diff --git a/sys/dev/iscsi/iscsi.c b/sys/dev/iscsi/iscsi.c
index 093ba51d265e..cc860e3f68a8 100644
--- a/sys/dev/iscsi/iscsi.c
+++ b/sys/dev/iscsi/iscsi.c
@@ -1,2662 +1,2686 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2012 The FreeBSD Foundation
  *
  * This software was developed by Edward Tomasz Napierala under sponsorship
  * from the FreeBSD Foundation.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/condvar.h>
 #include <sys/conf.h>
 #include <sys/endian.h>
 #include <sys/eventhandler.h>
 #include <sys/file.h>
 #include <sys/kernel.h>
 #include <sys/kthread.h>
 #include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mutex.h>
 #include <sys/module.h>
 #include <sys/socket.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 #include <sys/sx.h>
 #include <vm/uma.h>
 
 #include <cam/cam.h>
 #include <cam/cam_ccb.h>
 #include <cam/cam_xpt.h>
 #include <cam/cam_debug.h>
 #include <cam/cam_sim.h>
 #include <cam/cam_xpt_sim.h>
 #include <cam/cam_xpt_periph.h>
 #include <cam/cam_periph.h>
 #include <cam/scsi/scsi_all.h>
 #include <cam/scsi/scsi_message.h>
 
 #include <dev/iscsi/icl.h>
 #include <dev/iscsi/icl_wrappers.h>
 #include <dev/iscsi/iscsi_ioctl.h>
 #include <dev/iscsi/iscsi_proto.h>
 #include <dev/iscsi/iscsi.h>
 
 #ifdef ICL_KERNEL_PROXY
 #include <sys/socketvar.h>
 #endif
 
 #ifdef ICL_KERNEL_PROXY
 FEATURE(iscsi_kernel_proxy, "iSCSI initiator built with ICL_KERNEL_PROXY");
 #endif
 
 /*
  * XXX: This is global so the iscsi_unload() can access it.
  * 	Think about how to do this properly.
  */
 static struct iscsi_softc	*sc;
 
 SYSCTL_NODE(_kern, OID_AUTO, iscsi, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
     "iSCSI initiator");
 static int debug = 1;
 SYSCTL_INT(_kern_iscsi, OID_AUTO, debug, CTLFLAG_RWTUN,
     &debug, 0, "Enable debug messages");
 static int ping_timeout = 5;
 SYSCTL_INT(_kern_iscsi, OID_AUTO, ping_timeout, CTLFLAG_RWTUN, &ping_timeout,
     0, "Timeout for ping (NOP-Out) requests, in seconds");
 static int iscsid_timeout = 60;
 SYSCTL_INT(_kern_iscsi, OID_AUTO, iscsid_timeout, CTLFLAG_RWTUN, &iscsid_timeout,
     0, "Time to wait for iscsid(8) to handle reconnection, in seconds");
 static int login_timeout = 60;
 SYSCTL_INT(_kern_iscsi, OID_AUTO, login_timeout, CTLFLAG_RWTUN, &login_timeout,
     0, "Time to wait for iscsid(8) to finish Login Phase, in seconds");
 static int maxtags = 255;
 SYSCTL_INT(_kern_iscsi, OID_AUTO, maxtags, CTLFLAG_RWTUN, &maxtags,
     0, "Max number of IO requests queued");
 static int fail_on_disconnection = 0;
 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_disconnection, CTLFLAG_RWTUN,
     &fail_on_disconnection, 0, "Destroy CAM SIM on connection failure");
 static int fail_on_shutdown = 1;
 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_shutdown, CTLFLAG_RWTUN,
     &fail_on_shutdown, 0, "Fail disconnected sessions on shutdown");
 
 static MALLOC_DEFINE(M_ISCSI, "iSCSI", "iSCSI initiator");
 static uma_zone_t iscsi_outstanding_zone;
 
 #define	CONN_SESSION(X)	((struct iscsi_session *)X->ic_prv0)
 #define	PDU_SESSION(X)	(CONN_SESSION(X->ip_conn))
 
 #define	ISCSI_DEBUG(X, ...)						\
 	do {								\
 		if (debug > 1) 						\
 			printf("%s: " X "\n", __func__, ## __VA_ARGS__);\
 	} while (0)
 
 #define	ISCSI_WARN(X, ...)						\
 	do {								\
 		if (debug > 0) {					\
 			printf("WARNING: %s: " X "\n",			\
 			    __func__, ## __VA_ARGS__);			\
 		}							\
 	} while (0)
 
 #define	ISCSI_SESSION_DEBUG(S, X, ...)					\
 	do {								\
 		if (debug > 1) {					\
 			printf("%s: %s (%s): " X "\n",			\
 			    __func__, S->is_conf.isc_target_addr,	\
 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
 		}							\
 	} while (0)
 
 #define	ISCSI_SESSION_WARN(S, X, ...)					\
 	do {								\
 		if (debug > 0) {					\
 			printf("WARNING: %s (%s): " X "\n",		\
 			    S->is_conf.isc_target_addr,			\
 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
 		}							\
 	} while (0)
 
 #define ISCSI_SESSION_LOCK(X)		mtx_lock(&X->is_lock)
 #define ISCSI_SESSION_UNLOCK(X)		mtx_unlock(&X->is_lock)
 #define ISCSI_SESSION_LOCK_ASSERT(X)	mtx_assert(&X->is_lock, MA_OWNED)
 #define ISCSI_SESSION_LOCK_ASSERT_NOT(X) mtx_assert(&X->is_lock, MA_NOTOWNED)
 
 static int	iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg,
 		    int mode, struct thread *td);
 
 static struct cdevsw iscsi_cdevsw = {
      .d_version = D_VERSION,
      .d_ioctl   = iscsi_ioctl,
      .d_name    = "iscsi",
 };
 
 static void	iscsi_pdu_queue_locked(struct icl_pdu *request);
 static void	iscsi_pdu_queue(struct icl_pdu *request);
 static void	iscsi_pdu_update_statsn(const struct icl_pdu *response);
 static void	iscsi_pdu_handle_nop_in(struct icl_pdu *response);
 static void	iscsi_pdu_handle_scsi_response(struct icl_pdu *response);
 static void	iscsi_pdu_handle_task_response(struct icl_pdu *response);
 static void	iscsi_pdu_handle_data_in(struct icl_pdu *response);
 static void	iscsi_pdu_handle_logout_response(struct icl_pdu *response);
 static void	iscsi_pdu_handle_r2t(struct icl_pdu *response);
 static void	iscsi_pdu_handle_async_message(struct icl_pdu *response);
 static void	iscsi_pdu_handle_reject(struct icl_pdu *response);
 static void	iscsi_session_reconnect(struct iscsi_session *is);
 static void	iscsi_session_terminate(struct iscsi_session *is);
 static void	iscsi_action(struct cam_sim *sim, union ccb *ccb);
 static struct iscsi_outstanding	*iscsi_outstanding_find(struct iscsi_session *is,
 		    uint32_t initiator_task_tag);
 static struct iscsi_outstanding	*iscsi_outstanding_add(struct iscsi_session *is,
 		    struct icl_pdu *request, union ccb *ccb,
 		    uint32_t *initiator_task_tagp);
 static void	iscsi_outstanding_remove(struct iscsi_session *is,
 		    struct iscsi_outstanding *io);
 
 static bool
 iscsi_pdu_prepare(struct icl_pdu *request)
 {
 	struct iscsi_session *is;
 	struct iscsi_bhs_scsi_command *bhssc;
 
 	is = PDU_SESSION(request);
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	/*
 	 * We're only using fields common for all the request
 	 * (initiator -> target) PDUs.
 	 */
 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
 
 	/*
 	 * Data-Out PDU does not contain CmdSN.
 	 */
 	if (bhssc->bhssc_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_OUT) {
 		if (ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn) &&
 		    (bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0) {
 			/*
 			 * Current MaxCmdSN prevents us from sending any more
 			 * SCSI Command PDUs to the target; postpone the PDU.
 			 * It will get resent by either iscsi_pdu_queue(),
 			 * or by maintenance thread.
 			 */
 #if 0
 			ISCSI_SESSION_DEBUG(is, "postponing send, CmdSN %u, "
 			    "ExpCmdSN %u, MaxCmdSN %u, opcode 0x%x",
 			    is->is_cmdsn, is->is_expcmdsn, is->is_maxcmdsn,
 			    bhssc->bhssc_opcode);
 #endif
 			return (true);
 		}
 		bhssc->bhssc_cmdsn = htonl(is->is_cmdsn);
 		if ((bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0)
 			is->is_cmdsn++;
 	}
 	bhssc->bhssc_expstatsn = htonl(is->is_statsn + 1);
 
 	return (false);
 }
 
 static void
 iscsi_session_send_postponed(struct iscsi_session *is)
 {
 	struct icl_pdu *request;
 	bool postpone;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	if (STAILQ_EMPTY(&is->is_postponed))
 		return;
 	while ((request = STAILQ_FIRST(&is->is_postponed)) != NULL) {
 		postpone = iscsi_pdu_prepare(request);
 		if (postpone)
 			return;
 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
 		icl_pdu_queue(request);
 	}
 	xpt_release_simq(is->is_sim, 1);
 }
 
 static void
 iscsi_pdu_queue_locked(struct icl_pdu *request)
 {
 	struct iscsi_session *is;
 	bool postpone;
 
 	is = PDU_SESSION(request);
 	ISCSI_SESSION_LOCK_ASSERT(is);
 	iscsi_session_send_postponed(is);
 	postpone = iscsi_pdu_prepare(request);
 	if (postpone) {
 		if (STAILQ_EMPTY(&is->is_postponed))
 			xpt_freeze_simq(is->is_sim, 1);
 		STAILQ_INSERT_TAIL(&is->is_postponed, request, ip_next);
 		return;
 	}
 	icl_pdu_queue(request);
 }
 
 static void
 iscsi_pdu_queue(struct icl_pdu *request)
 {
 	struct iscsi_session *is;
 
 	is = PDU_SESSION(request);
 	ISCSI_SESSION_LOCK(is);
 	iscsi_pdu_queue_locked(request);
 	ISCSI_SESSION_UNLOCK(is);
 }
 
 static void
 iscsi_session_logout(struct iscsi_session *is)
 {
 	struct icl_pdu *request;
 	struct iscsi_bhs_logout_request *bhslr;
 
 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
 	if (request == NULL)
 		return;
 
 	bhslr = (struct iscsi_bhs_logout_request *)request->ip_bhs;
 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST;
 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
 	iscsi_pdu_queue_locked(request);
 }
 
 static void
 iscsi_session_terminate_task(struct iscsi_session *is,
     struct iscsi_outstanding *io, cam_status status)
 {
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	if (io->io_ccb != NULL) {
 		io->io_ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
 		io->io_ccb->ccb_h.status |= status;
 		if ((io->io_ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 			io->io_ccb->ccb_h.status |= CAM_DEV_QFRZN;
 			xpt_freeze_devq(io->io_ccb->ccb_h.path, 1);
 			ISCSI_SESSION_DEBUG(is, "freezing devq");
 		}
 		xpt_done(io->io_ccb);
 	}
 	iscsi_outstanding_remove(is, io);
 }
 
 static void
 iscsi_session_terminate_tasks(struct iscsi_session *is, cam_status status)
 {
 	struct iscsi_outstanding *io, *tmp;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	TAILQ_FOREACH_SAFE(io, &is->is_outstanding, io_next, tmp) {
 		iscsi_session_terminate_task(is, io, status);
 	}
 }
 
 static void
 iscsi_session_cleanup(struct iscsi_session *is, bool destroy_sim)
 {
 	struct icl_pdu *pdu;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	/*
 	 * Don't queue any new PDUs.
 	 */
 	if (is->is_sim != NULL && is->is_simq_frozen == false) {
 		ISCSI_SESSION_DEBUG(is, "freezing");
 		xpt_freeze_simq(is->is_sim, 1);
 		is->is_simq_frozen = true;
 	}
 
 	/*
 	 * Remove postponed PDUs.
 	 */
 	if (!STAILQ_EMPTY(&is->is_postponed))
 		xpt_release_simq(is->is_sim, 1);
 	while ((pdu = STAILQ_FIRST(&is->is_postponed)) != NULL) {
 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
 		icl_pdu_free(pdu);
 	}
 
 	if (destroy_sim == false) {
 		/*
 		 * Terminate SCSI tasks, asking CAM to requeue them.
 		 */
 		iscsi_session_terminate_tasks(is, CAM_REQUEUE_REQ);
 		return;
 	}
 
 	iscsi_session_terminate_tasks(is, CAM_DEV_NOT_THERE);
 
 	if (is->is_sim == NULL)
 		return;
 
 	ISCSI_SESSION_DEBUG(is, "deregistering SIM");
 	xpt_async(AC_LOST_DEVICE, is->is_path, NULL);
 
 	if (is->is_simq_frozen) {
 		is->is_simq_frozen = false;
 		xpt_release_simq(is->is_sim, 1);
 	}
 
 	xpt_free_path(is->is_path);
 	is->is_path = NULL;
 	xpt_bus_deregister(cam_sim_path(is->is_sim));
 	cam_sim_free(is->is_sim, TRUE /*free_devq*/);
 	is->is_sim = NULL;
 	is->is_devq = NULL;
 }
 
 static void
 iscsi_maintenance_thread_reconnect(struct iscsi_session *is)
 {
 
 	icl_conn_close(is->is_conn);
 
 	ISCSI_SESSION_LOCK(is);
 
 	is->is_connected = false;
 	is->is_reconnecting = false;
 	is->is_login_phase = false;
 
 #ifdef ICL_KERNEL_PROXY
 	if (is->is_login_pdu != NULL) {
 		icl_pdu_free(is->is_login_pdu);
 		is->is_login_pdu = NULL;
 	}
 	cv_signal(&is->is_login_cv);
 #endif
 
 	if (fail_on_disconnection) {
 		ISCSI_SESSION_DEBUG(is, "connection failed, destroying devices");
 		iscsi_session_cleanup(is, true);
 	} else {
 		iscsi_session_cleanup(is, false);
 	}
 
 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
 	    ("destroying session with active tasks"));
 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
 	    ("destroying session with postponed PDUs"));
 
 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 
 	/*
 	 * Request immediate reconnection from iscsid(8).
 	 */
 	//ISCSI_SESSION_DEBUG(is, "waking up iscsid(8)");
 	is->is_waiting_for_iscsid = true;
 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
 	is->is_timeout = 0;
 	ISCSI_SESSION_UNLOCK(is);
 	cv_signal(&is->is_softc->sc_cv);
 }
 
 static void
 iscsi_maintenance_thread_terminate(struct iscsi_session *is)
 {
 	struct iscsi_softc *sc;
 
 	sc = is->is_softc;
 	sx_xlock(&sc->sc_lock);
 	TAILQ_REMOVE(&sc->sc_sessions, is, is_next);
 	sx_xunlock(&sc->sc_lock);
 
 	icl_conn_close(is->is_conn);
 	callout_drain(&is->is_callout);
 
 	ISCSI_SESSION_LOCK(is);
 
 	KASSERT(is->is_terminating, ("is_terminating == false"));
 
 #ifdef ICL_KERNEL_PROXY
 	if (is->is_login_pdu != NULL) {
 		icl_pdu_free(is->is_login_pdu);
 		is->is_login_pdu = NULL;
 	}
 	cv_signal(&is->is_login_cv);
 #endif
 
 	iscsi_session_cleanup(is, true);
 
 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
 	    ("destroying session with active tasks"));
 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
 	    ("destroying session with postponed PDUs"));
 
 	ISCSI_SESSION_UNLOCK(is);
 
 	icl_conn_free(is->is_conn);
 	mtx_destroy(&is->is_lock);
 	cv_destroy(&is->is_maintenance_cv);
 #ifdef ICL_KERNEL_PROXY
 	cv_destroy(&is->is_login_cv);
 #endif
 
 	ISCSI_SESSION_DEBUG(is, "terminated");
 	free(is, M_ISCSI);
 
 	/*
 	 * The iscsi_unload() routine might be waiting.
 	 */
 	cv_signal(&sc->sc_cv);
 }
 
 static void
 iscsi_maintenance_thread(void *arg)
 {
 	struct iscsi_session *is = arg;
 
 	ISCSI_SESSION_LOCK(is);
 	for (;;) {
 		if (is->is_reconnecting == false &&
 		    is->is_terminating == false &&
 		    (STAILQ_EMPTY(&is->is_postponed) ||
 		     ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn)))
 			cv_wait(&is->is_maintenance_cv, &is->is_lock);
 
 		/* Terminate supersedes reconnect. */
 		if (is->is_terminating) {
 			ISCSI_SESSION_UNLOCK(is);
 			iscsi_maintenance_thread_terminate(is);
 			kthread_exit();
 			return;
 		}
 
 		if (is->is_reconnecting) {
 			ISCSI_SESSION_UNLOCK(is);
 			iscsi_maintenance_thread_reconnect(is);
 			ISCSI_SESSION_LOCK(is);
 			continue;
 		}
 
 		iscsi_session_send_postponed(is);
 	}
 	ISCSI_SESSION_UNLOCK(is);
 }
 
 static void
 iscsi_session_reconnect(struct iscsi_session *is)
 {
 
 	/*
 	 * XXX: We can't use locking here, because
 	 * 	it's being called from various contexts.
 	 * 	Hope it doesn't break anything.
 	 */
 	if (is->is_reconnecting)
 		return;
 
 	is->is_reconnecting = true;
 	cv_signal(&is->is_maintenance_cv);
 }
 
 static void
 iscsi_session_terminate(struct iscsi_session *is)
 {
 
 	if (is->is_terminating)
 		return;
 
 	is->is_terminating = true;
 
 #if 0
 	iscsi_session_logout(is);
 #endif
 	cv_signal(&is->is_maintenance_cv);
 }
 
 static void
 iscsi_callout(void *context)
 {
 	struct icl_pdu *request;
 	struct iscsi_bhs_nop_out *bhsno;
 	struct iscsi_session *is;
 	bool reconnect_needed = false;
 
 	is = context;
 
 	ISCSI_SESSION_LOCK(is);
 	if (is->is_terminating) {
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 
 	callout_schedule(&is->is_callout, 1 * hz);
 
 	if (is->is_conf.isc_enable == 0)
 		goto out;
 
 	is->is_timeout++;
 
 	if (is->is_waiting_for_iscsid) {
 		if (iscsid_timeout > 0 && is->is_timeout > iscsid_timeout) {
 			ISCSI_SESSION_WARN(is, "timed out waiting for iscsid(8) "
 			    "for %d seconds; reconnecting",
 			    is->is_timeout);
 			reconnect_needed = true;
 		}
 		goto out;
 	}
 
 	if (is->is_login_phase) {
 		if (login_timeout > 0 && is->is_timeout > login_timeout) {
 			ISCSI_SESSION_WARN(is, "login timed out after %d seconds; "
 			    "reconnecting", is->is_timeout);
 			reconnect_needed = true;
 		}
 		goto out;
 	}
 
 	if (ping_timeout <= 0) {
 		/*
 		 * Pings are disabled.  Don't send NOP-Out in this case.
 		 * Reset the timeout, to avoid triggering reconnection,
 		 * should the user decide to reenable them.
 		 */
 		is->is_timeout = 0;
 		goto out;
 	}
 
 	if (is->is_timeout >= ping_timeout) {
 		ISCSI_SESSION_WARN(is, "no ping reply (NOP-In) after %d seconds; "
 		    "reconnecting", ping_timeout);
 		reconnect_needed = true;
 		goto out;
 	}
 
 	ISCSI_SESSION_UNLOCK(is);
 
 	/*
 	 * If the ping was reset less than one second ago - which means
 	 * that we've received some PDU during the last second - assume
 	 * the traffic flows correctly and don't bother sending a NOP-Out.
 	 *
 	 * (It's 2 - one for one second, and one for incrementing is_timeout
 	 * earlier in this routine.)
 	 */
 	if (is->is_timeout < 2)
 		return;
 
 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
 	if (request == NULL) {
 		ISCSI_SESSION_WARN(is, "failed to allocate PDU");
 		return;
 	}
 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
 	    ISCSI_BHS_OPCODE_IMMEDIATE;
 	bhsno->bhsno_flags = 0x80;
 	bhsno->bhsno_target_transfer_tag = 0xffffffff;
 	iscsi_pdu_queue(request);
 	return;
 
 out:
 	if (is->is_terminating) {
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 
 	ISCSI_SESSION_UNLOCK(is);
 
 	if (reconnect_needed)
 		iscsi_session_reconnect(is);
 }
 
 static void
 iscsi_pdu_update_statsn(const struct icl_pdu *response)
 {
 	const struct iscsi_bhs_data_in *bhsdi;
 	struct iscsi_session *is;
 	uint32_t expcmdsn, maxcmdsn, statsn;
 
 	is = PDU_SESSION(response);
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	/*
 	 * We're only using fields common for all the response
 	 * (target -> initiator) PDUs.
 	 */
 	bhsdi = (const struct iscsi_bhs_data_in *)response->ip_bhs;
 	/*
 	 * Ok, I lied.  In case of Data-In, "The fields StatSN, Status,
 	 * and Residual Count only have meaningful content if the S bit
 	 * is set to 1", so we also need to check the bit specific for
 	 * Data-In PDU.
 	 */
 	if (bhsdi->bhsdi_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_IN ||
 	    (bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0) {
 		statsn = ntohl(bhsdi->bhsdi_statsn);
 		if (statsn != is->is_statsn && statsn != (is->is_statsn + 1)) {
 			/* XXX: This is normal situation for MCS */
 			ISCSI_SESSION_WARN(is, "PDU 0x%x StatSN %u != "
 			    "session ExpStatSN %u (or + 1); reconnecting",
 			    bhsdi->bhsdi_opcode, statsn, is->is_statsn);
 			iscsi_session_reconnect(is);
 		}
 		if (ISCSI_SNGT(statsn, is->is_statsn))
 			is->is_statsn = statsn;
 	}
 
 	expcmdsn = ntohl(bhsdi->bhsdi_expcmdsn);
 	maxcmdsn = ntohl(bhsdi->bhsdi_maxcmdsn);
 
 	if (ISCSI_SNLT(maxcmdsn + 1, expcmdsn)) {
 		ISCSI_SESSION_DEBUG(is,
 		    "PDU MaxCmdSN %u + 1 < PDU ExpCmdSN %u; ignoring",
 		    maxcmdsn, expcmdsn);
 	} else {
 		if (ISCSI_SNGT(maxcmdsn, is->is_maxcmdsn)) {
 			is->is_maxcmdsn = maxcmdsn;
 
 			/*
 			 * Command window increased; kick the maintanance thread
 			 * to send out postponed commands.
 			 */
 			if (!STAILQ_EMPTY(&is->is_postponed))
 				cv_signal(&is->is_maintenance_cv);
 		} else if (ISCSI_SNLT(maxcmdsn, is->is_maxcmdsn)) {
 			/* XXX: This is normal situation for MCS */
 			ISCSI_SESSION_DEBUG(is,
 			    "PDU MaxCmdSN %u < session MaxCmdSN %u; ignoring",
 			    maxcmdsn, is->is_maxcmdsn);
 		}
 
 		if (ISCSI_SNGT(expcmdsn, is->is_expcmdsn)) {
 			is->is_expcmdsn = expcmdsn;
 		} else if (ISCSI_SNLT(expcmdsn, is->is_expcmdsn)) {
 			/* XXX: This is normal situation for MCS */
 			ISCSI_SESSION_DEBUG(is,
 			    "PDU ExpCmdSN %u < session ExpCmdSN %u; ignoring",
 			    expcmdsn, is->is_expcmdsn);
 		}
 	}
 
 	/*
 	 * Every incoming PDU - not just NOP-In - resets the ping timer.
 	 * The purpose of the timeout is to reset the connection when it stalls;
 	 * we don't want this to happen when NOP-In or NOP-Out ends up delayed
 	 * in some queue.
 	 */
 	is->is_timeout = 0;
 }
 
 static void
 iscsi_receive_callback(struct icl_pdu *response)
 {
 	struct iscsi_session *is;
 
 	is = PDU_SESSION(response);
 
 	ISCSI_SESSION_LOCK(is);
 
 	iscsi_pdu_update_statsn(response);
 
 #ifdef ICL_KERNEL_PROXY
 	if (is->is_login_phase) {
 		if (is->is_login_pdu == NULL)
 			is->is_login_pdu = response;
 		else
 			icl_pdu_free(response);
 		ISCSI_SESSION_UNLOCK(is);
 		cv_signal(&is->is_login_cv);
 		return;
 	}
 #endif
 
 	/*
 	 * The handling routine is responsible for freeing the PDU
 	 * when it's no longer needed.
 	 */
 	switch (response->ip_bhs->bhs_opcode) {
 	case ISCSI_BHS_OPCODE_NOP_IN:
 		iscsi_pdu_handle_nop_in(response);
 		ISCSI_SESSION_UNLOCK(is);
 		break;
 	case ISCSI_BHS_OPCODE_SCSI_RESPONSE:
 		iscsi_pdu_handle_scsi_response(response);
 		/* Session lock dropped inside. */
 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
 		break;
 	case ISCSI_BHS_OPCODE_TASK_RESPONSE:
 		iscsi_pdu_handle_task_response(response);
 		ISCSI_SESSION_UNLOCK(is);
 		break;
 	case ISCSI_BHS_OPCODE_SCSI_DATA_IN:
 		iscsi_pdu_handle_data_in(response);
 		/* Session lock dropped inside. */
 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
 		break;
 	case ISCSI_BHS_OPCODE_LOGOUT_RESPONSE:
 		iscsi_pdu_handle_logout_response(response);
 		ISCSI_SESSION_UNLOCK(is);
 		break;
 	case ISCSI_BHS_OPCODE_R2T:
 		iscsi_pdu_handle_r2t(response);
 		ISCSI_SESSION_UNLOCK(is);
 		break;
 	case ISCSI_BHS_OPCODE_ASYNC_MESSAGE:
 		iscsi_pdu_handle_async_message(response);
 		ISCSI_SESSION_UNLOCK(is);
 		break;
 	case ISCSI_BHS_OPCODE_REJECT:
 		iscsi_pdu_handle_reject(response);
 		ISCSI_SESSION_UNLOCK(is);
 		break;
 	default:
 		ISCSI_SESSION_WARN(is, "received PDU with unsupported "
 		    "opcode 0x%x; reconnecting",
 		    response->ip_bhs->bhs_opcode);
 		iscsi_session_reconnect(is);
 		ISCSI_SESSION_UNLOCK(is);
 		icl_pdu_free(response);
 	}
 }
 
 static void
 iscsi_error_callback(struct icl_conn *ic)
 {
 	struct iscsi_session *is;
 
 	is = CONN_SESSION(ic);
 
 	ISCSI_SESSION_WARN(is, "connection error; reconnecting");
 	iscsi_session_reconnect(is);
 }
 
 static void
 iscsi_pdu_handle_nop_in(struct icl_pdu *response)
 {
 	struct iscsi_session *is;
 	struct iscsi_bhs_nop_out *bhsno;
 	struct iscsi_bhs_nop_in *bhsni;
 	struct icl_pdu *request;
 	void *data = NULL;
 	size_t datasize;
 	int error;
 
 	is = PDU_SESSION(response);
 	bhsni = (struct iscsi_bhs_nop_in *)response->ip_bhs;
 
 	if (bhsni->bhsni_target_transfer_tag == 0xffffffff) {
 		/*
 		 * Nothing to do; iscsi_pdu_update_statsn() already
 		 * zeroed the timeout.
 		 */
 		icl_pdu_free(response);
 		return;
 	}
 
 	datasize = icl_pdu_data_segment_length(response);
 	if (datasize > 0) {
 		data = malloc(datasize, M_ISCSI, M_NOWAIT | M_ZERO);
 		if (data == NULL) {
 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
 			    "reconnecting");
 			icl_pdu_free(response);
 			iscsi_session_reconnect(is);
 			return;
 		}
 		icl_pdu_get_data(response, 0, data, datasize);
 	}
 
 	request = icl_pdu_new(response->ip_conn, M_NOWAIT);
 	if (request == NULL) {
 		ISCSI_SESSION_WARN(is, "failed to allocate memory; "
 		    "reconnecting");
 		free(data, M_ISCSI);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		return;
 	}
 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
 	    ISCSI_BHS_OPCODE_IMMEDIATE;
 	bhsno->bhsno_flags = 0x80;
 	bhsno->bhsno_initiator_task_tag = 0xffffffff;
 	bhsno->bhsno_target_transfer_tag = bhsni->bhsni_target_transfer_tag;
 	if (datasize > 0) {
 		error = icl_pdu_append_data(request, data, datasize, M_NOWAIT);
 		if (error != 0) {
 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
 			    "reconnecting");
 			free(data, M_ISCSI);
 			icl_pdu_free(request);
 			icl_pdu_free(response);
 			iscsi_session_reconnect(is);
 			return;
 		}
 		free(data, M_ISCSI);
 	}
 
 	icl_pdu_free(response);
 	iscsi_pdu_queue_locked(request);
 }
 
 static void
 iscsi_pdu_handle_scsi_response(struct icl_pdu *response)
 {
 	struct iscsi_bhs_scsi_response *bhssr;
 	struct iscsi_outstanding *io;
 	struct iscsi_session *is;
 	union ccb *ccb;
 	struct ccb_scsiio *csio;
 	size_t data_segment_len, received;
 	uint16_t sense_len;
 	uint32_t resid;
 
 	is = PDU_SESSION(response);
 
 	bhssr = (struct iscsi_bhs_scsi_response *)response->ip_bhs;
 	io = iscsi_outstanding_find(is, bhssr->bhssr_initiator_task_tag);
 	if (io == NULL || io->io_ccb == NULL) {
 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhssr->bhssr_initiator_task_tag);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 
 	ccb = io->io_ccb;
-	if (ntohl(bhssr->bhssr_expdatasn) != io->io_datasn) {
-		ISCSI_SESSION_WARN(is,
-		    "ExpDataSN mismatch in SCSI Response (%u vs %u)",
-		    ntohl(bhssr->bhssr_expdatasn), io->io_datasn);
-		icl_pdu_free(response);
-		iscsi_session_reconnect(is);
-		ISCSI_SESSION_UNLOCK(is);
-		return;
+	if (bhssr->bhssr_response == BHSSR_RESPONSE_COMMAND_COMPLETED) {
+		if (ntohl(bhssr->bhssr_expdatasn) != io->io_datasn) {
+			ISCSI_SESSION_WARN(is,
+			    "ExpDataSN mismatch in SCSI Response (%u vs %u)",
+			    ntohl(bhssr->bhssr_expdatasn), io->io_datasn);
+
+			/*
+			 * XXX: Permit an ExpDataSN of zero for errors.
+			 *
+			 * This doesn't conform to RFC 7143, but some
+			 * targets seem to do this.
+			 */
+			if (bhssr->bhssr_status != 0 &&
+			    bhssr->bhssr_expdatasn == htonl(0))
+				goto skip_expdatasn;
+
+			icl_pdu_free(response);
+			iscsi_session_reconnect(is);
+			ISCSI_SESSION_UNLOCK(is);
+			return;
+		}
+	} else {
+		if (bhssr->bhssr_expdatasn != htonl(0)) {
+			ISCSI_SESSION_WARN(is,
+			    "ExpDataSN mismatch in SCSI Response (%u vs 0)",
+			    ntohl(bhssr->bhssr_expdatasn));
+			icl_pdu_free(response);
+			iscsi_session_reconnect(is);
+			ISCSI_SESSION_UNLOCK(is);
+			return;
+		}
 	}
+skip_expdatasn:
 
 	/*
 	 * With iSER, after getting good response we can be sure
 	 * that all the data has been successfully transferred.
 	 */
 	if (is->is_conn->ic_iser) {
 		resid = ntohl(bhssr->bhssr_residual_count);
 		if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW) {
 			io->io_received = ccb->csio.dxfer_len - resid;
 		} else if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_OVERFLOW) {
 			ISCSI_SESSION_WARN(is, "overflow: target indicates %d", resid);
 		} else {
 			io->io_received = ccb->csio.dxfer_len;
 		}
 	}
 
 	received = io->io_received;
 	iscsi_outstanding_remove(is, io);
 	ISCSI_SESSION_UNLOCK(is);
 
 	if (bhssr->bhssr_response != BHSSR_RESPONSE_COMMAND_COMPLETED) {
 		ISCSI_SESSION_WARN(is, "service response 0x%x", bhssr->bhssr_response);
  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
  			xpt_freeze_devq(ccb->ccb_h.path, 1);
 			ISCSI_SESSION_DEBUG(is, "freezing devq");
 		}
  		ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
 	} else if (bhssr->bhssr_status == 0) {
 		ccb->ccb_h.status = CAM_REQ_CMP;
 	} else {
  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
  			xpt_freeze_devq(ccb->ccb_h.path, 1);
 			ISCSI_SESSION_DEBUG(is, "freezing devq");
 		}
  		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
 		ccb->csio.scsi_status = bhssr->bhssr_status;
 	}
 
 	csio = &ccb->csio;
 	data_segment_len = icl_pdu_data_segment_length(response);
 	if (data_segment_len > 0) {
 		if (data_segment_len < sizeof(sense_len)) {
 			ISCSI_SESSION_WARN(is, "truncated data segment (%zd bytes)",
 			    data_segment_len);
 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 				xpt_freeze_devq(ccb->ccb_h.path, 1);
 				ISCSI_SESSION_DEBUG(is, "freezing devq");
 			}
 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
 			goto out;
 		}
 		icl_pdu_get_data(response, 0, &sense_len, sizeof(sense_len));
 		sense_len = ntohs(sense_len);
 #if 0
 		ISCSI_SESSION_DEBUG(is, "sense_len %d, data len %zd",
 		    sense_len, data_segment_len);
 #endif
 		if (sizeof(sense_len) + sense_len > data_segment_len) {
 			ISCSI_SESSION_WARN(is, "truncated data segment "
 			    "(%zd bytes, should be %zd)",
 			    data_segment_len, sizeof(sense_len) + sense_len);
 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 				xpt_freeze_devq(ccb->ccb_h.path, 1);
 				ISCSI_SESSION_DEBUG(is, "freezing devq");
 			}
 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
 			goto out;
 		} else if (sizeof(sense_len) + sense_len < data_segment_len)
 			ISCSI_SESSION_WARN(is, "oversize data segment "
 			    "(%zd bytes, should be %zd)",
 			    data_segment_len, sizeof(sense_len) + sense_len);
 		if (sense_len > csio->sense_len) {
 			ISCSI_SESSION_DEBUG(is, "truncating sense from %d to %d",
 			    sense_len, csio->sense_len);
 			sense_len = csio->sense_len;
 		}
 		icl_pdu_get_data(response, sizeof(sense_len), &csio->sense_data, sense_len);
 		csio->sense_resid = csio->sense_len - sense_len;
 		ccb->ccb_h.status |= CAM_AUTOSNS_VALID;
 	}
 
 out:
 	if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW)
 		csio->resid = ntohl(bhssr->bhssr_residual_count);
 
 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
 		KASSERT(received <= csio->dxfer_len,
 		    ("received > csio->dxfer_len"));
 		if (received < csio->dxfer_len) {
 			if (csio->resid != csio->dxfer_len - received) {
 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
 				    "target indicates %d, we calculated %zd",
 				    csio->resid, csio->dxfer_len - received);
 			}
 			csio->resid = csio->dxfer_len - received;
 		}
 	}
 
 	xpt_done(ccb);
 	icl_pdu_free(response);
 }
 
 static void
 iscsi_pdu_handle_task_response(struct icl_pdu *response)
 {
 	struct iscsi_bhs_task_management_response *bhstmr;
 	struct iscsi_outstanding *io, *aio;
 	struct iscsi_session *is;
 
 	is = PDU_SESSION(response);
 
 	bhstmr = (struct iscsi_bhs_task_management_response *)response->ip_bhs;
 	io = iscsi_outstanding_find(is, bhstmr->bhstmr_initiator_task_tag);
 	if (io == NULL || io->io_ccb != NULL) {
 		ISCSI_SESSION_WARN(is, "bad itt 0x%x",
 		    bhstmr->bhstmr_initiator_task_tag);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		return;
 	}
 
 	if (bhstmr->bhstmr_response != BHSTMR_RESPONSE_FUNCTION_COMPLETE) {
 		ISCSI_SESSION_WARN(is, "task response 0x%x",
 		    bhstmr->bhstmr_response);
 	} else {
 		aio = iscsi_outstanding_find(is, io->io_referenced_task_tag);
 		if (aio != NULL && aio->io_ccb != NULL)
 			iscsi_session_terminate_task(is, aio, CAM_REQ_ABORTED);
 	}
 
 	iscsi_outstanding_remove(is, io);
 	icl_pdu_free(response);
 }
 
 static void
 iscsi_pdu_handle_data_in(struct icl_pdu *response)
 {
 	struct iscsi_bhs_data_in *bhsdi;
 	struct iscsi_outstanding *io;
 	struct iscsi_session *is;
 	union ccb *ccb;
 	struct ccb_scsiio *csio;
 	size_t data_segment_len, received, oreceived;
 
 	is = PDU_SESSION(response);
 	bhsdi = (struct iscsi_bhs_data_in *)response->ip_bhs;
 	io = iscsi_outstanding_find(is, bhsdi->bhsdi_initiator_task_tag);
 	if (io == NULL || io->io_ccb == NULL) {
 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhsdi->bhsdi_initiator_task_tag);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 
 	if (io->io_datasn != ntohl(bhsdi->bhsdi_datasn)) {
 		ISCSI_SESSION_WARN(is, "received Data-In PDU with "
 		    "DataSN %u, while expected %u; dropping connection",
 		    ntohl(bhsdi->bhsdi_datasn), io->io_datasn);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 	io->io_datasn += response->ip_additional_pdus + 1;
 
 	data_segment_len = icl_pdu_data_segment_length(response);
 	if (data_segment_len == 0) {
 		/*
 		 * "The sending of 0 length data segments should be avoided,
 		 * but initiators and targets MUST be able to properly receive
 		 * 0 length data segments."
 		 */
 		ISCSI_SESSION_UNLOCK(is);
 		icl_pdu_free(response);
 		return;
 	}
 
 	/*
 	 * We need to track this for security reasons - without it, malicious target
 	 * could respond to SCSI READ without sending Data-In PDUs, which would result
 	 * in read operation on the initiator side returning random kernel data.
 	 */
 	if (ntohl(bhsdi->bhsdi_buffer_offset) != io->io_received) {
 		ISCSI_SESSION_WARN(is, "data out of order; expected offset %zd, got %zd",
 		    io->io_received, (size_t)ntohl(bhsdi->bhsdi_buffer_offset));
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 
 	ccb = io->io_ccb;
 	csio = &ccb->csio;
 
 	if (io->io_received + data_segment_len > csio->dxfer_len) {
 		ISCSI_SESSION_WARN(is, "oversize data segment (%zd bytes "
 		    "at offset %zd, buffer is %d)",
 		    data_segment_len, io->io_received, csio->dxfer_len);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		ISCSI_SESSION_UNLOCK(is);
 		return;
 	}
 
 	oreceived = io->io_received;
 	io->io_received += data_segment_len;
 	received = io->io_received;
 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0)
 		iscsi_outstanding_remove(is, io);
 	ISCSI_SESSION_UNLOCK(is);
 
 	icl_pdu_get_data(response, 0, csio->data_ptr + oreceived, data_segment_len);
 
 	/*
 	 * XXX: Check F.
 	 */
 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) == 0) {
 		/*
 		 * Nothing more to do.
 		 */
 		icl_pdu_free(response);
 		return;
 	}
 
 	//ISCSI_SESSION_DEBUG(is, "got S flag; status 0x%x", bhsdi->bhsdi_status);
 	if (bhsdi->bhsdi_status == 0) {
 		ccb->ccb_h.status = CAM_REQ_CMP;
 	} else {
 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 			xpt_freeze_devq(ccb->ccb_h.path, 1);
 			ISCSI_SESSION_DEBUG(is, "freezing devq");
 		}
 		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
 		csio->scsi_status = bhsdi->bhsdi_status;
 	}
 
 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
 		KASSERT(received <= csio->dxfer_len,
 		    ("received > csio->dxfer_len"));
 		if (received < csio->dxfer_len) {
 			csio->resid = ntohl(bhsdi->bhsdi_residual_count);
 			if (csio->resid != csio->dxfer_len - received) {
 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
 				    "target indicates %d, we calculated %zd",
 				    csio->resid, csio->dxfer_len - received);
 			}
 			csio->resid = csio->dxfer_len - received;
 		}
 	}
 
 	xpt_done(ccb);
 	icl_pdu_free(response);
 }
 
 static void
 iscsi_pdu_handle_logout_response(struct icl_pdu *response)
 {
 
 	ISCSI_SESSION_DEBUG(PDU_SESSION(response), "logout response");
 	icl_pdu_free(response);
 }
 
 static void
 iscsi_pdu_handle_r2t(struct icl_pdu *response)
 {
 	struct icl_pdu *request;
 	struct iscsi_session *is;
 	struct iscsi_bhs_r2t *bhsr2t;
 	struct iscsi_bhs_data_out *bhsdo;
 	struct iscsi_outstanding *io;
 	struct ccb_scsiio *csio;
 	size_t off, len, max_send_data_segment_length, total_len;
 	int error;
 	uint32_t datasn = 0;
 
 	is = PDU_SESSION(response);
 
 	bhsr2t = (struct iscsi_bhs_r2t *)response->ip_bhs;
 	io = iscsi_outstanding_find(is, bhsr2t->bhsr2t_initiator_task_tag);
 	if (io == NULL || io->io_ccb == NULL) {
 		ISCSI_SESSION_WARN(is, "bad itt 0x%x; reconnecting",
 		    bhsr2t->bhsr2t_initiator_task_tag);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		return;
 	}
 
 	csio = &io->io_ccb->csio;
 
 	if ((csio->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_OUT) {
 		ISCSI_SESSION_WARN(is, "received R2T for read command; reconnecting");
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		return;
 	}
 
 	/*
 	 * XXX: Verify R2TSN.
 	 */
 
 	off = ntohl(bhsr2t->bhsr2t_buffer_offset);
 	if (off > csio->dxfer_len) {
 		ISCSI_SESSION_WARN(is, "target requested invalid offset "
 		    "%zd, buffer is is %d; reconnecting", off, csio->dxfer_len);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		return;
 	}
 
 	total_len = ntohl(bhsr2t->bhsr2t_desired_data_transfer_length);
 	if (total_len == 0 || total_len > csio->dxfer_len) {
 		ISCSI_SESSION_WARN(is, "target requested invalid length "
 		    "%zd, buffer is %d; reconnecting", total_len, csio->dxfer_len);
 		icl_pdu_free(response);
 		iscsi_session_reconnect(is);
 		return;
 	}
 
 	//ISCSI_SESSION_DEBUG(is, "r2t; off %zd, len %zd", off, total_len);
 
 	if (is->is_conn->ic_hw_isomax != 0)
 		max_send_data_segment_length = is->is_conn->ic_hw_isomax;
 	else
 		max_send_data_segment_length =
 		    is->is_conn->ic_max_send_data_segment_length;
 	for (;;) {
 		len = total_len;
 
 		if (len > max_send_data_segment_length)
 			len = max_send_data_segment_length;
 
 		if (off + len > csio->dxfer_len) {
 			ISCSI_SESSION_WARN(is, "target requested invalid "
 			    "length/offset %zd, buffer is %d; reconnecting",
 			    off + len, csio->dxfer_len);
 			icl_pdu_free(response);
 			iscsi_session_reconnect(is);
 			return;
 		}
 
 		request = icl_pdu_new(response->ip_conn, M_NOWAIT);
 		if (request == NULL) {
 			icl_pdu_free(response);
 			iscsi_session_reconnect(is);
 			return;
 		}
 
 		bhsdo = (struct iscsi_bhs_data_out *)request->ip_bhs;
 		bhsdo->bhsdo_opcode = ISCSI_BHS_OPCODE_SCSI_DATA_OUT;
 		bhsdo->bhsdo_lun = bhsr2t->bhsr2t_lun;
 		bhsdo->bhsdo_initiator_task_tag =
 		    bhsr2t->bhsr2t_initiator_task_tag;
 		bhsdo->bhsdo_target_transfer_tag =
 		    bhsr2t->bhsr2t_target_transfer_tag;
 		bhsdo->bhsdo_datasn = htonl(datasn);
 		bhsdo->bhsdo_buffer_offset = htonl(off);
 		error = icl_pdu_append_data(request, csio->data_ptr + off, len,
 		    M_NOWAIT);
 		if (error != 0) {
 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
 			    "reconnecting");
 			icl_pdu_free(request);
 			icl_pdu_free(response);
 			iscsi_session_reconnect(is);
 			return;
 		}
 
 		datasn += howmany(len,
 		    is->is_conn->ic_max_send_data_segment_length);
 		off += len;
 		total_len -= len;
 
 		if (total_len == 0) {
 			bhsdo->bhsdo_flags |= BHSDO_FLAGS_F;
 			//ISCSI_SESSION_DEBUG(is, "setting F, off %zd", off);
 		} else {
 			//ISCSI_SESSION_DEBUG(is, "not finished, off %zd", off);
 		}
 
 		iscsi_pdu_queue_locked(request);
 
 		if (total_len == 0)
 			break;
 	}
 
 	icl_pdu_free(response);
 }
 
 static void
 iscsi_pdu_handle_async_message(struct icl_pdu *response)
 {
 	struct iscsi_bhs_asynchronous_message *bhsam;
 	struct iscsi_session *is;
 
 	is = PDU_SESSION(response);
 	bhsam = (struct iscsi_bhs_asynchronous_message *)response->ip_bhs;
 	switch (bhsam->bhsam_async_event) {
 	case BHSAM_EVENT_TARGET_REQUESTS_LOGOUT:
 		ISCSI_SESSION_WARN(is, "target requests logout; removing session");
 		iscsi_session_logout(is);
 		iscsi_session_terminate(is);
 		break;
 	case BHSAM_EVENT_TARGET_TERMINATES_CONNECTION:
 		ISCSI_SESSION_WARN(is, "target indicates it will drop the connection");
 		break;
 	case BHSAM_EVENT_TARGET_TERMINATES_SESSION:
 		ISCSI_SESSION_WARN(is, "target indicates it will drop the session");
 		break;
 	default:
 		/*
 		 * XXX: Technically, we're obligated to also handle
 		 * 	parameter renegotiation.
 		 */
 		ISCSI_SESSION_WARN(is, "ignoring AsyncEvent %d", bhsam->bhsam_async_event);
 		break;
 	}
 
 	icl_pdu_free(response);
 }
 
 static void
 iscsi_pdu_handle_reject(struct icl_pdu *response)
 {
 	struct iscsi_bhs_reject *bhsr;
 	struct iscsi_session *is;
 
 	is = PDU_SESSION(response);
 	bhsr = (struct iscsi_bhs_reject *)response->ip_bhs;
 	ISCSI_SESSION_WARN(is, "received Reject PDU, reason 0x%x; protocol error?",
 	    bhsr->bhsr_reason);
 
 	icl_pdu_free(response);
 }
 
 static int
 iscsi_ioctl_daemon_wait(struct iscsi_softc *sc,
     struct iscsi_daemon_request *request)
 {
 	struct iscsi_session *is;
 	struct icl_drv_limits idl;
 	int error;
 
 	sx_slock(&sc->sc_lock);
 	for (;;) {
 		TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 			ISCSI_SESSION_LOCK(is);
 			if (is->is_conf.isc_enable == 0 &&
 			    is->is_conf.isc_discovery == 0) {
 				ISCSI_SESSION_UNLOCK(is);
 				continue;
 			}
 			if (is->is_waiting_for_iscsid)
 				break;
 			ISCSI_SESSION_UNLOCK(is);
 		}
 
 		if (is == NULL) {
 			if (sc->sc_unloading) {
 				sx_sunlock(&sc->sc_lock);
 				return (ENXIO);
 			}
 
 			/*
 			 * No session requires attention from iscsid(8); wait.
 			 */
 			error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
 			if (error != 0) {
 				sx_sunlock(&sc->sc_lock);
 				return (error);
 			}
 			continue;
 		}
 
 		is->is_waiting_for_iscsid = false;
 		is->is_login_phase = true;
 		is->is_reason[0] = '\0';
 		ISCSI_SESSION_UNLOCK(is);
 
 		request->idr_session_id = is->is_id;
 		memcpy(&request->idr_isid, &is->is_isid,
 		    sizeof(request->idr_isid));
 		request->idr_tsih = 0;	/* New or reinstated session. */
 		memcpy(&request->idr_conf, &is->is_conf,
 		    sizeof(request->idr_conf));
 
 		error = icl_limits(is->is_conf.isc_offload,
 		    is->is_conf.isc_iser, &idl);
 		if (error != 0) {
 			ISCSI_SESSION_WARN(is, "icl_limits for offload \"%s\" "
 			    "failed with error %d", is->is_conf.isc_offload,
 			    error);
 			sx_sunlock(&sc->sc_lock);
 			return (error);
 		}
 		request->idr_limits.isl_max_recv_data_segment_length =
 		    idl.idl_max_recv_data_segment_length;
 		request->idr_limits.isl_max_send_data_segment_length =
 		    idl.idl_max_send_data_segment_length;
 		request->idr_limits.isl_max_burst_length =
 		    idl.idl_max_burst_length;
 		request->idr_limits.isl_first_burst_length =
 		    idl.idl_first_burst_length;
 
 		sx_sunlock(&sc->sc_lock);
 		return (0);
 	}
 }
 
 static int
 iscsi_ioctl_daemon_handoff(struct iscsi_softc *sc,
     struct iscsi_daemon_handoff *handoff)
 {
 	struct iscsi_session *is;
 	struct icl_conn *ic;
 	int error;
 
 	sx_slock(&sc->sc_lock);
 
 	/*
 	 * Find the session to hand off socket to.
 	 */
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		if (is->is_id == handoff->idh_session_id)
 			break;
 	}
 	if (is == NULL) {
 		sx_sunlock(&sc->sc_lock);
 		return (ESRCH);
 	}
 	ISCSI_SESSION_LOCK(is);
 	ic = is->is_conn;
 	if (is->is_conf.isc_discovery || is->is_terminating) {
 		ISCSI_SESSION_UNLOCK(is);
 		sx_sunlock(&sc->sc_lock);
 		return (EINVAL);
 	}
 	if (is->is_connected) {
 		/*
 		 * This might have happened because another iscsid(8)
 		 * instance handed off the connection in the meantime.
 		 * Just return.
 		 */
 		ISCSI_SESSION_WARN(is, "handoff on already connected "
 		    "session");
 		ISCSI_SESSION_UNLOCK(is);
 		sx_sunlock(&sc->sc_lock);
 		return (EBUSY);
 	}
 
 	strlcpy(is->is_target_alias, handoff->idh_target_alias,
 	    sizeof(is->is_target_alias));
 	is->is_tsih = handoff->idh_tsih;
 	is->is_statsn = handoff->idh_statsn;
 	is->is_protocol_level = handoff->idh_protocol_level;
 	is->is_initial_r2t = handoff->idh_initial_r2t;
 	is->is_immediate_data = handoff->idh_immediate_data;
 
 	ic->ic_max_recv_data_segment_length =
 	    handoff->idh_max_recv_data_segment_length;
 	ic->ic_max_send_data_segment_length =
 	    handoff->idh_max_send_data_segment_length;
 	is->is_max_burst_length = handoff->idh_max_burst_length;
 	is->is_first_burst_length = handoff->idh_first_burst_length;
 
 	if (handoff->idh_header_digest == ISCSI_DIGEST_CRC32C)
 		ic->ic_header_crc32c = true;
 	else
 		ic->ic_header_crc32c = false;
 	if (handoff->idh_data_digest == ISCSI_DIGEST_CRC32C)
 		ic->ic_data_crc32c = true;
 	else
 		ic->ic_data_crc32c = false;
 	ic->ic_maxtags = maxtags;
 
 	is->is_cmdsn = 0;
 	is->is_expcmdsn = 0;
 	is->is_maxcmdsn = 0;
 	is->is_waiting_for_iscsid = false;
 	is->is_login_phase = false;
 	is->is_timeout = 0;
 	is->is_connected = true;
 	is->is_reason[0] = '\0';
 
 	ISCSI_SESSION_UNLOCK(is);
 
 	/*
 	 * If we're going through the proxy, the idh_socket will be 0,
 	 * and the ICL module can simply ignore this call.  It can also
 	 * use it to determine it's no longer in the Login phase.
 	 */
 	error = icl_conn_handoff(ic, handoff->idh_socket);
 	if (error != 0) {
 		sx_sunlock(&sc->sc_lock);
 		iscsi_session_terminate(is);
 		return (error);
 	}
 
 	sx_sunlock(&sc->sc_lock);
 
 	if (is->is_sim != NULL) {
 		/*
 		 * When reconnecting, there already is SIM allocated for the session.
 		 */
 		KASSERT(is->is_simq_frozen, ("reconnect without frozen simq"));
 		ISCSI_SESSION_LOCK(is);
 		ISCSI_SESSION_DEBUG(is, "releasing");
 		is->is_simq_frozen = false;
 		xpt_release_simq(is->is_sim, 1);
 		ISCSI_SESSION_UNLOCK(is);
 
 	} else {
 		ISCSI_SESSION_LOCK(is);
 		is->is_devq = cam_simq_alloc(ic->ic_maxtags);
 		if (is->is_devq == NULL) {
 			ISCSI_SESSION_WARN(is, "failed to allocate simq");
 			iscsi_session_terminate(is);
 			return (ENOMEM);
 		}
 
 		is->is_sim = cam_sim_alloc(iscsi_action, NULL, "iscsi",
 		    is, is->is_id /* unit */, &is->is_lock,
 		    1, ic->ic_maxtags, is->is_devq);
 		if (is->is_sim == NULL) {
 			ISCSI_SESSION_UNLOCK(is);
 			ISCSI_SESSION_WARN(is, "failed to allocate SIM");
 			cam_simq_free(is->is_devq);
 			iscsi_session_terminate(is);
 			return (ENOMEM);
 		}
 
 		error = xpt_bus_register(is->is_sim, NULL, 0);
 		if (error != 0) {
 			ISCSI_SESSION_UNLOCK(is);
 			ISCSI_SESSION_WARN(is, "failed to register bus");
 			iscsi_session_terminate(is);
 			return (ENOMEM);
 		}
 
 		error = xpt_create_path(&is->is_path, /*periph*/NULL,
 		    cam_sim_path(is->is_sim), CAM_TARGET_WILDCARD,
 		    CAM_LUN_WILDCARD);
 		if (error != CAM_REQ_CMP) {
 			ISCSI_SESSION_UNLOCK(is);
 			ISCSI_SESSION_WARN(is, "failed to create path");
 			iscsi_session_terminate(is);
 			return (ENOMEM);
 		}
 		ISCSI_SESSION_UNLOCK(is);
 	}
 
 	return (0);
 }
 
 static int
 iscsi_ioctl_daemon_fail(struct iscsi_softc *sc,
     struct iscsi_daemon_fail *fail)
 {
 	struct iscsi_session *is;
 
 	sx_slock(&sc->sc_lock);
 
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		if (is->is_id == fail->idf_session_id)
 			break;
 	}
 	if (is == NULL) {
 		sx_sunlock(&sc->sc_lock);
 		return (ESRCH);
 	}
 	ISCSI_SESSION_LOCK(is);
 	ISCSI_SESSION_DEBUG(is, "iscsid(8) failed: %s",
 	    fail->idf_reason);
 	strlcpy(is->is_reason, fail->idf_reason, sizeof(is->is_reason));
 	//is->is_waiting_for_iscsid = false;
 	//is->is_login_phase = true;
 	//iscsi_session_reconnect(is);
 	ISCSI_SESSION_UNLOCK(is);
 	sx_sunlock(&sc->sc_lock);
 
 	return (0);
 }
 
 #ifdef ICL_KERNEL_PROXY
 static int
 iscsi_ioctl_daemon_connect(struct iscsi_softc *sc,
     struct iscsi_daemon_connect *idc)
 {
 	struct iscsi_session *is;
 	struct sockaddr *from_sa, *to_sa;
 	int error;
 
 	sx_slock(&sc->sc_lock);
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		if (is->is_id == idc->idc_session_id)
 			break;
 	}
 	if (is == NULL) {
 		sx_sunlock(&sc->sc_lock);
 		return (ESRCH);
 	}
 	sx_sunlock(&sc->sc_lock);
 
 	if (idc->idc_from_addrlen > 0) {
 		error = getsockaddr(&from_sa, (void *)idc->idc_from_addr, idc->idc_from_addrlen);
 		if (error != 0) {
 			ISCSI_SESSION_WARN(is,
 			    "getsockaddr failed with error %d", error);
 			return (error);
 		}
 	} else {
 		from_sa = NULL;
 	}
 	error = getsockaddr(&to_sa, (void *)idc->idc_to_addr, idc->idc_to_addrlen);
 	if (error != 0) {
 		ISCSI_SESSION_WARN(is, "getsockaddr failed with error %d",
 		    error);
 		free(from_sa, M_SONAME);
 		return (error);
 	}
 
 	ISCSI_SESSION_LOCK(is);
 	is->is_statsn = 0;
 	is->is_cmdsn = 0;
 	is->is_expcmdsn = 0;
 	is->is_maxcmdsn = 0;
 	is->is_waiting_for_iscsid = false;
 	is->is_login_phase = true;
 	is->is_timeout = 0;
 	ISCSI_SESSION_UNLOCK(is);
 
 	error = icl_conn_connect(is->is_conn, idc->idc_domain,
 	    idc->idc_socktype, idc->idc_protocol, from_sa, to_sa);
 	free(from_sa, M_SONAME);
 	free(to_sa, M_SONAME);
 
 	/*
 	 * Digests are always disabled during login phase.
 	 */
 	is->is_conn->ic_header_crc32c = false;
 	is->is_conn->ic_data_crc32c = false;
 
 	return (error);
 }
 
 static int
 iscsi_ioctl_daemon_send(struct iscsi_softc *sc,
     struct iscsi_daemon_send *ids)
 {
 	struct iscsi_session *is;
 	struct icl_pdu *ip;
 	size_t datalen;
 	void *data;
 	int error;
 
 	sx_slock(&sc->sc_lock);
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		if (is->is_id == ids->ids_session_id)
 			break;
 	}
 	if (is == NULL) {
 		sx_sunlock(&sc->sc_lock);
 		return (ESRCH);
 	}
 	sx_sunlock(&sc->sc_lock);
 
 	if (is->is_login_phase == false)
 		return (EBUSY);
 
 	if (is->is_terminating || is->is_reconnecting)
 		return (EIO);
 
 	datalen = ids->ids_data_segment_len;
 	if (datalen > is->is_conn->ic_max_send_data_segment_length)
 		return (EINVAL);
 	if (datalen > 0) {
 		data = malloc(datalen, M_ISCSI, M_WAITOK);
 		error = copyin(ids->ids_data_segment, data, datalen);
 		if (error != 0) {
 			free(data, M_ISCSI);
 			return (error);
 		}
 	}
 
 	ip = icl_pdu_new(is->is_conn, M_WAITOK);
 	memcpy(ip->ip_bhs, ids->ids_bhs, sizeof(*ip->ip_bhs));
 	if (datalen > 0) {
 		error = icl_pdu_append_data(ip, data, datalen, M_WAITOK);
 		KASSERT(error == 0, ("icl_pdu_append_data(..., M_WAITOK) failed"));
 		free(data, M_ISCSI);
 	}
 	iscsi_pdu_queue(ip);
 
 	return (0);
 }
 
 static int
 iscsi_ioctl_daemon_receive(struct iscsi_softc *sc,
     struct iscsi_daemon_receive *idr)
 {
 	struct iscsi_session *is;
 	struct icl_pdu *ip;
 	void *data;
 	int error;
 
 	sx_slock(&sc->sc_lock);
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		if (is->is_id == idr->idr_session_id)
 			break;
 	}
 	if (is == NULL) {
 		sx_sunlock(&sc->sc_lock);
 		return (ESRCH);
 	}
 	sx_sunlock(&sc->sc_lock);
 
 	if (is->is_login_phase == false)
 		return (EBUSY);
 
 	ISCSI_SESSION_LOCK(is);
 	while (is->is_login_pdu == NULL &&
 	    is->is_terminating == false &&
 	    is->is_reconnecting == false) {
 		error = cv_wait_sig(&is->is_login_cv, &is->is_lock);
 		if (error != 0) {
 			ISCSI_SESSION_UNLOCK(is);
 			return (error);
 		}
 	}
 	if (is->is_terminating || is->is_reconnecting) {
 		ISCSI_SESSION_UNLOCK(is);
 		return (EIO);
 	}
 	ip = is->is_login_pdu;
 	is->is_login_pdu = NULL;
 	ISCSI_SESSION_UNLOCK(is);
 
 	if (ip->ip_data_len > idr->idr_data_segment_len) {
 		icl_pdu_free(ip);
 		return (EMSGSIZE);
 	}
 
 	copyout(ip->ip_bhs, idr->idr_bhs, sizeof(*ip->ip_bhs));
 	if (ip->ip_data_len > 0) {
 		data = malloc(ip->ip_data_len, M_ISCSI, M_WAITOK);
 		icl_pdu_get_data(ip, 0, data, ip->ip_data_len);
 		copyout(data, idr->idr_data_segment, ip->ip_data_len);
 		free(data, M_ISCSI);
 	}
 
 	icl_pdu_free(ip);
 
 	return (0);
 }
 #endif /* ICL_KERNEL_PROXY */
 
 static void
 iscsi_sanitize_session_conf(struct iscsi_session_conf *isc)
 {
 	/*
 	 * Just make sure all the fields are null-terminated.
 	 *
 	 * XXX: This is not particularly secure.  We should
 	 * 	create our own conf and then copy in relevant
 	 * 	fields.
 	 */
 	isc->isc_initiator[ISCSI_NAME_LEN - 1] = '\0';
 	isc->isc_initiator_addr[ISCSI_ADDR_LEN - 1] = '\0';
 	isc->isc_initiator_alias[ISCSI_ALIAS_LEN - 1] = '\0';
 	isc->isc_target[ISCSI_NAME_LEN - 1] = '\0';
 	isc->isc_target_addr[ISCSI_ADDR_LEN - 1] = '\0';
 	isc->isc_user[ISCSI_NAME_LEN - 1] = '\0';
 	isc->isc_secret[ISCSI_SECRET_LEN - 1] = '\0';
 	isc->isc_mutual_user[ISCSI_NAME_LEN - 1] = '\0';
 	isc->isc_mutual_secret[ISCSI_SECRET_LEN - 1] = '\0';
 }
 
 static bool
 iscsi_valid_session_conf(const struct iscsi_session_conf *isc)
 {
 
 	if (isc->isc_initiator[0] == '\0') {
 		ISCSI_DEBUG("empty isc_initiator");
 		return (false);
 	}
 
 	if (isc->isc_target_addr[0] == '\0') {
 		ISCSI_DEBUG("empty isc_target_addr");
 		return (false);
 	}
 
 	if (isc->isc_discovery != 0 && isc->isc_target[0] != 0) {
 		ISCSI_DEBUG("non-empty isc_target for discovery session");
 		return (false);
 	}
 
 	if (isc->isc_discovery == 0 && isc->isc_target[0] == 0) {
 		ISCSI_DEBUG("empty isc_target for non-discovery session");
 		return (false);
 	}
 
 	return (true);
 }
 
 static int
 iscsi_ioctl_session_add(struct iscsi_softc *sc, struct iscsi_session_add *isa)
 {
 	struct iscsi_session *is;
 	const struct iscsi_session *is2;
 	int error;
 
 	iscsi_sanitize_session_conf(&isa->isa_conf);
 	if (iscsi_valid_session_conf(&isa->isa_conf) == false)
 		return (EINVAL);
 
 	is = malloc(sizeof(*is), M_ISCSI, M_ZERO | M_WAITOK);
 	memcpy(&is->is_conf, &isa->isa_conf, sizeof(is->is_conf));
 
 	sx_xlock(&sc->sc_lock);
 
 	/*
 	 * Prevent duplicates.
 	 */
 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
 		if (!!is->is_conf.isc_discovery !=
 		    !!is2->is_conf.isc_discovery)
 			continue;
 
 		if (strcmp(is->is_conf.isc_target_addr,
 		    is2->is_conf.isc_target_addr) != 0)
 			continue;
 
 		if (is->is_conf.isc_discovery == 0 &&
 		    strcmp(is->is_conf.isc_target,
 		    is2->is_conf.isc_target) != 0)
 			continue;
 
 		sx_xunlock(&sc->sc_lock);
 		free(is, M_ISCSI);
 		return (EBUSY);
 	}
 
 	is->is_conn = icl_new_conn(is->is_conf.isc_offload,
 	    is->is_conf.isc_iser, "iscsi", &is->is_lock);
 	if (is->is_conn == NULL) {
 		sx_xunlock(&sc->sc_lock);
 		free(is, M_ISCSI);
 		return (EINVAL);
 	}
 	is->is_conn->ic_receive = iscsi_receive_callback;
 	is->is_conn->ic_error = iscsi_error_callback;
 	is->is_conn->ic_prv0 = is;
 	TAILQ_INIT(&is->is_outstanding);
 	STAILQ_INIT(&is->is_postponed);
 	mtx_init(&is->is_lock, "iscsi_lock", NULL, MTX_DEF);
 	cv_init(&is->is_maintenance_cv, "iscsi_mt");
 #ifdef ICL_KERNEL_PROXY
 	cv_init(&is->is_login_cv, "iscsi_login");
 #endif
 
 	/*
 	 * Set some default values, from RFC 3720, section 12.
 	 *
 	 * These values are updated by the handoff IOCTL, but are
 	 * needed prior to the handoff to support sending the ISER
 	 * login PDU.
 	 */
 	is->is_conn->ic_max_recv_data_segment_length = 8192;
 	is->is_conn->ic_max_send_data_segment_length = 8192;
 	is->is_max_burst_length = 262144;
 	is->is_first_burst_length = 65536;
 
 	is->is_softc = sc;
 	sc->sc_last_session_id++;
 	is->is_id = sc->sc_last_session_id;
 	is->is_isid[0] = 0x80; /* RFC 3720, 10.12.5: 10b, "Random" ISID. */
 	arc4rand(&is->is_isid[1], 5, 0);
 	is->is_tsih = 0;
 	callout_init(&is->is_callout, 1);
 
 	error = kthread_add(iscsi_maintenance_thread, is, NULL, NULL, 0, 0, "iscsimt");
 	if (error != 0) {
 		ISCSI_SESSION_WARN(is, "kthread_add(9) failed with error %d", error);
 		sx_xunlock(&sc->sc_lock);
 		return (error);
 	}
 
 	callout_reset(&is->is_callout, 1 * hz, iscsi_callout, is);
 	TAILQ_INSERT_TAIL(&sc->sc_sessions, is, is_next);
 
 	ISCSI_SESSION_LOCK(is);
 	/*
 	 * Don't notify iscsid(8) if the session is disabled and it's not
 	 * a discovery session,
 	 */
 	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
 		ISCSI_SESSION_UNLOCK(is);
 		sx_xunlock(&sc->sc_lock);
 		return (0);
 	}
 
 	is->is_waiting_for_iscsid = true;
 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
 	ISCSI_SESSION_UNLOCK(is);
 	cv_signal(&sc->sc_cv);
 	sx_xunlock(&sc->sc_lock);
 	return (0);
 }
 
 static bool
 iscsi_session_conf_matches(unsigned int id1, const struct iscsi_session_conf *c1,
     unsigned int id2, const struct iscsi_session_conf *c2)
 {
 
 	if (id2 != 0 && id2 != id1)
 		return (false);
 	if (c2->isc_target[0] != '\0' &&
 	    strcmp(c1->isc_target, c2->isc_target) != 0)
 		return (false);
 	if (c2->isc_target_addr[0] != '\0' &&
 	    strcmp(c1->isc_target_addr, c2->isc_target_addr) != 0)
 		return (false);
 	return (true);
 }
 
 static int
 iscsi_ioctl_session_remove(struct iscsi_softc *sc,
     struct iscsi_session_remove *isr)
 {
 	struct iscsi_session *is, *tmp;
 	bool found = false;
 
 	iscsi_sanitize_session_conf(&isr->isr_conf);
 
 	sx_xlock(&sc->sc_lock);
 	TAILQ_FOREACH_SAFE(is, &sc->sc_sessions, is_next, tmp) {
 		ISCSI_SESSION_LOCK(is);
 		if (iscsi_session_conf_matches(is->is_id, &is->is_conf,
 		    isr->isr_session_id, &isr->isr_conf)) {
 			found = true;
 			iscsi_session_logout(is);
 			iscsi_session_terminate(is);
 		}
 		ISCSI_SESSION_UNLOCK(is);
 	}
 	sx_xunlock(&sc->sc_lock);
 
 	if (!found)
 		return (ESRCH);
 
 	return (0);
 }
 
 static int
 iscsi_ioctl_session_list(struct iscsi_softc *sc, struct iscsi_session_list *isl)
 {
 	int error;
 	unsigned int i = 0;
 	struct iscsi_session *is;
 	struct iscsi_session_state iss;
 
 	sx_slock(&sc->sc_lock);
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		if (i >= isl->isl_nentries) {
 			sx_sunlock(&sc->sc_lock);
 			return (EMSGSIZE);
 		}
 		memset(&iss, 0, sizeof(iss));
 		memcpy(&iss.iss_conf, &is->is_conf, sizeof(iss.iss_conf));
 		iss.iss_id = is->is_id;
 		strlcpy(iss.iss_target_alias, is->is_target_alias, sizeof(iss.iss_target_alias));
 		strlcpy(iss.iss_reason, is->is_reason, sizeof(iss.iss_reason));
 		strlcpy(iss.iss_offload, is->is_conn->ic_offload, sizeof(iss.iss_offload));
 
 		if (is->is_conn->ic_header_crc32c)
 			iss.iss_header_digest = ISCSI_DIGEST_CRC32C;
 		else
 			iss.iss_header_digest = ISCSI_DIGEST_NONE;
 
 		if (is->is_conn->ic_data_crc32c)
 			iss.iss_data_digest = ISCSI_DIGEST_CRC32C;
 		else
 			iss.iss_data_digest = ISCSI_DIGEST_NONE;
 
 		iss.iss_max_send_data_segment_length =
 		    is->is_conn->ic_max_send_data_segment_length;
 		iss.iss_max_recv_data_segment_length =
 		    is->is_conn->ic_max_recv_data_segment_length;
 		iss.iss_max_burst_length = is->is_max_burst_length;
 		iss.iss_first_burst_length = is->is_first_burst_length;
 		iss.iss_immediate_data = is->is_immediate_data;
 		iss.iss_connected = is->is_connected;
 
 		error = copyout(&iss, isl->isl_pstates + i, sizeof(iss));
 		if (error != 0) {
 			sx_sunlock(&sc->sc_lock);
 			return (error);
 		}
 		i++;
 	}
 	sx_sunlock(&sc->sc_lock);
 
 	isl->isl_nentries = i;
 
 	return (0);
 }
 
 static int
 iscsi_ioctl_session_modify(struct iscsi_softc *sc,
     struct iscsi_session_modify *ism)
 {
 	struct iscsi_session *is;
 	const struct iscsi_session *is2;
 
 	iscsi_sanitize_session_conf(&ism->ism_conf);
 	if (iscsi_valid_session_conf(&ism->ism_conf) == false)
 		return (EINVAL);
 
 	sx_xlock(&sc->sc_lock);
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		ISCSI_SESSION_LOCK(is);
 		if (is->is_id == ism->ism_session_id) {
 			/* Note that the session remains locked. */
 			break;
 		}
 		ISCSI_SESSION_UNLOCK(is);
 	}
 	if (is == NULL) {
 		sx_xunlock(&sc->sc_lock);
 		return (ESRCH);
 	}
 
 	/*
 	 * Prevent duplicates.
 	 */
 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
 		if (is == is2)
 			continue;
 
 		if (!!ism->ism_conf.isc_discovery !=
 		    !!is2->is_conf.isc_discovery)
 			continue;
 
 		if (strcmp(ism->ism_conf.isc_target_addr,
 		    is2->is_conf.isc_target_addr) != 0)
 			continue;
 
 		if (ism->ism_conf.isc_discovery == 0 &&
 		    strcmp(ism->ism_conf.isc_target,
 		    is2->is_conf.isc_target) != 0)
 			continue;
 
 		ISCSI_SESSION_UNLOCK(is);
 		sx_xunlock(&sc->sc_lock);
 		return (EBUSY);
 	}
 
 	sx_xunlock(&sc->sc_lock);
 
 	memcpy(&is->is_conf, &ism->ism_conf, sizeof(is->is_conf));
 	ISCSI_SESSION_UNLOCK(is);
 
 	iscsi_session_reconnect(is);
 
 	return (0);
 }
 
 static int
 iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
     struct thread *td)
 {
 	struct iscsi_softc *sc;
 
 	sc = dev->si_drv1;
 
 	switch (cmd) {
 	case ISCSIDWAIT:
 		return (iscsi_ioctl_daemon_wait(sc,
 		    (struct iscsi_daemon_request *)arg));
 	case ISCSIDHANDOFF:
 		return (iscsi_ioctl_daemon_handoff(sc,
 		    (struct iscsi_daemon_handoff *)arg));
 	case ISCSIDFAIL:
 		return (iscsi_ioctl_daemon_fail(sc,
 		    (struct iscsi_daemon_fail *)arg));
 #ifdef ICL_KERNEL_PROXY
 	case ISCSIDCONNECT:
 		return (iscsi_ioctl_daemon_connect(sc,
 		    (struct iscsi_daemon_connect *)arg));
 	case ISCSIDSEND:
 		return (iscsi_ioctl_daemon_send(sc,
 		    (struct iscsi_daemon_send *)arg));
 	case ISCSIDRECEIVE:
 		return (iscsi_ioctl_daemon_receive(sc,
 		    (struct iscsi_daemon_receive *)arg));
 #endif /* ICL_KERNEL_PROXY */
 	case ISCSISADD:
 		return (iscsi_ioctl_session_add(sc,
 		    (struct iscsi_session_add *)arg));
 	case ISCSISREMOVE:
 		return (iscsi_ioctl_session_remove(sc,
 		    (struct iscsi_session_remove *)arg));
 	case ISCSISLIST:
 		return (iscsi_ioctl_session_list(sc,
 		    (struct iscsi_session_list *)arg));
 	case ISCSISMODIFY:
 		return (iscsi_ioctl_session_modify(sc,
 		    (struct iscsi_session_modify *)arg));
 	default:
 		return (EINVAL);
 	}
 }
 
 static struct iscsi_outstanding *
 iscsi_outstanding_find(struct iscsi_session *is, uint32_t initiator_task_tag)
 {
 	struct iscsi_outstanding *io;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
 		if (io->io_initiator_task_tag == initiator_task_tag)
 			return (io);
 	}
 	return (NULL);
 }
 
 static struct iscsi_outstanding *
 iscsi_outstanding_find_ccb(struct iscsi_session *is, union ccb *ccb)
 {
 	struct iscsi_outstanding *io;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
 		if (io->io_ccb == ccb)
 			return (io);
 	}
 	return (NULL);
 }
 
 static struct iscsi_outstanding *
 iscsi_outstanding_add(struct iscsi_session *is, struct icl_pdu *request,
     union ccb *ccb, uint32_t *initiator_task_tagp)
 {
 	struct iscsi_outstanding *io;
 	int error;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	io = uma_zalloc(iscsi_outstanding_zone, M_NOWAIT | M_ZERO);
 	if (io == NULL) {
 		ISCSI_SESSION_WARN(is, "failed to allocate %zd bytes",
 		    sizeof(*io));
 		return (NULL);
 	}
 
 	error = icl_conn_task_setup(is->is_conn, request, &ccb->csio,
 	    initiator_task_tagp, &io->io_icl_prv);
 	if (error != 0) {
 		ISCSI_SESSION_WARN(is,
 		    "icl_conn_task_setup() failed with error %d", error);
 		uma_zfree(iscsi_outstanding_zone, io);
 		return (NULL);
 	}
 
 	KASSERT(iscsi_outstanding_find(is, *initiator_task_tagp) == NULL,
 	    ("initiator_task_tag 0x%x already added", *initiator_task_tagp));
 
 	io->io_initiator_task_tag = *initiator_task_tagp;
 	io->io_ccb = ccb;
 	TAILQ_INSERT_TAIL(&is->is_outstanding, io, io_next);
 	return (io);
 }
 
 static void
 iscsi_outstanding_remove(struct iscsi_session *is, struct iscsi_outstanding *io)
 {
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	icl_conn_task_done(is->is_conn, io->io_icl_prv);
 	TAILQ_REMOVE(&is->is_outstanding, io, io_next);
 	uma_zfree(iscsi_outstanding_zone, io);
 }
 
 static void
 iscsi_action_abort(struct iscsi_session *is, union ccb *ccb)
 {
 	struct icl_pdu *request;
 	struct iscsi_bhs_task_management_request *bhstmr;
 	struct ccb_abort *cab = &ccb->cab;
 	struct iscsi_outstanding *io, *aio;
 	uint32_t initiator_task_tag;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 #if 0
 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
 #else
 	if (is->is_login_phase) {
 		ccb->ccb_h.status = CAM_REQ_ABORTED;
 		xpt_done(ccb);
 		return;
 	}
 #endif
 
 	aio = iscsi_outstanding_find_ccb(is, cab->abort_ccb);
 	if (aio == NULL) {
 		ccb->ccb_h.status = CAM_REQ_CMP;
 		xpt_done(ccb);
 		return;
 	}
 
 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
 	if (request == NULL) {
 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
 		xpt_done(ccb);
 		return;
 	}
 
 	initiator_task_tag = is->is_initiator_task_tag++;
 	if (initiator_task_tag == 0xffffffff)
 		initiator_task_tag = is->is_initiator_task_tag++;
 
 	io = iscsi_outstanding_add(is, request, NULL, &initiator_task_tag);
 	if (io == NULL) {
 		icl_pdu_free(request);
 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
 		xpt_done(ccb);
 		return;
 	}
 	io->io_referenced_task_tag = aio->io_initiator_task_tag;
 
 	bhstmr = (struct iscsi_bhs_task_management_request *)request->ip_bhs;
 	bhstmr->bhstmr_opcode = ISCSI_BHS_OPCODE_TASK_REQUEST;
 	bhstmr->bhstmr_function = 0x80 | BHSTMR_FUNCTION_ABORT_TASK;
 	bhstmr->bhstmr_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
 	bhstmr->bhstmr_initiator_task_tag = initiator_task_tag;
 	bhstmr->bhstmr_referenced_task_tag = aio->io_initiator_task_tag;
 
 	iscsi_pdu_queue_locked(request);
 }
 
 static void
 iscsi_action_scsiio(struct iscsi_session *is, union ccb *ccb)
 {
 	struct icl_pdu *request;
 	struct iscsi_bhs_scsi_command *bhssc;
 	struct ccb_scsiio *csio;
 	struct iscsi_outstanding *io;
 	size_t len;
 	uint32_t initiator_task_tag;
 	int error;
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 #if 0
 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
 #else
 	if (is->is_login_phase) {
 		ISCSI_SESSION_DEBUG(is, "called during login phase");
 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 			xpt_freeze_devq(ccb->ccb_h.path, 1);
 			ISCSI_SESSION_DEBUG(is, "freezing devq");
 		}
 		ccb->ccb_h.status = CAM_REQ_ABORTED | CAM_DEV_QFRZN;
 		xpt_done(ccb);
 		return;
 	}
 #endif
 
 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
 	if (request == NULL) {
 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 			xpt_freeze_devq(ccb->ccb_h.path, 1);
 			ISCSI_SESSION_DEBUG(is, "freezing devq");
 		}
 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
 		xpt_done(ccb);
 		return;
 	}
 
 	initiator_task_tag = is->is_initiator_task_tag++;
 	if (initiator_task_tag == 0xffffffff)
 		initiator_task_tag = is->is_initiator_task_tag++;
 
 	io = iscsi_outstanding_add(is, request, ccb, &initiator_task_tag);
 	if (io == NULL) {
 		icl_pdu_free(request);
 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 			xpt_freeze_devq(ccb->ccb_h.path, 1);
 			ISCSI_SESSION_DEBUG(is, "freezing devq");
 		}
 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
 		xpt_done(ccb);
 		return;
 	}
 
 	csio = &ccb->csio;
 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
 	bhssc->bhssc_opcode = ISCSI_BHS_OPCODE_SCSI_COMMAND;
 	bhssc->bhssc_flags |= BHSSC_FLAGS_F;
 	switch (csio->ccb_h.flags & CAM_DIR_MASK) {
 	case CAM_DIR_IN:
 		bhssc->bhssc_flags |= BHSSC_FLAGS_R;
 		break;
 	case CAM_DIR_OUT:
 		bhssc->bhssc_flags |= BHSSC_FLAGS_W;
 		break;
 	}
 
 	if ((ccb->ccb_h.flags & CAM_TAG_ACTION_VALID) != 0) {
 		switch (csio->tag_action) {
 		case MSG_HEAD_OF_Q_TAG:
 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_HOQ;
 			break;
 		case MSG_ORDERED_Q_TAG:
 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ORDERED;
 			break;
 		case MSG_ACA_TASK:
 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ACA;
 			break;
 		case MSG_SIMPLE_Q_TAG:
 		default:
 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_SIMPLE;
 			break;
 		}
 	} else
 		bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_UNTAGGED;
 
 	if (is->is_protocol_level >= 2) {
 		bhssc->bhssc_pri = (csio->priority << BHSSC_PRI_SHIFT) &
 		    BHSSC_PRI_MASK;
 	}
 
 	bhssc->bhssc_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
 	bhssc->bhssc_initiator_task_tag = initiator_task_tag;
 	bhssc->bhssc_expected_data_transfer_length = htonl(csio->dxfer_len);
 	KASSERT(csio->cdb_len <= sizeof(bhssc->bhssc_cdb),
 	    ("unsupported CDB size %zd", (size_t)csio->cdb_len));
 
 	if (csio->ccb_h.flags & CAM_CDB_POINTER)
 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_ptr, csio->cdb_len);
 	else
 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_bytes, csio->cdb_len);
 
 	if (is->is_immediate_data &&
 	    (csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT) {
 		len = csio->dxfer_len;
 		//ISCSI_SESSION_DEBUG(is, "adding %zd of immediate data", len);
 		if (len > is->is_first_burst_length) {
 			ISCSI_SESSION_DEBUG(is, "len %zd -> %d", len, is->is_first_burst_length);
 			len = is->is_first_burst_length;
 		}
 		if (len > is->is_conn->ic_max_send_data_segment_length) {
 			ISCSI_SESSION_DEBUG(is, "len %zd -> %d", len,
 			    is->is_conn->ic_max_send_data_segment_length);
 			len = is->is_conn->ic_max_send_data_segment_length;
 		}
 
 		error = icl_pdu_append_data(request, csio->data_ptr, len, M_NOWAIT);
 		if (error != 0) {
 			iscsi_outstanding_remove(is, io);
 			icl_pdu_free(request);
 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
 				xpt_freeze_devq(ccb->ccb_h.path, 1);
 				ISCSI_SESSION_DEBUG(is, "freezing devq");
 			}
 			ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
 			xpt_done(ccb);
 			return;
 		}
 	}
 	iscsi_pdu_queue_locked(request);
 }
 
 static void
 iscsi_action(struct cam_sim *sim, union ccb *ccb)
 {
 	struct iscsi_session *is;
 
 	is = cam_sim_softc(sim);
 
 	ISCSI_SESSION_LOCK_ASSERT(is);
 
 	if (is->is_terminating ||
 	    (is->is_connected == false && fail_on_disconnection)) {
 		ccb->ccb_h.status = CAM_DEV_NOT_THERE;
 		xpt_done(ccb);
 		return;
 	}
 
 	/*
 	 * Make sure CAM doesn't sneak in a CCB just after freezing the queue.
 	 */
 	if (is->is_simq_frozen == true) {
 		ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
 		ccb->ccb_h.status |= CAM_REQUEUE_REQ;
 		/* Don't freeze the devq - the SIM queue is already frozen. */
 		xpt_done(ccb);
 		return;
 	}
 
 	switch (ccb->ccb_h.func_code) {
 	case XPT_PATH_INQ:
 	{
 		struct ccb_pathinq *cpi = &ccb->cpi;
 
 		cpi->version_num = 1;
 		cpi->hba_inquiry = PI_TAG_ABLE;
 		cpi->target_sprt = 0;
 		cpi->hba_misc = PIM_EXTLUNS;
 		/*
 		 * XXX: It shouldn't ever be NULL; this could be turned
 		 *      into a KASSERT eventually.
 		 */
 		if (is->is_conn == NULL)
 			ISCSI_WARN("NULL conn");
 		else if (is->is_conn->ic_unmapped)
 			cpi->hba_misc |= PIM_UNMAPPED;
 		cpi->hba_eng_cnt = 0;
 		cpi->max_target = 0;
 		/*
 		 * Note that the variable below is only relevant for targets
 		 * that don't claim compliance with anything above SPC2, which
 		 * means they don't support REPORT_LUNS.
 		 */
 		cpi->max_lun = 255;
 		cpi->initiator_id = ~0;
 		strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
 		strlcpy(cpi->hba_vid, "iSCSI", HBA_IDLEN);
 		strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
 		cpi->unit_number = cam_sim_unit(sim);
 		cpi->bus_id = cam_sim_bus(sim);
 		cpi->base_transfer_speed = 150000; /* XXX */
 		cpi->transport = XPORT_ISCSI;
 		cpi->transport_version = 0;
 		cpi->protocol = PROTO_SCSI;
 		cpi->protocol_version = SCSI_REV_SPC3;
 		cpi->maxio = maxphys;
 		cpi->ccb_h.status = CAM_REQ_CMP;
 		break;
 	}
 	case XPT_GET_TRAN_SETTINGS:
 	{
 		struct ccb_trans_settings	*cts;
 		struct ccb_trans_settings_scsi	*scsi;
 
 		cts = &ccb->cts;
 		scsi = &cts->proto_specific.scsi;
 
 		cts->protocol = PROTO_SCSI;
 		cts->protocol_version = SCSI_REV_SPC3;
 		cts->transport = XPORT_ISCSI;
 		cts->transport_version = 0;
 		scsi->valid = CTS_SCSI_VALID_TQ;
 		scsi->flags = CTS_SCSI_FLAGS_TAG_ENB;
 		cts->ccb_h.status = CAM_REQ_CMP;
 		break;
 	}
 	case XPT_CALC_GEOMETRY:
 		cam_calc_geometry(&ccb->ccg, /*extended*/1);
 		ccb->ccb_h.status = CAM_REQ_CMP;
 		break;
 #if 0
 	/*
 	 * XXX: What's the point?
 	 */
 	case XPT_RESET_BUS:
 	case XPT_TERM_IO:
 		ISCSI_SESSION_DEBUG(is, "faking success for reset, abort, or term_io");
 		ccb->ccb_h.status = CAM_REQ_CMP;
 		break;
 #endif
 	case XPT_ABORT:
 		iscsi_action_abort(is, ccb);
 		return;
 	case XPT_SCSI_IO:
 		iscsi_action_scsiio(is, ccb);
 		return;
 	default:
 #if 0
 		ISCSI_SESSION_DEBUG(is, "got unsupported code 0x%x", ccb->ccb_h.func_code);
 #endif
 		ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
 		break;
 	}
 	xpt_done(ccb);
 }
 
 static void
 iscsi_terminate_sessions(struct iscsi_softc *sc)
 {
 	struct iscsi_session *is;
 
 	sx_slock(&sc->sc_lock);
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next)
 		iscsi_session_terminate(is);
 	while(!TAILQ_EMPTY(&sc->sc_sessions)) {
 		ISCSI_DEBUG("waiting for sessions to terminate");
 		cv_wait(&sc->sc_cv, &sc->sc_lock);
 	}
 	ISCSI_DEBUG("all sessions terminated");
 	sx_sunlock(&sc->sc_lock);
 }
 
 static void
 iscsi_shutdown_pre(struct iscsi_softc *sc)
 {
 	struct iscsi_session *is;
 
 	if (!fail_on_shutdown)
 		return;
 
 	/*
 	 * If we have any sessions waiting for reconnection, request
 	 * maintenance thread to fail them immediately instead of waiting
 	 * for reconnect timeout.
 	 *
 	 * This prevents LUNs with mounted filesystems that are supported
 	 * by disconnected iSCSI sessions from hanging, however it will
 	 * fail all queued BIOs.
 	 */
 	ISCSI_DEBUG("forcing failing all disconnected sessions due to shutdown");
 
 	fail_on_disconnection = 1;
 
 	sx_slock(&sc->sc_lock);
 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 		ISCSI_SESSION_LOCK(is);
 		if (!is->is_connected) {
 			ISCSI_SESSION_DEBUG(is, "force failing disconnected session early");
 			iscsi_session_reconnect(is);
 		}
 		ISCSI_SESSION_UNLOCK(is);
 	}
 	sx_sunlock(&sc->sc_lock);
 }
 
 static void
 iscsi_shutdown_post(struct iscsi_softc *sc)
 {
 
 	if (!KERNEL_PANICKED()) {
 		ISCSI_DEBUG("removing all sessions due to shutdown");
 		iscsi_terminate_sessions(sc);
 	}
 }
 
 static int
 iscsi_load(void)
 {
 	int error;
 
 	sc = malloc(sizeof(*sc), M_ISCSI, M_ZERO | M_WAITOK);
 	sx_init(&sc->sc_lock, "iscsi");
 	TAILQ_INIT(&sc->sc_sessions);
 	cv_init(&sc->sc_cv, "iscsi_cv");
 
 	iscsi_outstanding_zone = uma_zcreate("iscsi_outstanding",
 	    sizeof(struct iscsi_outstanding), NULL, NULL, NULL, NULL,
 	    UMA_ALIGN_PTR, 0);
 
 	error = make_dev_p(MAKEDEV_CHECKNAME, &sc->sc_cdev, &iscsi_cdevsw,
 	    NULL, UID_ROOT, GID_WHEEL, 0600, "iscsi");
 	if (error != 0) {
 		ISCSI_WARN("failed to create device node, error %d", error);
 		return (error);
 	}
 	sc->sc_cdev->si_drv1 = sc;
 
 	sc->sc_shutdown_pre_eh = EVENTHANDLER_REGISTER(shutdown_pre_sync,
 	    iscsi_shutdown_pre, sc, SHUTDOWN_PRI_FIRST);
 	/*
 	 * shutdown_post_sync needs to run after filesystem shutdown and before
 	 * CAM shutdown - otherwise when rebooting with an iSCSI session that is
 	 * disconnected but has outstanding requests, dashutdown() will hang on
 	 * cam_periph_runccb().
 	 */
 	sc->sc_shutdown_post_eh = EVENTHANDLER_REGISTER(shutdown_post_sync,
 	    iscsi_shutdown_post, sc, SHUTDOWN_PRI_DEFAULT - 1);
 
 	return (0);
 }
 
 static int
 iscsi_unload(void)
 {
 
 	/* Awaken any threads asleep in iscsi_ioctl(). */
 	sx_xlock(&sc->sc_lock);
 	sc->sc_unloading = true;
 	cv_signal(&sc->sc_cv);
 	sx_xunlock(&sc->sc_lock);
 
 	if (sc->sc_cdev != NULL) {
 		ISCSI_DEBUG("removing device node");
 		destroy_dev(sc->sc_cdev);
 		ISCSI_DEBUG("device node removed");
 	}
 
 	if (sc->sc_shutdown_pre_eh != NULL)
 		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, sc->sc_shutdown_pre_eh);
 	if (sc->sc_shutdown_post_eh != NULL)
 		EVENTHANDLER_DEREGISTER(shutdown_post_sync, sc->sc_shutdown_post_eh);
 
 	iscsi_terminate_sessions(sc);
 
 	uma_zdestroy(iscsi_outstanding_zone);
 	sx_destroy(&sc->sc_lock);
 	cv_destroy(&sc->sc_cv);
 	free(sc, M_ISCSI);
 	return (0);
 }
 
 static int
 iscsi_quiesce(void)
 {
 	sx_slock(&sc->sc_lock);
 	if (!TAILQ_EMPTY(&sc->sc_sessions)) {
 		sx_sunlock(&sc->sc_lock);
 		return (EBUSY);
 	}
 	sx_sunlock(&sc->sc_lock);
 	return (0);
 }
 
 static int
 iscsi_modevent(module_t mod, int what, void *arg)
 {
 	int error;
 
 	switch (what) {
 	case MOD_LOAD:
 		error = iscsi_load();
 		break;
 	case MOD_UNLOAD:
 		error = iscsi_unload();
 		break;
 	case MOD_QUIESCE:
 		error = iscsi_quiesce();
 		break;
 	default:
 		error = EINVAL;
 		break;
 	}
 	return (error);
 }
 
 moduledata_t iscsi_data = {
 	"iscsi",
 	iscsi_modevent,
 	0
 };
 
 DECLARE_MODULE(iscsi, iscsi_data, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
 MODULE_DEPEND(iscsi, cam, 1, 1, 1);
 MODULE_DEPEND(iscsi, icl, 1, 1, 1);