900 		icl_pdu_get_data(ip, 0, data, ip->ip_data_len);
1901 		copyout(data, idr->idr_data_segment, ip->ip_data_len);
1902 		free(data, M_ISCSI);
1903 	}
1904 
1905 	icl_pdu_free(ip);
1906 
1907 	return (0);
1908 }
1909 #endif /* ICL_KERNEL_PROXY */
1910 
1911 static void
1912 iscsi_sanitize_session_conf(struct iscsi_session_conf *isc)
1913 {
1914 	/*
1915 	 * Just make sure all the fields are null-terminated.
1916 	 *
1917 	 * XXX: This is not particularly secure.  We should
1918 	 * 	create our own conf and then copy in relevant
1919 	 * 	fields.
1920 	 */
1921 	isc->isc_initiator[ISCSI_NAME_LEN - 1] = '\0';
1922 	isc->isc_initiator_addr[ISCSI_ADDR_LEN - 1] = '\0';
1923 	isc->isc_initiator_alias[ISCSI_ALIAS_LEN - 1] = '\0';
1924 	isc->isc_target[ISCSI_NAME_LEN - 1] = '\0';
1925 	isc->isc_target_addr[ISCSI_ADDR_LEN - 1] = '\0';
1926 	isc->isc_user[ISCSI_NAME_LEN - 1] = '\0';
1927 	isc->isc_secret[ISCSI_SECRET_LEN - 1] = '\0';
1928 	isc->isc_mutual_user[ISCSI_NAME_LEN - 1] = '\0';
1929 	isc->isc_mutual_secret[ISCSI_SECRET_LEN - 1] = '\0';
1930 }
1931 
1932 static bool
1933 iscsi_valid_session_conf(const struct iscsi_session_conf *isc)
1934 {
1935 
1936 	if (isc->isc_initiator[0] == '\0') {
1937 		ISCSI_DEBUG("empty isc_initiator");
1938 		return (false);
1939 	}
1940 
1941 	if (isc->isc_target_addr[0] == '\0') {
1942 		ISCSI_DEBUG("empty isc_target_addr");
1943 		return (false);
1944 	}
1945 
1946 	if (isc->isc_discovery != 0 && isc->isc_target[0] != 0) {
1947 		ISCSI_DEBUG("non-empty isc_target for discovery session");
1948 		return (false);
1949 	}
1950 
1951 	if (isc->isc_discovery == 0 && isc->isc_target[0] == 0) {
1952 		ISCSI_DEBUG("empty isc_target for non-discovery session");
1953 		return (false);
1954 	}
1955 
1956 	return (true);
1957 }
1958 
1959 static int
1960 iscsi_ioctl_session_add(struct iscsi_softc *sc, struct iscsi_session_add *isa)
1961 {
1962 	struct iscsi_session *is;
1963 	const struct iscsi_session *is2;
1964 	int error;
1965 	sbintime_t sbt, pr;
1966 
1967 	iscsi_sanitize_session_conf(&isa->isa_conf);
1968 	if (iscsi_valid_session_conf(&isa->isa_conf) == false)
1969 		return (EINVAL);
1970 
1971 	is = malloc(sizeof(*is), M_ISCSI, M_ZERO | M_WAITOK);
1972 	memcpy(&is->is_conf, &isa->isa_conf, sizeof(is->is_conf));
1973 
1974 	sx_xlock(&sc->sc_lock);
1975 
1976 	/*
1977 	 * Prevent duplicates.
1978 	 */
1979 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
1980 		if (!!is->is_conf.isc_discovery !=
1981 		    !!is2->is_conf.isc_discovery)
1982 			continue;
1983 
1984 		if (strcmp(is->is_conf.isc_target_addr,
1985 		    is2->is_conf.isc_target_addr) != 0)
1986 			continue;
1987 
1988 		if (is->is_conf.isc_discovery == 0 &&
1989 		    strcmp(is->is_conf.isc_target,
1990 		    is2->is_conf.isc_target) != 0)
1991 			continue;
1992 
1993 		sx_xunlock(&sc->sc_lock);
1994 		free(is, M_ISCSI);
1995 		return (EBUSY);
1996 	}
1997 
1998 	is->is_conn = icl_new_conn(is->is_conf.isc_offload,
1999 	    is->is_conf.isc_iser, "iscsi", &is->is_lock);
2000 	if (is->is_conn == NULL) {
2001 		sx_xunlock(&sc->sc_lock);
2002 		free(is, M_ISCSI);
2003 		return (EINVAL);
2004 	}
2005 	is->is_conn->ic_receive = iscsi_receive_callback;
2006 	is->is_conn->ic_error = iscsi_error_callback;
2007 	is->is_conn->ic_prv0 = is;
2008 	TAILQ_INIT(&is->is_outstanding);
2009 	STAILQ_INIT(&is->is_postponed);
2010 	mtx_init(&is->is_lock, "iscsi_lock", NULL, MTX_DEF);
2011 	cv_init(&is->is_maintenance_cv, "iscsi_mt");
2012 #ifdef ICL_KERNEL_PROXY
2013 	cv_init(&is->is_login_cv, "iscsi_login");
2014 #endif
2015 
2016 	/*
2017 	 * Set some default values, from RFC 3720, section 12.
2018 	 *
2019 	 * These values are updated by the handoff IOCTL, but are
2020 	 * needed prior to the handoff to support sending the ISER
2021 	 * login PDU.
2022 	 */
2023 	is->is_conn->ic_max_recv_data_segment_length = 8192;
2024 	is->is_conn->ic_max_send_data_segment_length = 8192;
2025 	is->is_max_burst_length = 262144;
2026 	is->is_first_burst_length = 65536;
2027 
2028 	is->is_softc = sc;
2029 	sc->sc_last_session_id++;
2030 	is->is_id = sc->sc_last_session_id;
2031 	is->is_isid[0] = 0x80; /* RFC 3720, 10.12.5: 10b, "Random" ISID. */
2032 	arc4rand(&is->is_isid[1], 5, 0);
2033 	is->is_tsih = 0;
2034 	callout_init(&is->is_callout, 1);
2035 
2036 	error = kthread_add(iscsi_maintenance_thread, is, NULL, NULL, 0, 0, "iscsimt");
2037 	if (error != 0) {
2038 		ISCSI_SESSION_WARN(is, "kthread_add(9) failed with error %d", error);
2039 		sx_xunlock(&sc->sc_lock);
2040 		return (error);
2041 	}
2042 	is->is_ping_timeout = is->is_conf.isc_ping_timeout;
2043 	if (is->is_ping_timeout < 0)
2044 		is->is_ping_timeout = ping_timeout;
2045 	is->is_login_timeout = is->is_conf.isc_login_timeout;
2046 	if (is->is_login_timeout < 0)
2047 		is->is_login_timeout = login_timeout;
2048 
2049 	sbt = mstosbt(995);
2050 	pr = mstosbt(10);
2051 	callout_reset_sbt(&is->is_callout, sbt, pr, iscsi_callout, is, 0);
2052 	TAILQ_INSERT_TAIL(&sc->sc_sessions, is, is_next);
2053 
2054 	ISCSI_SESSION_LOCK(is);
2055 	/*
2056 	 * Don't notify iscsid(8) if the session is disabled and it's not
2057 	 * a discovery session,
2058 	 */
2059 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
2060 		ISCSI_SESSION_UNLOCK(is);
2061 		sx_xunlock(&sc->sc_lock);
2062 		return (0);
2063 	}
2064 
2065 	is->is_waiting_for_iscsid = true;
2066 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
2067 	ISCSI_SESSION_UNLOCK(is);
2068 	cv_signal(&sc->sc_cv);
2069 	sx_xunlock(&sc->sc_lock);
2070 	return (0);
2071 }
2072 
2073 static bool
2074 iscsi_session_conf_matches(unsigned int id1, const struct iscsi_session_conf *c1,
2075     unsigned int id2, const struct iscsi_session_conf *c2)
2076 {
2077 
2078 	if (id2 != 0 && id2 != id1)
2079 		return (false);
2080 	if (c2->isc_target[0] != '\0' &&
2081 	    strcmp(c1->isc_target, c2->isc_target) != 0)
2082 		return (false);
2083 	if (c2->isc_target_addr[0] != '\0' &&
2084 	    strcmp(c1->isc_target_addr, c2->isc_target_addr) != 0)
2085 		return (false);
2086 	return (true);
2087 }
2088 
2089 static int
2090 iscsi_ioctl_session_remove(struct iscsi_softc *sc,
2091     struct iscsi_session_remove *isr)
2092 {
2093 	struct iscsi_session *is, *tmp;
2094 	bool found = false;
2095 
2096 	iscsi_sanitize_session_conf(&isr->isr_conf);
2097 
2098 	sx_xlock(&sc->sc_lock);
2099 	TAILQ_FOREACH_SAFE(is, &sc->sc_sessions, is_next, tmp) {
2100 		ISCSI_SESSION_LOCK(is);
2101 		if (iscsi_session_conf_matches(is->is_id, &is->is_conf,
2102 		    isr->isr_session_id, &isr->isr_conf)) {
2103 			found = true;
2104 			iscsi_session_logout(is);
2105 			iscsi_session_terminate(is);
2106 		}
2107 		ISCSI_SESSION_UNLOCK(is);
2108 	}
2109 	sx_xunlock(&sc->sc_lock);
2110 
2111 	if (!found)
2112 		return (ESRCH);
2113 
2114 	return (0);
2115 }
2116 
2117 static int
2118 iscsi_ioctl_session_list(struct iscsi_softc *sc, struct iscsi_session_list *isl)
2119 {
2120 	int error;
2121 	unsigned int i = 0;
2122 	struct iscsi_session *is;
2123 	struct iscsi_session_state iss;
2124 
2125 	sx_slock(&sc->sc_lock);
2126 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
2127 		if (i >= isl->isl_nentries) {
2128 			sx_sunlock(&sc->sc_lock);
2129 			return (EMSGSIZE);
2130 		}
2131 		memset(&iss, 0, sizeof(iss));
2132 		memcpy(&iss.iss_conf, &is->is_conf, sizeof(iss.iss_conf));
2133 		iss.iss_id = is->is_id;
2134 		strlcpy(iss.iss_target_alias, is->is_target_alias, sizeof(iss.iss_target_alias));
2135 		strlcpy(iss.iss_reason, is->is_reason, sizeof(iss.iss_reason));
2136 		strlcpy(iss.iss_offload, is->is_conn->ic_offload, sizeof(iss.iss_offload));
2137 
2138 		if (is->is_conn->ic_header_crc32c)
2139 			iss.iss_header_digest = ISCSI_DIGEST_CRC32C;
2140 		else
2141 			iss.iss_header_digest = ISCSI_DIGEST_NONE;
2142 
2143 		if (is->is_conn->ic_data_crc32c)
2144 			iss.iss_data_digest = ISCSI_DIGEST_CRC32C;
2145 		else
2146 			iss.iss_data_digest = ISCSI_DIGEST_NONE;
2147 
2148 		iss.iss_max_send_data_segment_length =
2149 		    is->is_conn->ic_max_send_data_segment_length;
2150 		iss.iss_max_recv_data_segment_length =
2151 		    is->is_conn->ic_max_recv_data_segment_length;
2152 		iss.iss_max_burst_length = is->is_max_burst_length;
2153 		iss.iss_first_burst_length = is->is_first_burst_length;
2154 		iss.iss_immediate_data = is->is_immediate_data;
2155 		iss.iss_connected = is->is_connected;
2156 
2157 		error = copyout(&iss, isl->isl_pstates + i, sizeof(iss));
2158 		if (error != 0) {
2159 			sx_sunlock(&sc->sc_lock);
2160 			return (error);
2161 		}
2162 		i++;
2163 	}
2164 	sx_sunlock(&sc->sc_lock);
2165 
2166 	isl->isl_nentries = i;
2167 
2168 	return (0);
2169 }
2170 
2171 static int
2172 iscsi_ioctl_session_modify(struct iscsi_softc *sc,
2173     struct iscsi_session_modify *ism)
2174 {
2175 	struct iscsi_session *is;
2176 	const struct iscsi_session *is2;
2177 
2178 	iscsi_sanitize_session_conf(&ism->ism_conf);
2179 	if (iscsi_valid_session_conf(&ism->ism_conf) == false)
2180 		return (EINVAL);
2181 
2182 	sx_xlock(&sc->sc_lock);
2183 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
2184 		ISCSI_SESSION_LOCK(is);
2185 		if (is->is_id == ism->ism_session_id) {
2186 			/* Note that the session remains locked. */
2187 			break;
2188 		}
2189 		ISCSI_SESSION_UNLOCK(is);
2190 	}
2191 	if (is == NULL) {
2192 		sx_xunlock(&sc->sc_lock);
2193 		return (ESRCH);
2194 	}
2195 
2196 	/*
2197 	 * Prevent duplicates.
2198 	 */
2199 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
2200 		if (is == is2)
2201 			continue;
2202 
2203 		if (!!ism->ism_conf.isc_discovery !=
2204 		    !!is2->is_conf.isc_discovery)
2205 			continue;
2206 
2207 		if (strcmp(ism->ism_conf.isc_target_addr,
2208 		    is2->is_conf.isc_target_addr) != 0)
2209 			continue;
2210 
2211 		if (ism->ism_conf.isc_discovery == 0 &&
2212 		    strcmp(ism->ism_conf.isc_target,
2213 		    is2->is_conf.isc_target) != 0)
2214 			continue;
2215 
2216 		ISCSI_SESSION_UNLOCK(is);
2217 		sx_xunlock(&sc->sc_lock);
2218 		return (EBUSY);
2219 	}
2220 
2221 	sx_xunlock(&sc->sc_lock);
2222 
2223 	memcpy(&is->is_conf, &ism->ism_conf, sizeof(is->is_conf));
2224 	ISCSI_SESSION_UNLOCK(is);
2225 
2226 	iscsi_session_reconnect(is);
2227 
2228 	return (0);
2229 }
2230 
2231 static int
2232 iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
2233     struct thread *td)
2234 {
2235 	struct iscsi_softc *sc;
2236 
2237 	sc = dev->si_drv1;
2238 
2239 	switch (cmd) {
2240 	case ISCSIDWAIT:
2241 		return (iscsi_ioctl_daemon_wait(sc,
2242 		    (struct iscsi_daemon_request *)arg, false));
2243 #ifdef COMPAT_FREEBSD13
2244 	case ISCSIDWAIT13:
2245 		return (iscsi_ioctl_daemon_wait(sc,
2246 		    (struct iscsi_daemon_request *)arg, true));
2247 #endif
2248 	case ISCSIDLIMITS:
2249 		return (iscsi_ioctl_daemon_limits(sc,
2250 		    (struct iscsi_daemon_limits *)arg));
2251 	case ISCSIDHANDOFF:
2252 		return (iscsi_ioctl_daemon_handoff(sc,
2253 		    (struct iscsi_daemon_handoff *)arg));
2254 	case ISCSIDFAIL:
2255 		return (iscsi_ioctl_daemon_fail(sc,
2256 		    (struct iscsi_daemon_fail *)arg));
2257 #ifdef ICL_KERNEL_PROXY
2258 	case ISCSIDCONNECT:
2259 		return (iscsi_ioctl_daemon_connect(sc,
2260 		    (struct iscsi_daemon_connect *)arg));
2261 	case ISCSIDSEND:
2262 		return (iscsi_ioctl_daemon_send(sc,
2263 		    (struct iscsi_daemon_send *)arg));
2264 	case ISCSIDRECEIVE:
2265 		return (iscsi_ioctl_daemon_receive(sc,
2266 		    (struct iscsi_daemon_receive *)arg));
2267 #endif /* ICL_KERNEL_PROXY */
2268 	case ISCSISADD:
2269 		return (iscsi_ioctl_session_add(sc,
2270 		    (struct iscsi_session_add *)arg));
2271 	case ISCSISREMOVE:
2272 		return (iscsi_ioctl_session_remove(sc,
2273 		    (struct iscsi_session_remove *)arg));
2274 	case ISCSISLIST:
2275 		return (iscsi_ioctl_session_list(sc,
2276 		    (struct iscsi_session_list *)arg));
2277 	case ISCSISMODIFY:
2278 		return (iscsi_ioctl_session_modify(sc,
2279 		    (struct iscsi_session_modify *)arg));
2280 	default:
2281 		return (EINVAL);
2282 	}
2283 }
2284 
2285 static struct iscsi_outstanding *
2286 iscsi_outstanding_find(struct iscsi_session *is, uint32_t initiator_task_tag)
2287 {
2288 	struct iscsi_outstanding *io;
2289 
2290 	ISCSI_SESSION_LOCK_ASSERT(is);
2291 
2292 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
2293 		if (io->io_initiator_task_tag == initiator_task_tag)
2294 			return (io);
2295 	}
2296 	return (NULL);
2297 }
2298 
2299 static struct iscsi_outstanding *
2300 iscsi_outstanding_find_ccb(struct iscsi_session *is, union ccb *ccb)
2301 {
2302 	struct iscsi_outstanding *io;
2303 
2304 	ISCSI_SESSION_LOCK_ASSERT(is);
2305 
2306 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
2307 		if (io->io_ccb == ccb)
2308 			return (io);
2309 	}
2310 	return (NULL);
2311 }
2312 
2313 static struct iscsi_outstanding *
2314 iscsi_outstanding_add(struct iscsi_session *is, struct icl_pdu *request,
2315     union ccb *ccb, uint32_t *initiator_task_tagp)
2316 {
2317 	struct iscsi_outstanding *io;
2318 	int error;
2319 
2320 	ISCSI_SESSION_LOCK_ASSERT(is);
2321 
2322 	io = uma_zalloc(iscsi_outstanding_zone, M_NOWAIT | M_ZERO);
2323 	if (io == NULL) {
2324 		ISCSI_SESSION_WARN(is, "failed to allocate %zd bytes",
2325 		    sizeof(*io));
2326 		return (NULL);
2327 	}
2328 
2329 	error = icl_conn_task_setup(is->is_conn, request, &ccb->csio,
2330 	    initiator_task_tagp, &io->io_icl_prv);
2331 	if (error != 0) {
2332 		ISCSI_SESSION_WARN(is,
2333 		    "icl_conn_task_setup() failed with error %d", error);
2334 		uma_zfree(iscsi_outstanding_zone, io);
2335 		return (NULL);
2336 	}
2337 
2338 	KASSERT(iscsi_outstanding_find(is, *initiator_task_tagp) == NULL,
2339 	    ("initiator_task_tag 0x%x already added", *initiator_task_tagp));
2340 
2341 	io->io_initiator_task_tag = *initiator_task_tagp;
2342 	io->io_ccb = ccb;
2343 	TAILQ_INSERT_TAIL(&is->is_outstanding, io, io_next);
2344 	return (io);
2345 }
2346 
2347 static void
2348 iscsi_outstanding_remove(struct iscsi_session *is, struct iscsi_outstanding *io)
2349 {
2350 
2351 	ISCSI_SESSION_LOCK_ASSERT(is);
2352 
2353 	icl_conn_task_done(is->is_conn, io->io_icl_prv);
2354 	TAILQ_REMOVE(&is->is_outstanding, io, io_next);
2355 	uma_zfree(iscsi_outstanding_zone, io);
2356 }
2357 
2358 static void
2359 iscsi_action_abort(struct iscsi_session *is, union ccb *ccb)
2360 {
2361 	struct icl_pdu *request;
2362 	struct iscsi_bhs_task_management_request *bhstmr;
2363 	struct ccb_abort *cab = &ccb->cab;
2364 	struct iscsi_outstanding *io, *aio;
2365 	uint32_t initiator_task_tag;
2366 
2367 	ISCSI_SESSION_LOCK_ASSERT(is);
2368 
2369 #if 0
2370 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2371 #else
2372 	if (is->is_login_phase) {
2373 		ccb->ccb_h.status = CAM_REQ_ABORTED;
2374 		xpt_done(ccb);
2375 		return;
2376 	}
2377 #endif
2378 
2379 	aio = iscsi_outstanding_find_ccb(is, cab->abort_ccb);
2380 	if (aio == NULL) {
2381 		ccb->ccb_h.status = CAM_REQ_CMP;
2382 		xpt_done(ccb);
2383 		return;
2384 	}
2385 
2386 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2387 	if (request == NULL) {
2388 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2389 		xpt_done(ccb);
2390 		return;
2391 	}
2392 
2393 	initiator_task_tag = is->is_initiator_task_tag++;
2394 	if (initiator_task_tag == 0xffffffff)
2395 		initiator_task_tag = is->is_initiator_task_tag++;
2396 
2397 	io = iscsi_outstanding_add(is, request, NULL, &initiator_task_tag);
2398 	if (io == NULL) {
2399 		icl_pdu_free(request);
2400 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2401 		xpt_done(ccb);
2402 		return;
2403 	}
2404 	io->io_referenced_task_tag = aio->io_initiator_task_tag;
2405 
2406 	bhstmr = (struct iscsi_bhs_task_management_request *)request->ip_bhs;
2407 	bhstmr->bhstmr_opcode = ISCSI_BHS_OPCODE_TASK_REQUEST;
2408 	bhstmr->bhstmr_function = 0x80 | BHSTMR_FUNCTION_ABORT_TASK;
2409 	bhstmr->bhstmr_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2410 	bhstmr->bhstmr_initiator_task_tag = initiator_task_tag;
2411 	bhstmr->bhstmr_referenced_task_tag = aio->io_initiator_task_tag;
2412 
2413 	iscsi_pdu_queue_locked(request);
2414 }
2415 
2416 static void
2417 iscsi_action_scsiio(struct iscsi_session *is, union ccb *ccb)
2418 {
2419 	struct icl_pdu *request;
2420 	struct iscsi_bhs_scsi_command *bhssc;
2421 	struct ccb_scsiio *csio;
2422 	struct iscsi_outstanding *io;
2423 	size_t len;
2424 	uint32_t initiator_task_tag;
2425 	int error;
2426 
2427 	ISCSI_SESSION_LOCK_ASSERT(is);
2428 
2429 #if 0
2430 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2431 #else
2432 	if (is->is_login_phase) {
2433 		ISCSI_SESSION_DEBUG(is, "called during login phase");
2434 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2435 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2436 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2437 		}
2438 		ccb->ccb_h.status = CAM_REQ_ABORTED | CAM_DEV_QFRZN;
2439 		xpt_done(ccb);
2440 		return;
2441 	}
2442 #endif
2443 
2444 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2445 	if (request == NULL) {
2446 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2447 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2448 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2449 		}
2450 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2451 		xpt_done(ccb);
2452 		return;
2453 	}
2454 
2455 	initiator_task_tag = is->is_initiator_task_tag++;
2456 	if (initiator_task_tag == 0xffffffff)
2457 		initiator_task_tag = is->is_initiator_task_tag++;
2458 
2459 	io = iscsi_outstanding_add(is, request, ccb, &initiator_task_tag);
2460 	if (io == NULL) {
2461 		icl_pdu_free(request);
2462 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2463 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2464 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2465 		}
2466 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2467 		xpt_done(ccb);
2468 		return;
2469 	}
2470 
2471 	csio = &ccb->csio;
2472 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
2473 	bhssc->bhssc_opcode = ISCSI_BHS_OPCODE_SCSI_COMMAND;
2474 	bhssc->bhssc_flags |= BHSSC_FLAGS_F;
2475 	switch (csio->ccb_h.flags & CAM_DIR_MASK) {
2476 	case CAM_DIR_IN:
2477 		bhssc->bhssc_flags |= BHSSC_FLAGS_R;
2478 		break;
2479 	case CAM_DIR_OUT:
2480 		bhssc->bhssc_flags |= BHSSC_FLAGS_W;
2481 		break;
2482 	}
2483 
2484 	if ((ccb->ccb_h.flags & CAM_TAG_ACTION_VALID) != 0) {
2485 		switch (csio->tag_action) {
2486 		case MSG_HEAD_OF_Q_TAG:
2487 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_HOQ;
2488 			break;
2489 		case MSG_ORDERED_Q_TAG:
2490 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ORDERED;
2491 			break;
2492 		case MSG_ACA_TASK:
2493 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ACA;
2494 			break;
2495 		case MSG_SIMPLE_Q_TAG:
2496 		default:
2497 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_SIMPLE;
2498 			break;
2499 		}
2500 	} else
2501 		bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_UNTAGGED;
2502 
2503 	if (is->is_protocol_level >= 2) {
2504 		bhssc->bhssc_pri = (csio->priority << BHSSC_PRI_SHIFT) &
2505 		    BHSSC_PRI_MASK;
2506 	}
2507 
2508 	bhssc->bhssc_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2509 	bhssc->bhssc_initiator_task_tag = initiator_task_tag;
2510 	bhssc->bhssc_expected_data_transfer_length = htonl(csio->dxfer_len);
2511 	KASSERT(csio->cdb_len <= sizeof(bhssc->bhssc_cdb),
2512 	    ("unsupported CDB size %zd", (size_t)csio->cdb_len));
2513 
2514 	if (csio->ccb_h.flags & CAM_CDB_POINTER)
2515 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_ptr, csio->cdb_len);
2516 	else
2517 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_bytes, csio->cdb_len);
2518 
2519 	if (is->is_immediate_data &&
2520 	    (csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT) {
2521 		len = csio->dxfer_len;
2522 		//ISCSI_SESSION_DEBUG(is, "adding %zd of immediate data", len);
2523 		if (len > is->is_first_burst_length) {
2524 			ISCSI_SESSION_DEBUG(is, "len %zd -> %d", len, is->is_first_burst_length);
2525 			len = is->is_first_burst_length;
2526 		}
2527 		if (len > is->is_conn->ic_max_send_data_segment_length) {
2528 			ISCSI_SESSION_DEBUG(is, "len %zd -> %d", len,
2529 			    is->is_conn->ic_max_send_data_segment_length);
2530 			len = is->is_conn->ic_max_send_data_segment_length;
2531 		}
2532 
2533 		error = iscsi_pdu_append_data_csio(request, csio, 0, len,
2534 		    M_NOWAIT | ICL_NOCOPY);
2535 		if (error != 0) {
2536 			iscsi_outstanding_remove(is, io);
2537 			icl_pdu_free(request);
2538 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2539 				xpt_freeze_devq(ccb->ccb_h.path, 1);
2540 				ISCSI_SESSION_DEBUG(is, "freezing devq");
2541 			}
2542 			ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2543 			xpt_done(ccb);
2544 			return;
2545 		}
2546 	}
2547 	iscsi_pdu_queue_locked(request);
2548 }
2549 
2550 static void
2551 iscsi_action(struct cam_sim *sim, union ccb *ccb)
2552 {
2553 	struct iscsi_session *is;
2554 
2555 	is = cam_sim_softc(sim);
2556 
2557 	ISCSI_SESSION_LOCK_ASSERT(is);
2558 
2559 	if (is->is_terminating ||
2560 	    (is->is_connected == false && fail_on_disconnection)) {
2561 		ccb->ccb_h.status = CAM_DEV_NOT_THERE;
2562 		xpt_done(ccb);
2563 		return;
2564 	}
2565 
2566 	/*
2567 	 * Make sure CAM doesn't sneak in a CCB just after freezing the queue.
2568 	 */
2569 	if (is->is_simq_frozen == true) {
2570 		ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
2571 		ccb->ccb_h.status |= CAM_REQUEUE_REQ;
2572 		/* Don't freeze the devq - the SIM queue is already frozen. */
2573 		xpt_done(ccb);
2574 		return;
2575 	}
2576 
2577 	switch (ccb->ccb_h.func_code) {
2578 	case XPT_PATH_INQ:
2579 	{
2580 		struct ccb_pathinq *cpi = &ccb->cpi;
2581 
2582 		cpi->version_num = 1;
2583 		cpi->hba_inquiry = PI_TAG_ABLE;
2584 		cpi->target_sprt = 0;
2585 		cpi->hba_misc = PIM_EXTLUNS;
2586 		/*
2587 		 * XXX: It shouldn't ever be NULL; this could be turned
2588 		 *      into a KASSERT eventually.
2589 		 */
2590 		if (is->is_conn == NULL)
2591 			ISCSI_WARN("NULL conn");
2592 		else if (is->is_conn->ic_unmapped)
2593 			cpi->hba_misc |= PIM_UNMAPPED;
2594 		cpi->hba_eng_cnt = 0;
2595 		cpi->max_target = 0;
2596 		/*
2597 		 * Note that the variable below is only relevant for targets
2598 		 * that don't claim compliance with anything above SPC2, which
2599 		 * means they don't support REPORT_LUNS.
2600 		 */
2601 		cpi->max_lun = 255;
2602 		cpi->initiator_id = ~0;
2603 		strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
2604 		strlcpy(cpi->hba_vid, "iSCSI", HBA_IDLEN);
2605 		strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
2606 		cpi->unit_number = cam_sim_unit(sim);
2607 		cpi->bus_id = cam_sim_bus(sim);
2608 		cpi->base_transfer_speed = 150000; /* XXX */
2609 		cpi->transport = XPORT_ISCSI;
2610 		cpi->transport_version = 0;
2611 		cpi->protocol = PROTO_SCSI;
2612 		cpi->protocol_version = SCSI_REV_SPC3;
2613 		cpi->maxio = maxphys;
2614 		cpi->ccb_h.status = CAM_REQ_CMP;
2615 		break;
2616 	}
2617 	case XPT_GET_TRAN_SETTINGS:
2618 	{
2619 		struct ccb_trans_settings	*cts;
2620 		struct ccb_trans_settings_scsi	*scsi;
2621 
2622 		cts = &ccb->cts;
2623 		scsi = &cts->proto_specific.scsi;
2624 
2625 		cts->protocol = PROTO_SCSI;
2626 		cts->protocol_version = SCSI_REV_SPC3;
2627 		cts->transport = XPORT_ISCSI;
2628 		cts->transport_version = 0;
2629 		scsi->valid = CTS_SCSI_VALID_TQ;
2630 		scsi->flags = CTS_SCSI_FLAGS_TAG_ENB;
2631 		cts->ccb_h.status = CAM_REQ_CMP;
2632 		break;
2633 	}
2634 	case XPT_CALC_GEOMETRY:
2635 		cam_calc_geometry(&ccb->ccg, /*extended*/1);
2636 		ccb->ccb_h.status = CAM_REQ_CMP;
2637 		break;
2638 #if 0
2639 	/*
2640 	 * XXX: What's the point?
2641 	 */
2642 	case XPT_RESET_BUS:
2643 	case XPT_TERM_IO:
2644 		ISCSI_SESSION_DEBUG(is, "faking success for reset, abort, or term_io");
2645 		ccb->ccb_h.status = CAM_REQ_CMP;
2646 		break;
2647 #endif
2648 	case XPT_ABORT:
2649 		iscsi_action_abort(is, ccb);
2650 		return;
2651 	case XPT_SCSI_IO:
2652 		iscsi_action_scsiio(is, ccb);
2653 		return;
2654 	default:
2655 #if 0
2656 		ISCSI_SESSION_DEBUG(is, "got unsupported code 0x%x", ccb->ccb_h.func_code);
2657 #endif
2658 		ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
2659 		break;
2660 	}
2661 	xpt_done(ccb);
2662 }
2663 
2664 static void
2665 iscsi_terminate_sessions(struct iscsi_softc *sc)
2666 {
2667 	struct iscsi_session *is;
2668 
2669 	sx_slock(&sc->sc_lock);
2670 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next)
2671 		iscsi_session_terminate(is);
2672 	while(!TAILQ_EMPTY(&sc->sc_sessions)) {
2673 		ISCSI_DEBUG("waiting for sessions to terminate");
2674 		cv_wait(&sc->sc_cv, &sc->sc_lock);
2675 	}
2676 	ISCSI_DEBUG("all sessions terminated");
2677 	sx_sunlock(&sc->sc_lock);
2678 }
2679 
2680 static void
2681 iscsi_shutdown_pre(struct iscsi_softc *sc)
2682 {
2683 	struct iscsi_session *is;
2684 
2685 	if (!fail_on_shutdown)
2686 		return;
2687 
2688 	/*
2689 	 * If we have any sessions waiting for reconnection, request
2690 	 * maintenance thread to fail them immediately instead of waiting
2691 	 * for reconnect timeout.
2692 	 *
2693 	 * This prevents LUNs with mounted filesystems that are supported
2694 	 * by disconnected iSCSI sessions from hanging, however it will
2695 	 * fail all queued BIOs.
2696 	 */
2697 	ISCSI_DEBUG("forcing failing all disconnected sessions due to shutdown");
2698 
2699 	fail_on_disconnection = 1;
2700 
2701 	sx_slock(&sc->sc_lock);
2702 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
2703 		ISCSI_SESSION_LOCK(is);
2704 		if (!is->is_connected) {
2705 			ISCSI_SESSION_DEBUG(is, "force failing disconnected session early");
2706 			iscsi_session_reconnect(is);
2707 		}
2708 		ISCSI_SESSION_UNLOCK(is);
2709 	}
2710 	sx_sunlock(&sc->sc_lock);
2711 }
2712 
2713 static void
2714 iscsi_shutdown_post(struct iscsi_softc *sc)
2715 {
2716 
2717 	if (!KERNEL_PANICKED()) {
2718 		ISCSI_DEBUG("removing all sessions due to shutdown");
2719 		iscsi_terminate_sessions(sc);
2720 	}
2721 }
2722 
2723 static int
2724 iscsi_load(void)
2725 {
2726 	int error;
2727 
2728 	sc = malloc(sizeof(*sc), M_ISCSI, M_ZERO | M_WAITOK);
2729 	sx_init(&sc->sc_lock, "iscsi");
2730 	TAILQ_INIT(&sc->sc_sessions);
2731 	cv_init(&sc->sc_cv, "iscsi_cv");
2732 
2733 	iscsi_outstanding_zone = uma_zcreate("iscsi_outstanding",
2734 	    sizeof(struct iscsi_outstanding), NULL, NULL, NULL, NULL,
2735 	    UMA_ALIGN_PTR, 0);
2736 
2737 	error = make_dev_p(MAKEDEV_CHECKNAME, &sc->sc_cdev, &iscsi_cdevsw,
2738 	    NULL, UID_ROOT, GID_WHEEL, 0600, "iscsi");
2739 	if (error != 0) {
2740 		ISCSI_WARN("failed to create device node, error %d", error);
2741 		return (error);
2742 	}
2743 	sc->sc_cdev->si_drv1 = sc;
2744 
2745 	sc->sc_shutdown_pre_eh = EVENTHANDLER_REGISTER(shutdown_pre_sync,
2746 	    iscsi_shutdown_pre, sc, SHUTDOWN_PRI_FIRST);
2747 	/*
2748 	 * shutdown_post_sync needs to run after filesystem shutdown and before
2749 	 * CAM shutdown - otherwise when rebooting with an iSCSI session that is
2750 	 * disconnected but has outstanding requests, dashutdown() will hang on
2751 	 * cam_periph_runccb().
2752 	 */
2753 	sc->sc_shutdown_post_eh = EVENTHANDLER_REGISTER(shutdown_post_sync,
2754 	    iscsi_shutdown_post, sc, SHUTDOWN_PRI_DEFAULT - 1);
2755 
2756 	return (0);
2757 }
2758 
2759 static int
2760 iscsi_unload(void)
2761 {
2762 
2763 	/* Awaken any threads asleep in iscsi_ioctl(). */
2764 	sx_xlock(&sc->sc_lock);
2765 	sc->sc_unloading = true;
2766 	cv_signal(&sc->sc_cv);
2767 	sx_xunlock(&sc->sc_lock);
2768 
2769 	if (sc->sc_cdev != NULL) {
2770 		ISCSI_DEBUG("removing device node");
2771 		destroy_dev(sc->sc_cdev);
2772 		ISCSI_DEBUG("device node removed");
2773 	}
2774 
2775 	if (sc->sc_shutdown_pre_eh != NULL)
2776 		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, sc->sc_shutdown_pre_eh);
2777 	if (sc->sc_shutdown_post_eh != NULL)
2778 		EVENTHANDLER_DEREGISTER(shutdown_post_sync, sc->sc_shutdown_post_eh);
2779 
2780 	iscsi_terminate_sessions(sc);
2781 
2782 	uma_zdestroy(iscsi_outstanding_zone);
2783 	sx_destroy(&sc->sc_lock);
2784 	cv_destroy(&sc->sc_cv);
2785 	free(sc, M_ISCSI);
2786 	return (0);
2787 }
2788 
2789 static int
2790 iscsi_quiesce(void)
2791 {
2792 	sx_slock(&sc->sc_lock);
2793 	if (!TAILQ_EMPTY(&sc->sc_sessions)) {
2794 		sx_sunlock(&sc->sc_lock);
2795 		return (EBUSY);
2796 	}
2797 	sx_sunlock(&sc->sc_lock);
2798 	return (0);
2799 }
2800 
2801 static int
2802 iscsi_modevent(module_t mod, int what, void *arg)
2803 {
2804 	int error;
2805 
2806 	switch (what) {
2807 	case MOD_LOAD:
2808 		error = iscsi_load();
2809 		break;
2810 	case MOD_UNLOAD:
2811 		error = iscsi_unload();
2812 		break;
2813 	case MOD_QUIESCE:
2814 		error = iscsi_quiesce();
2815 		break;
2816 	default:
2817 		error = EINVAL;
2818 		break;
2819 	}
2820 	return (error);
2821 }
2822 
2823 moduledata_t iscsi_data = {
2824 	"iscsi",
2825 	iscsi_modevent,
2826 	0
2827 };
2828 
2829 DECLARE_MODULE(iscsi, iscsi_data, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
2830 MODULE_DEPEND(iscsi, cam, 1, 1, 1);
2831 MODULE_DEPEND(iscsi, icl, 1, 1, 1);
2832