1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2000 by Cisco Systems, Inc.  All rights reserved.
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  *
26  * iSCSI Pseudo HBA Driver
27  */
28 
29 #include <sys/socket.h>		/* networking stuff */
30 #include <sys/t_kuser.h>	/* networking stuff */
31 #include <sys/tihdr.h>		/* networking stuff */
32 #include <sys/strsubr.h>	/* networking stuff */
33 #include <netinet/tcp.h>	/* TCP_NODELAY */
34 #include <sys/socketvar.h>	/* _ALLOC_SLEEP */
35 #include <sys/strsun.h>		/* DB_TYPE() */
36 #include <sys/scsi/generic/sense.h>
37 
38 #include "iscsi.h"		/* iscsi driver */
39 #include <sys/iscsi_protocol.h>	/* iscsi protocol */
40 
41 #define	ISCSI_INI_TASK_TTT	0xffffffff
42 #define	ISCSI_CONN_TIEMOUT_DETECT	20
43 
44 boolean_t iscsi_io_logging = B_FALSE;
45 
46 #define	ISCSI_CHECK_SCSI_READ(ICHK_CMD, ICHK_HDR, ICHK_LEN, ICHK_TYPE)	\
47 	if (idm_pattern_checking)  {					\
48 		struct scsi_pkt *pkt = (ICHK_CMD)->cmd_un.scsi.pkt;	\
49 		if (((ICHK_HDR)->response == 0) && 			\
50 		    ((ICHK_HDR)->cmd_status == 0) &&			\
51 		    ((pkt->pkt_cdbp[0] == SCMD_READ_G1) ||		\
52 		    (pkt->pkt_cdbp[0] == SCMD_READ_G4) || 		\
53 		    (pkt->pkt_cdbp[0] == SCMD_READ) || 			\
54 		    (pkt->pkt_cdbp[0] == SCMD_READ_G5))) {		\
55 			idm_buf_t *idb = (ICHK_CMD)->cmd_un.scsi.ibp_ibuf; \
56 			IDM_BUFPAT_CHECK(idb, ICHK_LEN, ICHK_TYPE); \
57 		}						\
58 	}
59 
60 /* generic io helpers */
61 static uint32_t n2h24(uchar_t *ptr);
62 static int iscsi_sna_lt(uint32_t n1, uint32_t n2);
63 void iscsi_update_flow_control(iscsi_sess_t *isp,
64     uint32_t max, uint32_t exp);
65 static iscsi_status_t iscsi_rx_process_scsi_itt_to_icmdp(iscsi_sess_t *isp,
66     idm_conn_t *ic, iscsi_scsi_rsp_hdr_t *ihp, iscsi_cmd_t **icmdp);
67 static iscsi_status_t iscsi_rx_process_itt_to_icmdp(iscsi_sess_t *isp,
68     iscsi_hdr_t *ihp, iscsi_cmd_t **icmdp);
69 static void iscsi_process_rsp_status(iscsi_sess_t *isp, iscsi_conn_t *icp,
70     idm_status_t status);
71 static void iscsi_drop_conn_cleanup(iscsi_conn_t *icp);
72 static boolean_t iscsi_nop_timeout_checks(iscsi_cmd_t *icmdp);
73 /* callbacks from idm */
74 static idm_pdu_cb_t iscsi_tx_done;
75 
76 /* receivers */
77 static idm_status_t iscsi_rx_process_nop(idm_conn_t *ic, idm_pdu_t *pdu);
78 static idm_status_t iscsi_rx_process_data_rsp(idm_conn_t *ic,
79     idm_pdu_t *pdu);
80 static idm_status_t iscsi_rx_process_cmd_rsp(idm_conn_t *ic, idm_pdu_t *pdu);
81 static idm_status_t iscsi_rx_process_reject_rsp(idm_conn_t *ic,
82     idm_pdu_t *pdu);
83 
84 static idm_status_t iscsi_rx_process_rejected_tsk_mgt(idm_conn_t *ic,
85     iscsi_hdr_t *old_ihp);
86 static idm_status_t iscsi_rx_process_task_mgt_rsp(idm_conn_t *ic,
87     idm_pdu_t *pdu);
88 static idm_status_t iscsi_rx_process_logout_rsp(idm_conn_t *ic,
89     idm_pdu_t *pdu);
90 static idm_status_t iscsi_rx_process_async_rsp(idm_conn_t *ic,
91     idm_pdu_t *pdu);
92 static idm_status_t iscsi_rx_process_text_rsp(idm_conn_t *ic,
93     idm_pdu_t *pdu);
94 
95 /* senders */
96 static iscsi_status_t iscsi_tx_scsi(iscsi_sess_t *isp, iscsi_cmd_t *icmdp);
97 static iscsi_status_t iscsi_tx_nop(iscsi_sess_t *isp, iscsi_cmd_t *icmdp);
98 static iscsi_status_t iscsi_tx_abort(iscsi_sess_t *isp, iscsi_cmd_t *icmdp);
99 static iscsi_status_t iscsi_tx_reset(iscsi_sess_t *isp, iscsi_cmd_t *icmdp);
100 static iscsi_status_t iscsi_tx_logout(iscsi_sess_t *isp, iscsi_cmd_t *icmdp);
101 static iscsi_status_t iscsi_tx_text(iscsi_sess_t *isp, iscsi_cmd_t *icmdp);
102 
103 
104 /* helpers */
105 static void iscsi_logout_start(void *arg);
106 static void iscsi_handle_passthru_callback(struct scsi_pkt *pkt);
107 static void iscsi_handle_nop(iscsi_conn_t *icp, uint32_t itt, uint32_t ttt);
108 
109 static void iscsi_timeout_checks(iscsi_sess_t *isp);
110 static void iscsi_nop_checks(iscsi_sess_t *isp);
111 static boolean_t iscsi_decode_sense(uint8_t *sense_data);
112 static void iscsi_flush_cmd_after_reset(uint32_t cmd_sn, uint16_t lun_num,
113     iscsi_conn_t *icp);
114 
115 /*
116  * This file contains the main guts of the iSCSI protocol layer.
117  * It's broken into 5 sections; Basic helper functions, RX IO path,
118  * TX IO path, Completion (IC) IO path, and watchdog (WD) routines.
119  *
120  * The IO flow model is similiar to the below diagram.  The
121  * iscsi session, connection and command state machines are used
122  * to drive IO through this flow diagram.  Reference those files
123  * to get a detailed description of their respective state models
124  * prior to their xxx_state_machine_function().
125  *
126  * tran_start() -> CMD_E1     TX_THREAD                   RX_THREAD
127  *                   |            T                           T
128  *                   V            T                           T
129  *                PENDING_Q  --CMD_E2--> ACTIVE_Q -      --CMD_E3--+
130  *                                T                \ C        T    |
131  *                                T                 \M        T    |
132  *                                                   D        T    |
133  *                                       WD_THREAD TT|TT      T    |
134  *                                                  /E        T    |
135  *                                                 / 6        T    |
136  *                                     ABORTING_Q<-      --CMD_E3--+
137  *                                                            T    |
138  *                                T                           T    |
139  *                                T                                |
140  *               callback()  <--CMD_E#-- COMPLETION_Q <------------+
141  *                                T
142  *                                T
143  *                            IC_THREAD
144  *
145  * External and internal command are ran thru this same state
146  * machine.  All commands enter the state machine by receiving an
147  * ISCSI_CMD_EVENT_E1.  This event places the command into the
148  * PENDING_Q.  Next when resources are available the TX_THREAD
149  * issues a E2 event on the command.  This sends the command
150  * to the TCP stack and places the command on the ACTIVE_Q.  While
151  * on the PENDIING_Q and ACTIVE_Q, the command is monitored via the
152  * WD_THREAD to ensure the pkt_time has not elapsed.  If elapsed the
153  * command is issued an E6(timeout) event which moves either (if pending)
154  * completed the command or (if active) moves the command to the
155  * aborting queue and issues a SCSI TASK MANAGEMENT ABORT command
156  * to cancel the IO request.  If the original command is completed
157  * or the TASK MANAGEMENT command completes the command is moved
158  * to the COMPLETION_Q via a E3 event.  The IC_THREAD then processes
159  * the COMPLETION_Q and issues the scsi_pkt callback.  This
160  * callback can not be processed directly from the RX_THREAD
161  * because the callback might call back into the iscsi driver
162  * causing a deadlock condition.
163  *
164  * For more details on the complete CMD state machine reference
165  * the state machine diagram in iscsi_cmd.c.  The connection state
166  * machine is driven via IO events in this file.  Then session
167  * events are driven by the connection events.  For complete
168  * details on these state machines reference iscsi_sess.c and
169  * iscsi_conn.c
170  */
171 
172 
173 /*
174  * +--------------------------------------------------------------------+
175  * | io helper routines							|
176  * +--------------------------------------------------------------------+
177  */
178 
179 /*
180  * n2h24 - native to host 24 bit integer translation.
181  */
182 static uint32_t
183 n2h24(uchar_t *ptr)
184 {
185 	uint32_t idx;
186 	bcopy(ptr, &idx, 3);
187 	return (ntohl(idx) >> 8);
188 }
189 
190 /*
191  * iscsi_sna_lt - Serial Number Arithmetic, 32 bits, less than, RFC1982
192  */
193 static int
194 iscsi_sna_lt(uint32_t n1, uint32_t n2)
195 {
196 	return ((n1 != n2) &&
197 	    (((n1 < n2) && ((n2 - n1) < ISCSI_SNA32_CHECK)) ||
198 	    ((n1 > n2) && ((n1 - n2) > ISCSI_SNA32_CHECK))));
199 }
200 
201 /*
202  * iscsi_sna_lte - Serial Number Arithmetic, 32 bits, less than or equal,
203  * RFC1982
204  */
205 int
206 iscsi_sna_lte(uint32_t n1, uint32_t n2)
207 {
208 	return ((n1 == n2) ||
209 	    (((n1 < n2) && ((n2 - n1) < ISCSI_SNA32_CHECK)) ||
210 	    ((n1 > n2) && ((n1 - n2) > ISCSI_SNA32_CHECK))));
211 }
212 
213 /*
214  * iscsi_update_flow_control - Update expcmdsn and maxcmdsn iSCSI
215  * flow control information for a session
216  */
217 void
218 iscsi_update_flow_control(iscsi_sess_t *isp, uint32_t max, uint32_t exp)
219 {
220 	ASSERT(isp != NULL);
221 	ASSERT(mutex_owned(&isp->sess_cmdsn_mutex));
222 
223 	if (!iscsi_sna_lt(max, (exp - 1))) {
224 
225 		if (!iscsi_sna_lte(exp, isp->sess_expcmdsn)) {
226 			isp->sess_expcmdsn = exp;
227 		}
228 
229 		if (!iscsi_sna_lte(max, isp->sess_maxcmdsn)) {
230 			isp->sess_maxcmdsn = max;
231 			if (iscsi_sna_lte(isp->sess_cmdsn,
232 			    isp->sess_maxcmdsn)) {
233 				/*
234 				 * the window is open again - schedule
235 				 * to send any held tasks soon
236 				 */
237 				iscsi_sess_redrive_io(isp);
238 			}
239 		}
240 	}
241 }
242 
243 
244 /*
245  * +--------------------------------------------------------------------+
246  * | io receive and processing routines					|
247  * +--------------------------------------------------------------------+
248  */
249 
250 /*
251  * iscsi_rx_scsi_rsp - called from idm
252  * For each opcode type fan out the processing.
253  */
254 void
255 iscsi_rx_scsi_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
256 {
257 	iscsi_conn_t	*icp;
258 	iscsi_sess_t	*isp;
259 	iscsi_hdr_t	*ihp;
260 	idm_status_t	status;
261 
262 	ASSERT(ic != NULL);
263 	ASSERT(pdu != NULL);
264 	icp		= ic->ic_handle;
265 	ASSERT(icp != NULL);
266 	ihp		= (iscsi_hdr_t *)pdu->isp_hdr;
267 	ASSERT(ihp != NULL);
268 	isp		= icp->conn_sess;
269 	ASSERT(isp != NULL);
270 
271 	/* reset the session timer when we receive the response */
272 	isp->sess_rx_lbolt = icp->conn_rx_lbolt = ddi_get_lbolt();
273 
274 	/* fan out the hdr processing */
275 	switch (ihp->opcode & ISCSI_OPCODE_MASK) {
276 	case ISCSI_OP_SCSI_DATA_RSP:
277 		status = iscsi_rx_process_data_rsp(ic, pdu);
278 		break;
279 	case ISCSI_OP_SCSI_RSP:
280 		status = iscsi_rx_process_cmd_rsp(ic, pdu);
281 		idm_pdu_complete(pdu, status);
282 		break;
283 	default:
284 		cmn_err(CE_WARN, "iscsi connection(%u) protocol error - "
285 		    "received pdu with unsupported opcode 0x%02x",
286 		    icp->conn_oid, ihp->opcode);
287 		status = IDM_STATUS_PROTOCOL_ERROR;
288 	}
289 	iscsi_process_rsp_status(isp, icp, status);
290 }
291 
292 void
293 iscsi_task_cleanup(int opcode, iscsi_cmd_t *icmdp)
294 {
295 	struct buf 	*bp;
296 	idm_buf_t	*ibp, *obp;
297 	idm_task_t	*itp;
298 
299 	itp = icmdp->cmd_itp;
300 	ASSERT(itp != NULL);
301 	ASSERT((opcode == ISCSI_OP_SCSI_DATA_RSP) ||
302 	    (opcode == ISCSI_OP_SCSI_RSP));
303 
304 	bp = icmdp->cmd_un.scsi.bp;
305 	ibp = icmdp->cmd_un.scsi.ibp_ibuf;
306 	obp = icmdp->cmd_un.scsi.ibp_obuf;
307 	ISCSI_IO_LOG(CE_NOTE, "DEBUG: task_cleanup: itp: %p opcode: %d "
308 	    "icmdp: %p bp: %p ibp: %p", (void *)itp, opcode,
309 	    (void *)icmdp, (void *)bp, (void *)ibp);
310 	if (bp && bp->b_bcount) {
311 		if (ibp != NULL && bp->b_flags & B_READ) {
312 			idm_buf_unbind_in(itp, ibp);
313 			idm_buf_free(ibp);
314 			icmdp->cmd_un.scsi.ibp_ibuf = NULL;
315 		} else if (obp != NULL && !(bp->b_flags & B_READ)) {
316 			idm_buf_unbind_out(itp, obp);
317 			idm_buf_free(obp);
318 			icmdp->cmd_un.scsi.ibp_obuf = NULL;
319 		}
320 	}
321 
322 	idm_task_done(itp);
323 }
324 
325 idm_status_t
326 iscsi_rx_chk(iscsi_conn_t *icp, iscsi_sess_t *isp,
327     iscsi_scsi_rsp_hdr_t *irhp, iscsi_cmd_t **icmdp)
328 {
329 	iscsi_status_t rval;
330 
331 	mutex_enter(&isp->sess_cmdsn_mutex);
332 
333 	if (icp->conn_expstatsn == ntohl(irhp->statsn)) {
334 		icp->conn_expstatsn++;
335 	} else {
336 		cmn_err(CE_WARN, "iscsi connection(%u/%x) protocol error - "
337 		    "received status out of order itt:0x%x statsn:0x%x "
338 		    "expstatsn:0x%x", icp->conn_oid, irhp->opcode,
339 		    irhp->itt, ntohl(irhp->statsn), icp->conn_expstatsn);
340 		mutex_exit(&isp->sess_cmdsn_mutex);
341 		return (IDM_STATUS_PROTOCOL_ERROR);
342 	}
343 
344 	/* get icmdp so we can cleanup on error */
345 	if ((irhp->opcode == ISCSI_OP_SCSI_DATA_RSP) ||
346 	    (irhp->opcode == ISCSI_OP_SCSI_RSP)) {
347 		rval = iscsi_rx_process_scsi_itt_to_icmdp(isp, icp->conn_ic,
348 		    irhp, icmdp);
349 	} else {
350 		rval = iscsi_rx_process_itt_to_icmdp(isp,
351 		    (iscsi_hdr_t *)irhp, icmdp);
352 	}
353 
354 	if (!ISCSI_SUCCESS(rval)) {
355 		mutex_exit(&isp->sess_cmdsn_mutex);
356 		return (IDM_STATUS_PROTOCOL_ERROR);
357 	}
358 
359 	/* update expcmdsn and maxcmdsn */
360 	iscsi_update_flow_control(isp, ntohl(irhp->maxcmdsn),
361 	    ntohl(irhp->expcmdsn));
362 	mutex_exit(&isp->sess_cmdsn_mutex);
363 	return (IDM_STATUS_SUCCESS);
364 }
365 
366 static void
367 iscsi_cmd_rsp_chk(iscsi_cmd_t *icmdp, iscsi_scsi_rsp_hdr_t *issrhp)
368 {
369 	struct scsi_pkt *pkt;
370 	size_t data_transferred;
371 
372 	pkt = icmdp->cmd_un.scsi.pkt;
373 	pkt->pkt_resid = 0;
374 	data_transferred = icmdp->cmd_un.scsi.data_transferred;
375 	/* Check the residual count */
376 	if ((icmdp->cmd_un.scsi.bp) &&
377 	    (data_transferred != icmdp->cmd_un.scsi.bp->b_bcount)) {
378 		/*
379 		 * We didn't xfer the expected amount of data -
380 		 * the residual_count in the header is only
381 		 * valid if the underflow flag is set.
382 		 */
383 		if (issrhp->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
384 			pkt->pkt_resid = ntohl(issrhp->residual_count);
385 		} else {
386 			if (icmdp->cmd_un.scsi.bp->b_bcount >
387 			    data_transferred) {
388 				/*
389 				 * Some data fell on the floor
390 				 * somehow - probably a CRC error
391 				 */
392 				pkt->pkt_resid =
393 				    icmdp->cmd_un.scsi.bp->b_bcount -
394 				    data_transferred;
395 			}
396 		}
397 		ISCSI_IO_LOG(CE_NOTE,
398 		    "DEBUG: iscsi_rx_cmd_rsp_chk: itt: %u"
399 		    "data_trans != b_count data_transferred: %lu "
400 		    "b_count: %lu cmd_status: %d flags: %d resid: %lu",
401 		    issrhp->itt, data_transferred,
402 		    icmdp->cmd_un.scsi.bp->b_bcount,
403 		    issrhp->cmd_status & STATUS_MASK,
404 		    issrhp->flags, pkt->pkt_resid);
405 	}
406 	/* set flags that tell SCSA that the command is complete */
407 	if (icmdp->cmd_crc_error_seen == B_FALSE) {
408 		/* Set successful completion */
409 		pkt->pkt_reason = CMD_CMPLT;
410 		if (icmdp->cmd_un.scsi.bp) {
411 			pkt->pkt_state |= (STATE_XFERRED_DATA |
412 			    STATE_GOT_STATUS);
413 		} else {
414 			pkt->pkt_state |= STATE_GOT_STATUS;
415 		}
416 	} else {
417 		/*
418 		 * Some of the data was found to have an incorrect
419 		 * error at the protocol error.
420 		 */
421 		pkt->pkt_reason = CMD_PER_FAIL;
422 		pkt->pkt_statistics |= STAT_PERR;
423 		if (icmdp->cmd_un.scsi.bp) {
424 			pkt->pkt_resid =
425 			    icmdp->cmd_un.scsi.bp->b_bcount;
426 		} else {
427 			pkt->pkt_resid = 0;
428 		}
429 	}
430 }
431 
432 static boolean_t
433 iscsi_cmd_rsp_cmd_status(iscsi_cmd_t *icmdp, iscsi_scsi_rsp_hdr_t *issrhp,
434     uint8_t *data)
435 {
436 	int32_t			dlength		= 0;
437 	struct scsi_arq_status	*arqstat	= NULL;
438 	size_t			senselen	= 0;
439 	int32_t			statuslen	= 0;
440 	int32_t			senselen_to	= 0;
441 	struct scsi_pkt		*pkt;
442 	boolean_t		affect		= B_FALSE;
443 
444 	pkt = icmdp->cmd_un.scsi.pkt;
445 	dlength = n2h24(issrhp->dlength);
446 
447 	/*
448 	 * Process iSCSI Cmd Response Status
449 	 * RFC 3720 Sectionn 10.4.2.
450 	 */
451 	switch (issrhp->cmd_status & STATUS_MASK) {
452 	case STATUS_GOOD:
453 		/* pass SCSI status up stack */
454 		if (pkt->pkt_scbp) {
455 			pkt->pkt_scbp[0] = issrhp->cmd_status;
456 		}
457 		break;
458 	case STATUS_CHECK:
459 		/*
460 		 * Verify we received a sense buffer and
461 		 * that there is the correct amount of
462 		 * request sense space to copy it to.
463 		 */
464 		if ((dlength > 1) &&
465 		    (pkt->pkt_scbp != NULL) &&
466 		    (icmdp->cmd_un.scsi.statuslen >=
467 		    sizeof (struct scsi_arq_status))) {
468 			/*
469 			 * If a bad command status is received we
470 			 * need to reset the pkt_resid to zero.
471 			 * The target driver compares its value
472 			 * before checking other error flags.
473 			 * (ex. check conditions)
474 			 */
475 			pkt->pkt_resid = 0;
476 
477 			/* get sense length from first 2 bytes */
478 			senselen = ((data[0] << 8) | data[1]) &
479 			    (size_t)0xFFFF;
480 			ISCSI_IO_LOG(CE_NOTE,
481 			    "DEBUG: iscsi_rx_cmd_rsp_cmd_status status_check: "
482 			    "dlen: %d scbp: %p statuslen: %d arq: %d senselen:"
483 			    " %lu", dlength, (void *)pkt->pkt_scbp,
484 			    icmdp->cmd_un.scsi.statuslen,
485 			    (int)sizeof (struct scsi_arq_status),
486 			    senselen);
487 
488 			/* Sanity-check on the sense length */
489 			if ((senselen + 2) > dlength) {
490 				senselen = dlength - 2;
491 			}
492 
493 			/*
494 			 * If there was a Data Digest error then
495 			 * the sense data cannot be trusted.
496 			 */
497 			if (icmdp->cmd_crc_error_seen) {
498 				senselen = 0;
499 			}
500 
501 			/* automatic request sense */
502 			arqstat =
503 			    (struct scsi_arq_status *)pkt->pkt_scbp;
504 
505 			/* pass SCSI status up stack */
506 			*((uchar_t *)&arqstat->sts_status) =
507 			    issrhp->cmd_status;
508 
509 			/*
510 			 * Set the status for the automatic
511 			 * request sense command
512 			 */
513 			arqstat->sts_rqpkt_state = (STATE_GOT_BUS |
514 			    STATE_GOT_TARGET | STATE_SENT_CMD |
515 			    STATE_XFERRED_DATA | STATE_GOT_STATUS |
516 			    STATE_ARQ_DONE);
517 
518 			*((uchar_t *)&arqstat->sts_rqpkt_status) =
519 			    STATUS_GOOD;
520 
521 			arqstat->sts_rqpkt_reason = CMD_CMPLT;
522 			statuslen = icmdp->cmd_un.scsi.statuslen;
523 
524 			if (senselen == 0) {
525 				/* auto request sense failed */
526 				arqstat->sts_rqpkt_status.sts_chk = 1;
527 				arqstat->sts_rqpkt_resid = statuslen;
528 			} else if (senselen < statuslen) {
529 				/* auto request sense short */
530 				arqstat->sts_rqpkt_resid = statuslen - senselen;
531 			} else {
532 				/* auto request sense complete */
533 				arqstat->sts_rqpkt_resid = 0;
534 			}
535 			arqstat->sts_rqpkt_statistics = 0;
536 			pkt->pkt_state |= STATE_ARQ_DONE;
537 
538 			if (icmdp->cmd_misc_flags & ISCSI_CMD_MISCFLAG_XARQ) {
539 				pkt->pkt_state |= STATE_XARQ_DONE;
540 			}
541 
542 			senselen_to =  pkt->pkt_scblen -
543 			    sizeof (struct scsi_arq_status) +
544 			    sizeof (struct scsi_extended_sense);
545 
546 			/* copy auto request sense */
547 			dlength = min(senselen, senselen_to);
548 			if (dlength > 0) {
549 				bcopy(&data[2], (uchar_t *)&arqstat->
550 				    sts_sensedata, dlength);
551 
552 				affect = iscsi_decode_sense(
553 				    (uint8_t *)&arqstat->sts_sensedata);
554 			}
555 			break;
556 		}
557 		/* FALLTHRU */
558 	case STATUS_BUSY:
559 	case STATUS_RESERVATION_CONFLICT:
560 	case STATUS_QFULL:
561 	case STATUS_ACA_ACTIVE:
562 	default:
563 		/*
564 		 * If a bad command status is received we need to
565 		 * reset the pkt_resid to zero.  The target driver
566 		 * compares its value before checking other error
567 		 * flags. (ex. check conditions)
568 		 */
569 		ISCSI_IO_LOG(CE_NOTE,
570 		    "DEBUG: iscsi_rx_cmd_rsp_cmd_status: status: "
571 		    "%d cmd_status: %d dlen: %u scbp: %p statuslen: %d "
572 		    "arg_len: %d", issrhp->cmd_status & STATUS_MASK,
573 		    issrhp->cmd_status, dlength, (void *)pkt->pkt_scbp,
574 		    icmdp->cmd_un.scsi.statuslen,
575 		    (int)sizeof (struct scsi_arq_status));
576 		pkt->pkt_resid = 0;
577 		/* pass SCSI status up stack */
578 		if (pkt->pkt_scbp) {
579 			pkt->pkt_scbp[0] = issrhp->cmd_status;
580 		}
581 	}
582 
583 	return (affect);
584 }
585 
586 /*
587  * iscsi_rx_process_login_pdup - Process login response PDU.  This function
588  * copies the data into the connection context so that the login code can
589  * interpret it.
590  */
591 
592 idm_status_t
593 iscsi_rx_process_login_pdu(idm_conn_t *ic, idm_pdu_t *pdu)
594 {
595 	iscsi_conn_t 		*icp;
596 
597 	icp = ic->ic_handle;
598 
599 	/*
600 	 * Copy header and data into connection structure so iscsi_login()
601 	 * can process it.
602 	 */
603 	mutex_enter(&icp->conn_login_mutex);
604 	/*
605 	 * If conn_login_state != LOGIN_TX then we are not ready to handle
606 	 * this login response and we should just  drop it.
607 	 */
608 	if (icp->conn_login_state == LOGIN_TX) {
609 		icp->conn_login_datalen = pdu->isp_datalen;
610 		bcopy(pdu->isp_hdr, &icp->conn_login_resp_hdr,
611 		    sizeof (iscsi_hdr_t));
612 		/*
613 		 * Login code is sloppy with it's NULL handling so make sure
614 		 * we don't leave any stale data in there.
615 		 */
616 		bzero(icp->conn_login_data, icp->conn_login_max_data_length);
617 		bcopy(pdu->isp_data, icp->conn_login_data,
618 		    MIN(pdu->isp_datalen, icp->conn_login_max_data_length));
619 		iscsi_login_update_state_locked(icp, LOGIN_RX);
620 	}
621 	mutex_exit(&icp->conn_login_mutex);
622 
623 	return (IDM_STATUS_SUCCESS);
624 }
625 
626 /*
627  * iscsi_rx_process_cmd_rsp - Process received scsi command response.  This
628  * will contain sense data if the command was not successful.  This data needs
629  * to be copied into the scsi_pkt.  Otherwise we just complete the IO.
630  */
631 static idm_status_t
632 iscsi_rx_process_cmd_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
633 {
634 	iscsi_conn_t		*icp	= ic->ic_handle;
635 	iscsi_sess_t		*isp	= icp->conn_sess;
636 	iscsi_scsi_rsp_hdr_t	*issrhp	= (iscsi_scsi_rsp_hdr_t *)pdu->isp_hdr;
637 	uint8_t			*data	= pdu->isp_data;
638 	iscsi_cmd_t		*icmdp	= NULL;
639 	struct scsi_pkt		*pkt	= NULL;
640 	idm_status_t		rval;
641 	struct buf		*bp;
642 	boolean_t		flush	= B_FALSE;
643 	uint32_t		cmd_sn	= 0;
644 	uint16_t		lun_num = 0;
645 
646 	/* make sure we get status in order */
647 	mutex_enter(&icp->conn_queue_active.mutex);
648 
649 	if ((rval = iscsi_rx_chk(icp, isp, issrhp,
650 	    &icmdp)) != IDM_STATUS_SUCCESS) {
651 		if (icmdp != NULL) {
652 			iscsi_task_cleanup(issrhp->opcode, icmdp);
653 		}
654 		mutex_exit(&icp->conn_queue_active.mutex);
655 		return (rval);
656 	}
657 
658 	/*
659 	 * If we are in "idm aborting" state then we shouldn't continue
660 	 * to process this command.  By definition this command is no longer
661 	 * on the active queue so we shouldn't try to remove it either.
662 	 */
663 	mutex_enter(&icmdp->cmd_mutex);
664 	if (icmdp->cmd_state == ISCSI_CMD_STATE_IDM_ABORTING) {
665 		mutex_exit(&icmdp->cmd_mutex);
666 		mutex_exit(&icp->conn_queue_active.mutex);
667 		return (IDM_STATUS_SUCCESS);
668 	}
669 	mutex_exit(&icmdp->cmd_mutex);
670 
671 	/* Get the IDM buffer and bytes transferred */
672 	bp = icmdp->cmd_un.scsi.bp;
673 	if (ic->ic_conn_flags & IDM_CONN_USE_SCOREBOARD) {
674 		/* Transport tracks bytes transferred so use those counts */
675 		if (bp && (bp->b_flags & B_READ)) {
676 			icmdp->cmd_un.scsi.data_transferred +=
677 			    icmdp->cmd_itp->idt_rx_bytes;
678 		} else {
679 			icmdp->cmd_un.scsi.data_transferred +=
680 			    icmdp->cmd_itp->idt_tx_bytes;
681 		}
682 	} else {
683 		/*
684 		 * Some transports cannot track the bytes transferred on
685 		 * the initiator side (like iSER) so we have to use the
686 		 * status info.  If the response field indicates that
687 		 * the command actually completed then we will assume
688 		 * the data_transferred value represents the entire buffer
689 		 * unless the resid field says otherwise.  This is a bit
690 		 * unintuitive but it's really impossible to know what
691 		 * has been transferred without detailed consideration
692 		 * of the SCSI status and sense key and that is outside
693 		 * the scope of the transport.  Instead the target/class driver
694 		 * can consider these values along with the resid and figure
695 		 * it out.  The data_transferred concept is just belt and
696 		 * suspenders anyway -- RFC 3720 actually explicitly rejects
697 		 * scoreboarding ("Initiators SHOULD NOT keep track of the
698 		 * data transferred to or from the target (scoreboarding)")
699 		 * perhaps for this very reason.
700 		 */
701 		if (issrhp->response != 0) {
702 			icmdp->cmd_un.scsi.data_transferred = 0;
703 		} else {
704 			icmdp->cmd_un.scsi.data_transferred =
705 			    (bp == NULL) ? 0 : bp->b_bcount;
706 			if (issrhp->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
707 				icmdp->cmd_un.scsi.data_transferred -=
708 				    ntohl(issrhp->residual_count);
709 			}
710 		}
711 	}
712 
713 	ISCSI_CHECK_SCSI_READ(icmdp, issrhp,
714 	    icmdp->cmd_un.scsi.data_transferred,
715 	    BP_CHECK_THOROUGH);
716 
717 	ISCSI_IO_LOG(CE_NOTE, "DEBUG: rx_process_cmd_rsp: ic: %p pdu: %p itt:"
718 	    " %x expcmdsn: %x sess_cmd: %x sess_expcmdsn: %x data_transfered:"
719 	    " %lu ibp: %p obp: %p", (void *)ic, (void *)pdu, issrhp->itt,
720 	    issrhp->expcmdsn, isp->sess_cmdsn, isp->sess_expcmdsn,
721 	    icmdp->cmd_un.scsi.data_transferred,
722 	    (void *)icmdp->cmd_un.scsi.ibp_ibuf,
723 	    (void *)icmdp->cmd_un.scsi.ibp_obuf);
724 
725 	iscsi_task_cleanup(issrhp->opcode, icmdp);
726 
727 	if (issrhp->response) {
728 		/* The target failed the command. */
729 		ISCSI_IO_LOG(CE_NOTE, "DEBUG: rx_process_cmd_rsp: ic: %p pdu:"
730 		    " %p response: %d bcount: %lu", (void *)ic, (void *)pdu,
731 		    issrhp->response, icmdp->cmd_un.scsi.bp->b_bcount);
732 		pkt = icmdp->cmd_un.scsi.pkt;
733 		pkt->pkt_reason = CMD_TRAN_ERR;
734 		if (icmdp->cmd_un.scsi.bp) {
735 			pkt->pkt_resid = icmdp->cmd_un.scsi.bp->b_bcount;
736 		} else {
737 			pkt->pkt_resid = 0;
738 		}
739 	} else {
740 		/* success */
741 		iscsi_cmd_rsp_chk(icmdp, issrhp);
742 		flush = iscsi_cmd_rsp_cmd_status(icmdp, issrhp, data);
743 		if (flush == B_TRUE) {
744 			cmd_sn = icmdp->cmd_sn;
745 			ASSERT(icmdp->cmd_lun != NULL);
746 			lun_num = icmdp->cmd_lun->lun_num;
747 		}
748 	}
749 
750 	iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E3, isp);
751 	if (flush == B_TRUE) {
752 		iscsi_flush_cmd_after_reset(cmd_sn, lun_num, icp);
753 	}
754 	mutex_exit(&icp->conn_queue_active.mutex);
755 	return (IDM_STATUS_SUCCESS);
756 }
757 
758 static void
759 iscsi_data_rsp_pkt(iscsi_cmd_t *icmdp, iscsi_data_rsp_hdr_t *idrhp)
760 {
761 	struct buf		*bp	= NULL;
762 	size_t			data_transferred;
763 	struct scsi_pkt		*pkt;
764 
765 	bp = icmdp->cmd_un.scsi.bp;
766 	pkt = icmdp->cmd_un.scsi.pkt;
767 	data_transferred = icmdp->cmd_un.scsi.data_transferred;
768 	/*
769 	 * The command* must be completed now, since we won't get a command
770 	 * response PDU. The cmd_status and residual_count are
771 	 * not meaningful unless status_present is set.
772 	 */
773 	pkt->pkt_resid = 0;
774 	/* Check the residual count */
775 	if (bp && (data_transferred != bp->b_bcount)) {
776 		/*
777 		 * We didn't xfer the expected amount of data -
778 		 * the residual_count in the header is only valid
779 		 * if the underflow flag is set.
780 		 */
781 		if (idrhp->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
782 			pkt->pkt_resid = ntohl(idrhp->residual_count);
783 			ISCSI_IO_LOG(CE_NOTE, "DEBUG: iscsi_data_rsp_pkt: "
784 			    "underflow: itt: %d "
785 			    "transferred: %lu count: %lu", idrhp->itt,
786 			    data_transferred, bp->b_bcount);
787 		} else {
788 			if (bp->b_bcount > data_transferred) {
789 				/* Some data fell on the floor somehw */
790 				ISCSI_IO_LOG(CE_NOTE, "DEBUG: "
791 				    "iscsi_data_rsp_pkt: data fell: itt: %d "
792 				    "transferred: %lu count: %lu", idrhp->itt,
793 				    data_transferred, bp->b_bcount);
794 				pkt->pkt_resid =
795 				    bp->b_bcount - data_transferred;
796 			}
797 		}
798 	}
799 
800 	pkt->pkt_reason = CMD_CMPLT;
801 	pkt->pkt_state |= (STATE_XFERRED_DATA | STATE_GOT_STATUS);
802 
803 	if (((idrhp->cmd_status & STATUS_MASK) != STATUS_GOOD) &&
804 	    (icmdp->cmd_un.scsi.statuslen >=
805 	    sizeof (struct scsi_arq_status)) && pkt->pkt_scbp) {
806 
807 		/*
808 		 * Not supposed to get exception status here!
809 		 * We have no request sense data so just do the
810 		 * best we can
811 		 */
812 		struct scsi_arq_status *arqstat =
813 		    (struct scsi_arq_status *)pkt->pkt_scbp;
814 
815 
816 		bzero(arqstat, sizeof (struct scsi_arq_status));
817 
818 		*((uchar_t *)&arqstat->sts_status) =
819 		    idrhp->cmd_status;
820 
821 		arqstat->sts_rqpkt_resid =
822 		    sizeof (struct scsi_extended_sense);
823 		ISCSI_IO_LOG(CE_NOTE, "DEBUG: iscsi_data_rsp_pkt: "
824 		    "exception status: itt: %d resid: %d",
825 		    idrhp->itt, arqstat->sts_rqpkt_resid);
826 
827 	} else if (pkt->pkt_scbp) {
828 		/* just pass along the status we got */
829 		pkt->pkt_scbp[0] = idrhp->cmd_status;
830 	}
831 }
832 
833 /*
834  * iscsi_rx_process_data_rsp -
835  * This currently processes the final data sequence denoted by the data response
836  * PDU Status bit being set.  We will not receive the SCSI response.
837  * This bit denotes that the PDU is the successful completion of the
838  * command.
839  */
840 static idm_status_t
841 iscsi_rx_process_data_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
842 {
843 	iscsi_sess_t		*isp	= NULL;
844 	iscsi_data_rsp_hdr_t	*idrhp	= (iscsi_data_rsp_hdr_t *)pdu->isp_hdr;
845 	iscsi_cmd_t		*icmdp	= NULL;
846 	struct buf		*bp	= NULL;
847 	iscsi_conn_t		*icp	= ic->ic_handle;
848 	idm_buf_t		*ibp;
849 	idm_status_t		rval;
850 
851 
852 	/* should only call this when the data rsp contains final rsp */
853 	ASSERT(idrhp->flags & ISCSI_FLAG_DATA_STATUS);
854 	isp = icp->conn_sess;
855 
856 	mutex_enter(&icp->conn_queue_active.mutex);
857 	if ((rval = iscsi_rx_chk(icp, isp, (iscsi_scsi_rsp_hdr_t *)idrhp,
858 	    &icmdp)) != IDM_STATUS_SUCCESS) {
859 		if (icmdp != NULL) {
860 			iscsi_task_cleanup(idrhp->opcode, icmdp);
861 		}
862 		mutex_exit(&icp->conn_queue_active.mutex);
863 		return (rval);
864 	}
865 
866 	/*
867 	 * If we are in "idm aborting" state then we shouldn't continue
868 	 * to process this command.  By definition this command is no longer
869 	 * on the active queue so we shouldn't try to remove it either.
870 	 */
871 	mutex_enter(&icmdp->cmd_mutex);
872 	if (icmdp->cmd_state == ISCSI_CMD_STATE_IDM_ABORTING) {
873 		mutex_exit(&icmdp->cmd_mutex);
874 		mutex_exit(&icp->conn_queue_active.mutex);
875 		return (IDM_STATUS_SUCCESS);
876 	}
877 	mutex_exit(&icmdp->cmd_mutex);
878 
879 	/*
880 	 * Holding the pending/active queue locks across the
881 	 * iscsi_rx_data call later in this function may cause
882 	 * deadlock during fault injections.  Instead remove
883 	 * the cmd from the active queue and release the locks.
884 	 * Then before returning or completing the command
885 	 * return the cmd to the active queue and reacquire
886 	 * the locks.
887 	 */
888 	iscsi_dequeue_active_cmd(icp, icmdp);
889 
890 	mutex_exit(&icp->conn_queue_active.mutex);
891 
892 	/* shorthand some values */
893 	bp = icmdp->cmd_un.scsi.bp;
894 
895 	/*
896 	 * some poorly behaved targets have been observed
897 	 * sending data-in pdu's during a write operation
898 	 */
899 	if (bp != NULL) {
900 		if (!(bp->b_flags & B_READ)) {
901 			cmn_err(CE_WARN,
902 			    "iscsi connection(%u) protocol error - "
903 			    "received data response during write operation "
904 			    "itt:0x%x",
905 			    icp->conn_oid, idrhp->itt);
906 			mutex_enter(&icp->conn_queue_active.mutex);
907 			iscsi_enqueue_active_cmd(icp, icmdp);
908 			mutex_exit(&icp->conn_queue_active.mutex);
909 			return (IDM_STATUS_PROTOCOL_ERROR);
910 		}
911 	}
912 
913 	ibp = icmdp->cmd_un.scsi.ibp_ibuf;
914 	if (ibp == NULL) {
915 		/*
916 		 * After the check of bp above we *should* have a corresponding
917 		 * idm_buf_t (ibp).  It's possible that the original call
918 		 * to idm_buf_alloc failed due to a pending connection state
919 		 * transition in which case this value can be NULL.  It's
920 		 * highly unlikely that the connection would be shutting down
921 		 * *and* we manage to process a data response and get to this
922 		 * point in the code but just in case we should check for it.
923 		 * This isn't really a protocol error -- we are almost certainly
924 		 * closing the connection anyway so just return a generic error.
925 		 */
926 		mutex_enter(&icp->conn_queue_active.mutex);
927 		iscsi_enqueue_active_cmd(icp, icmdp);
928 		mutex_exit(&icp->conn_queue_active.mutex);
929 		return (IDM_STATUS_FAIL);
930 	}
931 
932 	if (ic->ic_conn_flags & IDM_CONN_USE_SCOREBOARD) {
933 		icmdp->cmd_un.scsi.data_transferred =
934 		    icmdp->cmd_itp->idt_rx_bytes;
935 	} else {
936 		icmdp->cmd_un.scsi.data_transferred = bp->b_bcount;
937 		if (idrhp->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
938 			icmdp->cmd_un.scsi.data_transferred -=
939 			    ntohl(idrhp->residual_count);
940 		}
941 	}
942 
943 	ISCSI_IO_LOG(CE_NOTE, "DEBUG: rx_process_data_rsp: icp: %p pdu: %p "
944 	    "itt: %d ibp: %p icmdp: %p xfer_len: %lu transferred: %lu dlen: %u",
945 	    (void *)icp, (void *)pdu, idrhp->itt, (void *)bp, (void *)icmdp,
946 	    (ibp == NULL) ? 0 : ibp->idb_xfer_len,
947 	    icmdp->cmd_un.scsi.data_transferred,
948 	    n2h24(idrhp->dlength));
949 
950 	iscsi_task_cleanup(idrhp->opcode, icmdp);
951 
952 	iscsi_data_rsp_pkt(icmdp, idrhp);
953 
954 	mutex_enter(&icp->conn_queue_active.mutex);
955 	iscsi_enqueue_active_cmd(icp, icmdp);
956 	iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E3, isp);
957 	mutex_exit(&icp->conn_queue_active.mutex);
958 
959 	return (IDM_STATUS_SUCCESS);
960 }
961 
962 /*
963  * iscsi_rx_process_nop - Process a received nop.  If nop is in response
964  * to a ping we sent update stats.  If initiated by the target we need
965  * to response back to the target with a nop.  Schedule the response.
966  */
967 /* ARGSUSED */
968 static idm_status_t
969 iscsi_rx_process_nop(idm_conn_t *ic, idm_pdu_t *pdu)
970 {
971 	iscsi_sess_t		*isp	= NULL;
972 	iscsi_nop_in_hdr_t	*inihp	= (iscsi_nop_in_hdr_t *)pdu->isp_hdr;
973 	iscsi_cmd_t		*icmdp	= NULL;
974 	iscsi_conn_t		*icp	= ic->ic_handle;
975 
976 	if (icp->conn_expstatsn != ntohl(inihp->statsn)) {
977 		cmn_err(CE_WARN, "iscsi connection(%u/%x) protocol error - "
978 		    "received status out of order itt:0x%x statsn:0x%x "
979 		    "expstatsn:0x%x", icp->conn_oid, inihp->opcode, inihp->itt,
980 		    ntohl(inihp->statsn), icp->conn_expstatsn);
981 		return (IDM_STATUS_PROTOCOL_ERROR);
982 	}
983 	isp = icp->conn_sess;
984 	ASSERT(isp != NULL);
985 	mutex_enter(&isp->sess_queue_pending.mutex);
986 	mutex_enter(&icp->conn_queue_active.mutex);
987 	mutex_enter(&isp->sess_cmdsn_mutex);
988 	if (inihp->itt != ISCSI_RSVD_TASK_TAG) {
989 		if (!ISCSI_SUCCESS(iscsi_rx_process_itt_to_icmdp(
990 		    isp, (iscsi_hdr_t *)inihp, &icmdp))) {
991 			cmn_err(CE_WARN, "iscsi connection(%u) protocol error "
992 			    "- can not find cmd for itt:0x%x",
993 			    icp->conn_oid, inihp->itt);
994 			mutex_exit(&isp->sess_cmdsn_mutex);
995 			mutex_exit(&icp->conn_queue_active.mutex);
996 			mutex_exit(&isp->sess_queue_pending.mutex);
997 			return (IDM_STATUS_PROTOCOL_ERROR);
998 		}
999 	}
1000 
1001 	/* update expcmdsn and maxcmdsn */
1002 	iscsi_update_flow_control(isp, ntohl(inihp->maxcmdsn),
1003 	    ntohl(inihp->expcmdsn));
1004 	mutex_exit(&isp->sess_cmdsn_mutex);
1005 
1006 	if ((inihp->itt != ISCSI_RSVD_TASK_TAG) &&
1007 	    (inihp->ttt == ISCSI_RSVD_TASK_TAG)) {
1008 		/* This is the only type of nop that incs. the expstatsn */
1009 		icp->conn_expstatsn++;
1010 
1011 		/*
1012 		 * This is a targets response to our nop
1013 		 */
1014 		iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E3, isp);
1015 	} else if (inihp->ttt != ISCSI_RSVD_TASK_TAG) {
1016 		/*
1017 		 * Target requested a nop.  Send one.
1018 		 */
1019 		iscsi_handle_nop(icp, ISCSI_RSVD_TASK_TAG, inihp->ttt);
1020 	} else {
1021 		/*
1022 		 * This is a target-initiated ping that doesn't expect
1023 		 * a response; nothing to do except update our flow control
1024 		 * (which we do in all cases above).
1025 		 */
1026 		/* EMPTY */
1027 	}
1028 	mutex_exit(&icp->conn_queue_active.mutex);
1029 	mutex_exit(&isp->sess_queue_pending.mutex);
1030 
1031 	return (IDM_STATUS_SUCCESS);
1032 }
1033 
1034 
1035 /*
1036  * iscsi_rx_process_reject_rsp - The server rejected a PDU
1037  */
1038 static idm_status_t
1039 iscsi_rx_process_reject_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
1040 {
1041 	iscsi_reject_rsp_hdr_t	*irrhp = (iscsi_reject_rsp_hdr_t *)pdu->isp_hdr;
1042 	iscsi_sess_t		*isp		= NULL;
1043 	uint32_t		dlength		= 0;
1044 	iscsi_hdr_t		*old_ihp	= NULL;
1045 	iscsi_conn_t		*icp		= ic->ic_handle;
1046 	uint8_t			*data 		= pdu->isp_data;
1047 	iscsi_hdr_t		*ihp		= (iscsi_hdr_t *)irrhp;
1048 	idm_status_t		status;
1049 	iscsi_cmd_t		*icmdp	= NULL;
1050 
1051 	ASSERT(data != NULL);
1052 	isp = icp->conn_sess;
1053 	ASSERT(isp != NULL);
1054 
1055 	mutex_enter(&icp->conn_queue_active.mutex);
1056 	if ((status = iscsi_rx_chk(icp, isp, (iscsi_scsi_rsp_hdr_t *)irrhp,
1057 	    &icmdp)) != IDM_STATUS_SUCCESS) {
1058 		mutex_exit(&icp->conn_queue_active.mutex);
1059 		return (status);
1060 	}
1061 
1062 	/* If we don't have the rejected header we can't do anything */
1063 	dlength = n2h24(irrhp->dlength);
1064 	if (dlength < sizeof (iscsi_hdr_t)) {
1065 		return (IDM_STATUS_PROTOCOL_ERROR);
1066 	}
1067 
1068 	/* map old ihp */
1069 	old_ihp = (iscsi_hdr_t *)data;
1070 
1071 	switch (irrhp->reason) {
1072 	/*
1073 	 * ISCSI_REJECT_IMM_CMD_REJECT - Immediate Command Reject
1074 	 * too many immediate commands (original cmd can be resent)
1075 	 */
1076 	case ISCSI_REJECT_IMM_CMD_REJECT:
1077 		/*
1078 		 * We have exceeded the server's capacity for outstanding
1079 		 * immediate commands.   This must be a task management
1080 		 * command so try to find it in the abortingqueue and
1081 		 * complete it.
1082 		 */
1083 		if (!(old_ihp->opcode & ISCSI_OP_IMMEDIATE)) {
1084 			/* Rejecting IMM but old old_hdr wasn't IMM */
1085 			return (IDM_STATUS_PROTOCOL_ERROR);
1086 		}
1087 
1088 		/*
1089 		 * We only send NOP and TASK_MGT as IMM.  All other
1090 		 * cases should be considered as a protocol error.
1091 		 */
1092 		switch (old_ihp->opcode & ISCSI_OPCODE_MASK) {
1093 		case ISCSI_OP_NOOP_OUT:
1094 			/*
1095 			 * A ping was rejected - treat this like
1096 			 * ping response.  The down side is we
1097 			 * didn't get an updated MaxCmdSn.
1098 			 */
1099 			break;
1100 		case ISCSI_OP_SCSI_TASK_MGT_MSG:
1101 			(void) iscsi_rx_process_rejected_tsk_mgt(ic, old_ihp);
1102 			break;
1103 		default:
1104 			cmn_err(CE_WARN, "iscsi connection(%u) protocol error "
1105 			    "- received a reject for a command(0x%02x) not "
1106 			    "sent as an immediate", icp->conn_oid,
1107 			    old_ihp->opcode);
1108 			status = IDM_STATUS_PROTOCOL_ERROR;
1109 			break;
1110 		}
1111 		break;
1112 
1113 	/*
1114 	 * For the rest of the reject cases just use the general
1115 	 * hammer of dis/reconnecting.  This will resolve all
1116 	 * noted issues although could be more graceful.
1117 	 */
1118 	case ISCSI_REJECT_DATA_DIGEST_ERROR:
1119 	case ISCSI_REJECT_CMD_BEFORE_LOGIN:
1120 	case ISCSI_REJECT_SNACK_REJECT:
1121 	case ISCSI_REJECT_PROTOCOL_ERROR:
1122 	case ISCSI_REJECT_CMD_NOT_SUPPORTED:
1123 	case ISCSI_REJECT_TASK_IN_PROGRESS:
1124 	case ISCSI_REJECT_INVALID_DATA_ACK:
1125 	case ISCSI_REJECT_INVALID_PDU_FIELD:
1126 	case ISCSI_REJECT_LONG_OPERATION_REJECT:
1127 	case ISCSI_REJECT_NEGOTIATION_RESET:
1128 	default:
1129 		cmn_err(CE_WARN, "iscsi connection(%u) closing connection - "
1130 		    "target requested itt:0x%x reason:0x%x",
1131 		    icp->conn_oid, ihp->itt, irrhp->reason);
1132 		status = IDM_STATUS_PROTOCOL_ERROR;
1133 		break;
1134 	}
1135 
1136 	return (IDM_STATUS_SUCCESS);
1137 }
1138 
1139 
1140 /*
1141  * iscsi_rx_process_rejected_tsk_mgt -
1142  */
1143 /* ARGSUSED */
1144 static idm_status_t
1145 iscsi_rx_process_rejected_tsk_mgt(idm_conn_t *ic, iscsi_hdr_t *old_ihp)
1146 {
1147 	iscsi_sess_t		*isp	= NULL;
1148 	iscsi_cmd_t		*icmdp	= NULL;
1149 	iscsi_conn_t		*icp 	= NULL;
1150 
1151 	isp = icp->conn_sess;
1152 	ASSERT(old_ihp != NULL);
1153 	ASSERT(isp != NULL);
1154 
1155 	mutex_enter(&icp->conn_queue_active.mutex);
1156 	mutex_enter(&isp->sess_cmdsn_mutex);
1157 	if (!ISCSI_SUCCESS(iscsi_rx_process_itt_to_icmdp(
1158 	    isp, old_ihp, &icmdp))) {
1159 		mutex_exit(&isp->sess_cmdsn_mutex);
1160 		mutex_exit(&icp->conn_queue_active.mutex);
1161 		return (IDM_STATUS_PROTOCOL_ERROR);
1162 	}
1163 	mutex_exit(&isp->sess_cmdsn_mutex);
1164 
1165 	switch (icmdp->cmd_type) {
1166 	case ISCSI_CMD_TYPE_ABORT:
1167 	case ISCSI_CMD_TYPE_RESET:
1168 		iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E4,
1169 		    icp->conn_sess);
1170 		break;
1171 	/* We don't send any other task mgr types */
1172 	default:
1173 		ASSERT(B_FALSE);
1174 		break;
1175 	}
1176 	mutex_exit(&icp->conn_queue_active.mutex);
1177 
1178 	return (IDM_STATUS_SUCCESS);
1179 }
1180 
1181 
1182 /*
1183  * iscsi_rx_process_task_mgt_rsp -
1184  */
1185 /* ARGSUSED */
1186 static idm_status_t
1187 iscsi_rx_process_task_mgt_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
1188 {
1189 	iscsi_sess_t			*isp		= NULL;
1190 	iscsi_scsi_task_mgt_rsp_hdr_t	*istmrhp	= NULL;
1191 	iscsi_cmd_t			*icmdp		= NULL;
1192 	iscsi_conn_t			*icp		= ic->ic_handle;
1193 	idm_status_t			status = IDM_STATUS_SUCCESS;
1194 
1195 	isp = icp->conn_sess;
1196 	istmrhp = (iscsi_scsi_task_mgt_rsp_hdr_t *)pdu->isp_hdr;
1197 
1198 	mutex_enter(&icp->conn_queue_active.mutex);
1199 	if ((status = iscsi_rx_chk(icp, isp, (iscsi_scsi_rsp_hdr_t *)istmrhp,
1200 	    &icmdp)) != IDM_STATUS_SUCCESS) {
1201 		mutex_exit(&icp->conn_queue_active.mutex);
1202 		return (status);
1203 	}
1204 
1205 	switch (icmdp->cmd_type) {
1206 	case ISCSI_CMD_TYPE_ABORT:
1207 	case ISCSI_CMD_TYPE_RESET:
1208 		switch (istmrhp->response) {
1209 		case SCSI_TCP_TM_RESP_COMPLETE:
1210 			/* success */
1211 			iscsi_cmd_state_machine(icmdp,
1212 			    ISCSI_CMD_EVENT_E3, isp);
1213 			break;
1214 		case SCSI_TCP_TM_RESP_NO_TASK:
1215 			/*
1216 			 * If the array no longer knows about
1217 			 * an ABORT RTT and we no longer have
1218 			 * a parent SCSI command it was just
1219 			 * completed, free this ABORT resource.
1220 			 * Otherwise FALLTHRU this will flag a
1221 			 * protocol problem.
1222 			 */
1223 			if ((icmdp->cmd_type == ISCSI_CMD_TYPE_ABORT) &&
1224 			    (icmdp->cmd_un.abort.icmdp == NULL)) {
1225 				iscsi_cmd_state_machine(icmdp,
1226 				    ISCSI_CMD_EVENT_E4, isp);
1227 				break;
1228 			}
1229 			/* FALLTHRU */
1230 		case SCSI_TCP_TM_RESP_REJECTED:
1231 			/*
1232 			 * If the target rejects our reset task,
1233 			 * we should record the response and complete
1234 			 * this command with the result.
1235 			 */
1236 			if (icmdp->cmd_type == ISCSI_CMD_TYPE_RESET) {
1237 				icmdp->cmd_un.reset.response =
1238 				    istmrhp->response;
1239 				iscsi_cmd_state_machine(icmdp,
1240 				    ISCSI_CMD_EVENT_E3, isp);
1241 				break;
1242 			}
1243 			/* FALLTHRU */
1244 		case SCSI_TCP_TM_RESP_NO_LUN:
1245 		case SCSI_TCP_TM_RESP_TASK_ALLEGIANT:
1246 		case SCSI_TCP_TM_RESP_NO_FAILOVER:
1247 		case SCSI_TCP_TM_RESP_IN_PRGRESS:
1248 		default:
1249 			/*
1250 			 * Something is out of sync.  Flush
1251 			 * active queues and resync the
1252 			 * the connection to try and recover
1253 			 * to a known state.
1254 			 */
1255 			status = IDM_STATUS_PROTOCOL_ERROR;
1256 		}
1257 		break;
1258 
1259 	default:
1260 		cmn_err(CE_WARN, "iscsi connection(%u) protocol error - "
1261 		    "received a task mgt response for a non-task mgt "
1262 		    "cmd itt:0x%x type:%d", icp->conn_oid, istmrhp->itt,
1263 		    icmdp->cmd_type);
1264 		status = IDM_STATUS_PROTOCOL_ERROR;
1265 		break;
1266 	}
1267 
1268 	mutex_exit(&icp->conn_queue_active.mutex);
1269 	return (status);
1270 }
1271 
1272 
1273 /*
1274  * iscsi_rx_process_logout_rsp -
1275  *
1276  */
1277 /* ARGSUSED */
1278 idm_status_t
1279 iscsi_rx_process_logout_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
1280 {
1281 	iscsi_conn_t		*icp	= ic->ic_handle;
1282 	iscsi_logout_rsp_hdr_t	*ilrhp	=
1283 	    (iscsi_logout_rsp_hdr_t *)pdu->isp_hdr;
1284 	iscsi_cmd_t		*icmdp	= NULL;
1285 	iscsi_sess_t		*isp;
1286 	idm_status_t		status = IDM_STATUS_SUCCESS;
1287 
1288 	isp = icp->conn_sess;
1289 
1290 	if (icp->conn_expstatsn != ntohl(ilrhp->statsn)) {
1291 		cmn_err(CE_WARN, "iscsi connection(%u/%x) protocol error - "
1292 		    "received status out of order itt:0x%x statsn:0x%x "
1293 		    "expstatsn:0x%x", icp->conn_oid, ilrhp->opcode, ilrhp->itt,
1294 		    ntohl(ilrhp->statsn), icp->conn_expstatsn);
1295 		return (IDM_STATUS_PROTOCOL_ERROR);
1296 	}
1297 
1298 	mutex_enter(&icp->conn_queue_active.mutex);
1299 	mutex_enter(&isp->sess_cmdsn_mutex);
1300 	if (ilrhp->itt != ISCSI_RSVD_TASK_TAG) {
1301 		if (!ISCSI_SUCCESS(iscsi_rx_process_itt_to_icmdp(
1302 		    isp, (iscsi_hdr_t *)ilrhp, &icmdp))) {
1303 			mutex_exit(&isp->sess_cmdsn_mutex);
1304 			mutex_exit(&icp->conn_queue_active.mutex);
1305 			return (IDM_STATUS_PROTOCOL_ERROR);
1306 		}
1307 	}
1308 
1309 	/* update expcmdsn and maxcmdsn */
1310 	iscsi_update_flow_control(isp, ntohl(ilrhp->maxcmdsn),
1311 	    ntohl(ilrhp->expcmdsn));
1312 	mutex_exit(&isp->sess_cmdsn_mutex);
1313 
1314 	ISCSI_IO_LOG(CE_NOTE,
1315 	    "DEBUG: iscsi_rx_process_logout_rsp: response: %d",
1316 	    ilrhp->response);
1317 	switch (ilrhp->response) {
1318 	case ISCSI_LOGOUT_CID_NOT_FOUND:
1319 		/*
1320 		 * If the target doesn't know about our connection
1321 		 * then we can consider our self disconnected.
1322 		 */
1323 		/* FALLTHRU */
1324 	case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
1325 		/*
1326 		 * We don't support ErrorRecovery levels above 0
1327 		 * currently so consider this success.
1328 		 */
1329 		/* FALLTHRU */
1330 	case ISCSI_LOGOUT_CLEANUP_FAILED:
1331 		/*
1332 		 * per spec. "cleanup failed for various reasons."
1333 		 * Although those various reasons are undefined.
1334 		 * Not sure what to do here.  So fake success,
1335 		 * which will disconnect the connection.
1336 		 */
1337 		/* FALLTHRU */
1338 	case ISCSI_LOGOUT_SUCCESS:
1339 		iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E3, isp);
1340 		mutex_exit(&icp->conn_queue_active.mutex);
1341 		iscsi_drop_conn_cleanup(icp);
1342 		break;
1343 	default:
1344 		mutex_exit(&icp->conn_queue_active.mutex);
1345 		status = IDM_STATUS_PROTOCOL_ERROR;
1346 		break;
1347 
1348 	}
1349 	return (status);
1350 }
1351 
1352 /*
1353  * iscsi_rx_process_async_rsp
1354  *
1355  */
1356 /* ARGSUSED */
1357 static idm_status_t
1358 iscsi_rx_process_async_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
1359 {
1360 	iscsi_conn_t		*icp	= ic->ic_handle;
1361 	iscsi_sess_t		*isp	= icp->conn_sess;
1362 	idm_status_t		rval	= IDM_STATUS_SUCCESS;
1363 	iscsi_task_t		*itp;
1364 	iscsi_async_evt_hdr_t	*iaehp	=
1365 	    (iscsi_async_evt_hdr_t *)pdu->isp_hdr;
1366 
1367 	ASSERT(icp != NULL);
1368 	ASSERT(pdu != NULL);
1369 	ASSERT(isp != NULL);
1370 
1371 	mutex_enter(&isp->sess_cmdsn_mutex);
1372 	if (icp->conn_expstatsn == ntohl(iaehp->statsn)) {
1373 		icp->conn_expstatsn++;
1374 	} else {
1375 		cmn_err(CE_WARN, "iscsi connection(%u) protocol error - "
1376 		    "received status out of order statsn:0x%x "
1377 		    "expstatsn:0x%x", icp->conn_oid,
1378 		    ntohl(iaehp->statsn), icp->conn_expstatsn);
1379 		mutex_exit(&isp->sess_cmdsn_mutex);
1380 		return (IDM_STATUS_PROTOCOL_ERROR);
1381 	}
1382 	mutex_exit(&isp->sess_cmdsn_mutex);
1383 
1384 	switch (iaehp->async_event) {
1385 	case ISCSI_ASYNC_EVENT_SCSI_EVENT:
1386 		/*
1387 		 * SCSI asynchronous event is reported in
1388 		 * the sense data.  Sense data that accompanies
1389 		 * the report in the data segment identifies the
1390 		 * condition.  If the target supports SCSI
1391 		 * asynchronous events reporting (see [SAM2])
1392 		 * as indicated in the stardard INQUIRY data
1393 		 * (see [SPC3]), its use may be enabled by
1394 		 * parameters in the SCSI control mode page
1395 		 * (see [SPC3]).
1396 		 *
1397 		 * T-10 has removed SCSI asunchronous events
1398 		 * from the standard.  Although we have seen
1399 		 * a couple targets still spending these requests.
1400 		 * Those targets were specifically sending them
1401 		 * for notification of a LUN/Volume change
1402 		 * (ex. LUN addition/removal).  Take a general
1403 		 * action to these events of dis/reconnecting.
1404 		 * Once reconnected we perform a reenumeration.
1405 		 */
1406 		idm_ini_conn_disconnect(ic);
1407 		break;
1408 
1409 	case ISCSI_ASYNC_EVENT_REQUEST_LOGOUT:
1410 		/*
1411 		 * We've been asked to logout by the target --
1412 		 * we need to treat this differently from a normal logout
1413 		 * due to a discovery failure.  Normal logouts result in
1414 		 * an N3 event to the session state machine and an offline
1415 		 * of the lun.  In this case we want to put the connection
1416 		 * into "failed" state and generate N5 to the session state
1417 		 * machine since the initiator logged out at the target's
1418 		 * request.  To track this we set a flag indicating we
1419 		 * received this async logout request from the tharget
1420 		 */
1421 		mutex_enter(&icp->conn_state_mutex);
1422 		icp->conn_async_logout = B_TRUE;
1423 		mutex_exit(&icp->conn_state_mutex);
1424 
1425 		/* Target has requested this connection to logout. */
1426 		itp = kmem_zalloc(sizeof (iscsi_task_t), KM_SLEEP);
1427 		itp->t_arg = icp;
1428 		itp->t_blocking = B_FALSE;
1429 		if (ddi_taskq_dispatch(isp->sess_taskq,
1430 		    (void(*)())iscsi_logout_start, itp, DDI_SLEEP) !=
1431 		    DDI_SUCCESS) {
1432 			/* Disconnect if we couldn't dispatch the task */
1433 			idm_ini_conn_disconnect(ic);
1434 		}
1435 		break;
1436 
1437 	case ISCSI_ASYNC_EVENT_DROPPING_CONNECTION:
1438 		/*
1439 		 * Target is going to drop our connection.
1440 		 *	param1 - CID which will be dropped.
1441 		 *	param2 - Min time to reconnect.
1442 		 *	param3 - Max time to reconnect.
1443 		 *
1444 		 * For now just let fail as another disconnect.
1445 		 *
1446 		 * MC/S Once we support > 1 connections then
1447 		 * we need to check the CID and drop that
1448 		 * specific connection.
1449 		 */
1450 		iscsi_conn_set_login_min_max(icp, iaehp->param2,
1451 		    iaehp->param3);
1452 		idm_ini_conn_disconnect(ic);
1453 		break;
1454 
1455 	case ISCSI_ASYNC_EVENT_DROPPING_ALL_CONNECTIONS:
1456 		/*
1457 		 * Target is going to drop ALL connections.
1458 		 *	param2 - Min time to reconnect.
1459 		 *	param3 - Max time to reconnect.
1460 		 *
1461 		 * For now just let fail as anyother disconnect.
1462 		 *
1463 		 * MC/S Once we support more than > 1 connections
1464 		 * then we need to drop all connections on the
1465 		 * session.
1466 		 */
1467 		iscsi_conn_set_login_min_max(icp, iaehp->param2,
1468 		    iaehp->param3);
1469 		idm_ini_conn_disconnect(ic);
1470 		break;
1471 
1472 	case ISCSI_ASYNC_EVENT_PARAM_NEGOTIATION:
1473 		/*
1474 		 * Target requests parameter negotiation
1475 		 * on this connection.
1476 		 *
1477 		 * The initiator must honor this request.  For
1478 		 * now we will request a logout.  We can't
1479 		 * just ignore this or it might force corruption?
1480 		 */
1481 		itp = kmem_zalloc(sizeof (iscsi_task_t), KM_SLEEP);
1482 		itp->t_arg = icp;
1483 		itp->t_blocking = B_FALSE;
1484 		if (ddi_taskq_dispatch(isp->sess_taskq,
1485 		    (void(*)())iscsi_logout_start, itp, DDI_SLEEP) !=
1486 		    DDI_SUCCESS) {
1487 			/* Disconnect if we couldn't dispatch the task */
1488 			idm_ini_conn_disconnect(ic);
1489 		}
1490 		break;
1491 
1492 	case ISCSI_ASYNC_EVENT_VENDOR_SPECIFIC:
1493 		/*
1494 		 * We currently don't handle any vendor
1495 		 * specific async events.  So just ignore
1496 		 * the request.
1497 		 */
1498 		idm_ini_conn_disconnect(ic);
1499 		break;
1500 	default:
1501 		rval = IDM_STATUS_PROTOCOL_ERROR;
1502 	}
1503 
1504 	return (rval);
1505 }
1506 
1507 /*
1508  * iscsi_rx_process_text_rsp - processes iSCSI text response.  It sets
1509  * the cmd_result field of the command data structure with the actual
1510  * status value instead of returning the status value.  The return value
1511  * is SUCCESS in order to let iscsi_handle_text control the operation of
1512  * a text request.
1513  * Text requests are a handled a little different than other types of
1514  * iSCSI commands because the initiator sends additional empty text requests
1515  * in order to obtain the remaining responses required to complete the
1516  * request.  iscsi_handle_text controls the operation of text request, while
1517  * iscsi_rx_process_text_rsp just process the current response.
1518  */
1519 static idm_status_t
1520 iscsi_rx_process_text_rsp(idm_conn_t *ic, idm_pdu_t *pdu)
1521 {
1522 	iscsi_sess_t		*isp	= NULL;
1523 	iscsi_text_rsp_hdr_t	*ithp	=
1524 	    (iscsi_text_rsp_hdr_t *)pdu->isp_hdr;
1525 	iscsi_conn_t		*icp	= ic->ic_handle;
1526 	iscsi_cmd_t		*icmdp	= NULL;
1527 	boolean_t		final	= B_FALSE;
1528 	uint32_t		data_len;
1529 	uint8_t			*data = pdu->isp_data;
1530 	idm_status_t		rval;
1531 
1532 	isp = icp->conn_sess;
1533 
1534 	mutex_enter(&icp->conn_queue_active.mutex);
1535 	if ((rval = iscsi_rx_chk(icp, isp, (iscsi_scsi_rsp_hdr_t *)ithp,
1536 	    &icmdp)) != IDM_STATUS_SUCCESS) {
1537 		mutex_exit(&icp->conn_queue_active.mutex);
1538 		return (rval);
1539 	}
1540 
1541 	/* update local final response flag */
1542 	if (ithp->flags & ISCSI_FLAG_FINAL) {
1543 		final = B_TRUE;
1544 	}
1545 
1546 	/*
1547 	 * validate received TTT value.  RFC3720 specifies the following:
1548 	 * - F bit set to 1 MUST have a reserved TTT value 0xffffffff
1549 	 * - F bit set to 0 MUST have a non-reserved TTT value !0xffffffff
1550 	 * In addition, the received TTT value must not change between
1551 	 * responses of a long text response
1552 	 */
1553 	if (((final == B_TRUE) && (ithp->ttt != ISCSI_RSVD_TASK_TAG)) ||
1554 	    ((final == B_FALSE) && (ithp->ttt == ISCSI_RSVD_TASK_TAG))) {
1555 		icmdp->cmd_result = ISCSI_STATUS_PROTOCOL_ERROR;
1556 		icmdp->cmd_un.text.stage = ISCSI_CMD_TEXT_FINAL_RSP;
1557 		mutex_exit(&icp->conn_queue_active.mutex);
1558 		cmn_err(CE_WARN, "iscsi connection(%u) protocol error - "
1559 		    "received text response with invalid flags:0x%x or "
1560 		    "ttt:0x%x", icp->conn_oid, ithp->flags, ithp->itt);
1561 		return (IDM_STATUS_PROTOCOL_ERROR);
1562 	}
1563 
1564 	if ((icmdp->cmd_un.text.stage == ISCSI_CMD_TEXT_INITIAL_REQ) &&
1565 	    (ithp->ttt == ISCSI_RSVD_TASK_TAG) &&
1566 	    (final == B_FALSE)) {
1567 		/* TTT should have matched reserved value */
1568 		icmdp->cmd_result = ISCSI_STATUS_PROTOCOL_ERROR;
1569 		icmdp->cmd_un.text.stage = ISCSI_CMD_TEXT_FINAL_RSP;
1570 		mutex_exit(&icp->conn_queue_active.mutex);
1571 		cmn_err(CE_WARN, "iscsi connection(%u) protocol "
1572 		    "error - received text response with invalid "
1573 		    "ttt:0x%x", icp->conn_oid, ithp->ttt);
1574 		return (IDM_STATUS_PROTOCOL_ERROR);
1575 	}
1576 
1577 	/*
1578 	 * If this is first response, save away TTT value for later use
1579 	 * in a long text request/response sequence
1580 	 */
1581 	if (icmdp->cmd_un.text.stage == ISCSI_CMD_TEXT_INITIAL_REQ) {
1582 		icmdp->cmd_un.text.ttt = ithp->ttt;
1583 	}
1584 
1585 	data_len = ntoh24(ithp->dlength);
1586 
1587 	/* check whether enough buffer available to copy data */
1588 	if ((icmdp->cmd_un.text.total_rx_len + data_len) >
1589 	    icmdp->cmd_un.text.buf_len) {
1590 		icmdp->cmd_un.text.total_rx_len += data_len;
1591 		icmdp->cmd_result = ISCSI_STATUS_DATA_OVERFLOW;
1592 		/*
1593 		 * DATA_OVERFLOW will result in a SUCCESS return so that
1594 		 * iscsi_handle_text can continue to obtain the remaining
1595 		 * text response if needed.
1596 		 */
1597 	} else {
1598 		char *buf_data = (icmdp->cmd_un.text.buf +
1599 		    icmdp->cmd_un.text.offset);
1600 
1601 		bcopy(data, buf_data, data_len);
1602 		icmdp->cmd_un.text.offset += data_len;
1603 		icmdp->cmd_un.text.total_rx_len += data_len;
1604 		icmdp->cmd_result = ISCSI_STATUS_SUCCESS;
1605 		bcopy(ithp->rsvd4, icmdp->cmd_un.text.lun,
1606 		    sizeof (icmdp->cmd_un.text.lun));
1607 	}
1608 
1609 	/* update stage  */
1610 	if (final == B_TRUE) {
1611 		icmdp->cmd_un.text.stage = ISCSI_CMD_TEXT_FINAL_RSP;
1612 	} else {
1613 		icmdp->cmd_un.text.stage = ISCSI_CMD_TEXT_CONTINUATION;
1614 	}
1615 
1616 	iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E3, isp);
1617 	mutex_exit(&icp->conn_queue_active.mutex);
1618 	return (IDM_STATUS_SUCCESS);
1619 }
1620 
1621 /*
1622  * iscsi_rx_process_scsi_itt_to_icmdp - Lookup itt using IDM to find matching
1623  * icmdp.  Verify itt in hdr and icmdp are the same.
1624  */
1625 static iscsi_status_t
1626 iscsi_rx_process_scsi_itt_to_icmdp(iscsi_sess_t *isp, idm_conn_t *ic,
1627     iscsi_scsi_rsp_hdr_t *ihp, iscsi_cmd_t **icmdp)
1628 {
1629 	idm_task_t *itp;
1630 
1631 	ASSERT(isp != NULL);
1632 	ASSERT(ihp != NULL);
1633 	ASSERT(icmdp != NULL);
1634 	ASSERT(mutex_owned(&isp->sess_cmdsn_mutex));
1635 	itp = idm_task_find_and_complete(ic, ihp->itt, ISCSI_INI_TASK_TTT);
1636 	if (itp == NULL) {
1637 		cmn_err(CE_WARN, "iscsi session(%u) protocol error - "
1638 		    "received unknown itt:0x%x - protocol error",
1639 		    isp->sess_oid, ihp->itt);
1640 		return (ISCSI_STATUS_INTERNAL_ERROR);
1641 	}
1642 	*icmdp = itp->idt_private;
1643 
1644 	idm_task_rele(itp);
1645 
1646 	return (ISCSI_STATUS_SUCCESS);
1647 
1648 }
1649 
1650 /*
1651  * iscsi_rx_process_itt_to_icmdp - Lookup itt in the session's
1652  * cmd table to find matching icmdp.  Verify itt in hdr and
1653  * icmdp are the same.
1654  */
1655 static iscsi_status_t
1656 iscsi_rx_process_itt_to_icmdp(iscsi_sess_t *isp, iscsi_hdr_t *ihp,
1657     iscsi_cmd_t **icmdp)
1658 {
1659 	int cmd_table_idx = 0;
1660 
1661 	ASSERT(isp != NULL);
1662 	ASSERT(ihp != NULL);
1663 	ASSERT(icmdp != NULL);
1664 	ASSERT(mutex_owned(&isp->sess_cmdsn_mutex));
1665 
1666 	/* try to find an associated iscsi_pkt */
1667 	cmd_table_idx = (ihp->itt - IDM_TASKIDS_MAX) % ISCSI_CMD_TABLE_SIZE;
1668 	if (isp->sess_cmd_table[cmd_table_idx] == NULL) {
1669 		cmn_err(CE_WARN, "iscsi session(%u) protocol error - "
1670 		    "received unknown itt:0x%x - protocol error",
1671 		    isp->sess_oid, ihp->itt);
1672 		return (ISCSI_STATUS_INTERNAL_ERROR);
1673 	}
1674 
1675 	/* verify itt */
1676 	if (isp->sess_cmd_table[cmd_table_idx]->cmd_itt != ihp->itt) {
1677 		cmn_err(CE_WARN, "iscsi session(%u) received itt:0x%x "
1678 		    " which is out of sync with itt:0x%x", isp->sess_oid,
1679 		    ihp->itt, isp->sess_cmd_table[cmd_table_idx]->cmd_itt);
1680 		return (ISCSI_STATUS_INTERNAL_ERROR);
1681 	}
1682 
1683 	/* ensure that icmdp is still in Active state */
1684 	if (isp->sess_cmd_table[cmd_table_idx]->cmd_state !=
1685 	    ISCSI_CMD_STATE_ACTIVE) {
1686 		cmn_err(CE_WARN, "iscsi session(%u) received itt:0x%x "
1687 		    "but icmdp (%p) is not in active state",
1688 		    isp->sess_oid, ihp->itt,
1689 		    (void *)isp->sess_cmd_table[cmd_table_idx]);
1690 		return (ISCSI_STATUS_INTERNAL_ERROR);
1691 	}
1692 
1693 	/* make sure this is a SCSI cmd */
1694 	*icmdp = isp->sess_cmd_table[cmd_table_idx];
1695 
1696 	return (ISCSI_STATUS_SUCCESS);
1697 }
1698 
1699 /*
1700  * +--------------------------------------------------------------------+
1701  * | End of protocol receive routines					|
1702  * +--------------------------------------------------------------------+
1703  */
1704 
1705 /*
1706  * +--------------------------------------------------------------------+
1707  * | Beginning of protocol send routines				|
1708  * +--------------------------------------------------------------------+
1709  */
1710 
1711 
1712 /*
1713  * iscsi_tx_thread - This thread is the driving point for all
1714  * iSCSI PDUs after login.  No PDUs should call idm_pdu_tx()
1715  * directly they should be funneled through iscsi_tx_thread.
1716  */
1717 void
1718 iscsi_tx_thread(iscsi_thread_t *thread, void *arg)
1719 {
1720 	iscsi_conn_t	*icp	= (iscsi_conn_t *)arg;
1721 	iscsi_sess_t	*isp	= NULL;
1722 	iscsi_cmd_t	*icmdp	= NULL;
1723 	clock_t		tout;
1724 	int		ret	= 1;
1725 
1726 	ASSERT(icp != NULL);
1727 	isp = icp->conn_sess;
1728 	ASSERT(isp != NULL);
1729 	ASSERT(thread != NULL);
1730 	ASSERT(thread->signature == SIG_ISCSI_THREAD);
1731 
1732 	tout = SEC_TO_TICK(1);
1733 	/*
1734 	 * Transfer icmdps until shutdown by owning session.
1735 	 */
1736 	while (ret != 0) {
1737 
1738 		isp->sess_window_open = B_TRUE;
1739 		/*
1740 		 * While the window is open, there are commands available
1741 		 * to send and the session state allows those commands to
1742 		 * be sent try to transfer them.
1743 		 */
1744 		mutex_enter(&isp->sess_queue_pending.mutex);
1745 		while ((isp->sess_window_open == B_TRUE) &&
1746 		    ((icmdp = isp->sess_queue_pending.head) != NULL) &&
1747 		    (((icmdp->cmd_type != ISCSI_CMD_TYPE_SCSI) &&
1748 		    (ISCSI_CONN_STATE_FULL_FEATURE(icp->conn_state))) ||
1749 		    (icp->conn_state == ISCSI_CONN_STATE_LOGGED_IN))) {
1750 
1751 			/* update command with this connection info */
1752 			icmdp->cmd_conn = icp;
1753 			/* attempt to send this command */
1754 			iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E2, isp);
1755 
1756 			ASSERT(!mutex_owned(&isp->sess_queue_pending.mutex));
1757 			mutex_enter(&isp->sess_queue_pending.mutex);
1758 		}
1759 		mutex_exit(&isp->sess_queue_pending.mutex);
1760 
1761 		/*
1762 		 * Go to sleep until there is something new
1763 		 * to process (awoken via cv_boardcast).
1764 		 * Or the timer goes off.
1765 		 */
1766 		ret = iscsi_thread_wait(thread, tout);
1767 	}
1768 
1769 }
1770 
1771 
1772 /*
1773  * iscsi_tx_cmd - transfers icmdp across wire as iscsi pdu
1774  *
1775  * Just prior to sending the command to the networking layer the
1776  * pending queue lock will be dropped.  At this point only local
1777  * resources will be used, not the icmdp.  Holding the queue lock
1778  * across the networking call can lead to a hang.  (This is due
1779  * to the the target driver and networking layers competing use
1780  * of the timeout() resources and the queue lock being held for
1781  * both sides.)  Upon the completion of this command the lock
1782  * will have been re-acquired.
1783  */
1784 iscsi_status_t
1785 iscsi_tx_cmd(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
1786 {
1787 	iscsi_status_t	rval = ISCSI_STATUS_INTERNAL_ERROR;
1788 
1789 	ASSERT(isp != NULL);
1790 	ASSERT(icmdp != NULL);
1791 
1792 	/* transfer specific command type */
1793 	switch (icmdp->cmd_type) {
1794 	case ISCSI_CMD_TYPE_SCSI:
1795 		rval = iscsi_tx_scsi(isp, icmdp);
1796 		break;
1797 	case ISCSI_CMD_TYPE_NOP:
1798 		rval = iscsi_tx_nop(isp, icmdp);
1799 		break;
1800 	case ISCSI_CMD_TYPE_ABORT:
1801 		rval = iscsi_tx_abort(isp, icmdp);
1802 		break;
1803 	case ISCSI_CMD_TYPE_RESET:
1804 		rval = iscsi_tx_reset(isp, icmdp);
1805 		break;
1806 	case ISCSI_CMD_TYPE_LOGOUT:
1807 		rval = iscsi_tx_logout(isp, icmdp);
1808 		break;
1809 	case ISCSI_CMD_TYPE_TEXT:
1810 		rval = iscsi_tx_text(isp, icmdp);
1811 		break;
1812 	default:
1813 		cmn_err(CE_WARN, "iscsi_tx_cmd: invalid cmdtype: %d",
1814 		    icmdp->cmd_type);
1815 		ASSERT(FALSE);
1816 	}
1817 
1818 	ASSERT(!mutex_owned(&isp->sess_queue_pending.mutex));
1819 	return (rval);
1820 }
1821 
1822 /*
1823  * a variable length cdb can be up to 16K, but we obviously don't want
1824  * to put that on the stack; go with 200 bytes; if we get something
1825  * bigger than that we will kmem_alloc a buffer
1826  */
1827 #define	DEF_CDB_LEN	200
1828 
1829 /*
1830  * given the size of the cdb, return how many bytes the header takes,
1831  * which is the sizeof addl_hdr_t + the CDB size, minus the 16 bytes
1832  * stored in the basic header, minus sizeof (ahs_extscb)
1833  */
1834 #define	ADDLHDRSZ(x)		(sizeof (iscsi_addl_hdr_t) + (x) - \
1835 					16 - 4)
1836 
1837 static void
1838 iscsi_tx_init_hdr(iscsi_sess_t *isp, iscsi_conn_t *icp,
1839     iscsi_text_hdr_t *ihp, int opcode, iscsi_cmd_t *icmdp)
1840 {
1841 	ihp->opcode		= opcode;
1842 	ihp->itt		= icmdp->cmd_itt;
1843 	mutex_enter(&isp->sess_cmdsn_mutex);
1844 	icmdp->cmd_sn		= isp->sess_cmdsn;
1845 	ihp->cmdsn		= htonl(isp->sess_cmdsn);
1846 	isp->sess_cmdsn++;
1847 	mutex_exit(&isp->sess_cmdsn_mutex);
1848 	ihp->expstatsn		= htonl(icp->conn_expstatsn);
1849 	icp->conn_laststatsn = icp->conn_expstatsn;
1850 }
1851 
1852 
1853 static void
1854 iscsi_tx_scsi_data(iscsi_cmd_t *icmdp, iscsi_scsi_cmd_hdr_t *ihp,
1855     iscsi_conn_t *icp, idm_pdu_t *pdu)
1856 {
1857 	struct buf		*bp		= NULL;
1858 	size_t			buflen		= 0;
1859 	uint32_t		first_burst_length = 0;
1860 	struct scsi_pkt		*pkt;
1861 
1862 	pkt = icmdp->cmd_un.scsi.pkt;
1863 	bp = icmdp->cmd_un.scsi.bp;
1864 	if ((bp != NULL) && bp->b_bcount) {
1865 		buflen = bp->b_bcount;
1866 		first_burst_length =
1867 		    icp->conn_params.first_burst_length;
1868 
1869 		if (bp->b_flags & B_READ) {
1870 			ihp->flags = ISCSI_FLAG_FINAL;
1871 			/*
1872 			 * fix problem where OS sends bp (B_READ &
1873 			 * b_bcount!=0) for a TUR or START_STOP.
1874 			 * (comment came from cisco code.)
1875 			 */
1876 			if ((pkt->pkt_cdbp[0] != SCMD_TEST_UNIT_READY) &&
1877 			    (pkt->pkt_cdbp[0] != SCMD_START_STOP)) {
1878 				ihp->flags |= ISCSI_FLAG_CMD_READ;
1879 				ihp->data_length = htonl(buflen);
1880 			}
1881 		} else {
1882 			ihp->flags = ISCSI_FLAG_CMD_WRITE;
1883 			/*
1884 			 * FinalBit on the the iSCSI PDU denotes this
1885 			 * is the last PDU in the sequence.
1886 			 *
1887 			 * initial_r2t = true means R2T is required
1888 			 * for additional PDU, so there will be no more
1889 			 * unsolicited PDUs following
1890 			 */
1891 			if (icp->conn_params.initial_r2t) {
1892 				ihp->flags |= ISCSI_FLAG_FINAL;
1893 			}
1894 
1895 			/* Check if we should send ImmediateData */
1896 			if (icp->conn_params.immediate_data) {
1897 				pdu->isp_data =
1898 				    (uint8_t *)icmdp->
1899 				    cmd_un.scsi.bp->b_un.b_addr;
1900 
1901 				pdu->isp_datalen = MIN(MIN(buflen,
1902 				    first_burst_length),
1903 				    icmdp->cmd_conn->conn_params.
1904 				    max_xmit_data_seg_len);
1905 
1906 				/*
1907 				 * if everything fits immediate, or
1908 				 * we can send all burst data immediate
1909 				 * (not unsol), set F
1910 				 */
1911 				/*
1912 				 * XXX This doesn't look right -- it's not
1913 				 * clear how we can handle transmitting
1914 				 * any unsolicited data.  It looks like
1915 				 * we only support immediate data.  So what
1916 				 * happens if we don't set ISCSI_FLAG_FINAL?
1917 				 *
1918 				 * Unless there's magic code somewhere that
1919 				 * is sending the remaining PDU's we should
1920 				 * simply set ISCSI_FLAG_FINAL and forget
1921 				 * about sending unsolicited data.  The big
1922 				 * win is the immediate data anyway for small
1923 				 * PDU's.
1924 				 */
1925 				if ((pdu->isp_datalen == buflen) ||
1926 				    (pdu->isp_datalen == first_burst_length)) {
1927 					ihp->flags |= ISCSI_FLAG_FINAL;
1928 				}
1929 
1930 				hton24(ihp->dlength, pdu->isp_datalen);
1931 			}
1932 			/* total data transfer length */
1933 			ihp->data_length = htonl(buflen);
1934 		}
1935 	} else {
1936 		ihp->flags = ISCSI_FLAG_FINAL;
1937 	}
1938 	icmdp->cmd_un.scsi.data_transferred += pdu->isp_datalen;
1939 	/* XXX How is this different from the code above? */
1940 	/* will idm send the next data command up to burst length? */
1941 	/* send the burstlen if we haven't sent immediate data */
1942 	/* CRM: should idm send difference min(buflen, first_burst) and  imm? */
1943 	/*    (MIN(first_burst_length, buflen) - imdata > 0) */
1944 	/* CRM_LATER: change this to generate unsolicited pdu */
1945 	if ((buflen > 0) &&
1946 	    ((bp->b_flags & B_READ) == 0) &&
1947 	    (icp->conn_params.initial_r2t == 0) &&
1948 	    pdu->isp_datalen == 0) {
1949 
1950 		pdu->isp_datalen = MIN(first_burst_length, buflen);
1951 		if ((pdu->isp_datalen == buflen) ||
1952 		    (pdu->isp_datalen == first_burst_length)) {
1953 			ihp->flags |= ISCSI_FLAG_FINAL;
1954 		}
1955 		pdu->isp_data = (uint8_t *)icmdp->cmd_un.scsi.bp->b_un.b_addr;
1956 		hton24(ihp->dlength, pdu->isp_datalen);
1957 	}
1958 }
1959 
1960 static void
1961 iscsi_tx_scsi_init_pkt(iscsi_cmd_t *icmdp, iscsi_scsi_cmd_hdr_t *ihp)
1962 {
1963 	struct scsi_pkt *pkt;
1964 
1965 	pkt = icmdp->cmd_un.scsi.pkt;
1966 	pkt->pkt_state = (STATE_GOT_BUS | STATE_GOT_TARGET);
1967 	pkt->pkt_reason = CMD_INCOMPLETE;
1968 
1969 	/* tagged queuing */
1970 	if (pkt->pkt_flags & FLAG_HTAG) {
1971 		ihp->flags |= ISCSI_ATTR_HEAD_OF_QUEUE;
1972 	} else if (pkt->pkt_flags & FLAG_OTAG) {
1973 		ihp->flags |= ISCSI_ATTR_ORDERED;
1974 	} else if (pkt->pkt_flags & FLAG_STAG) {
1975 		ihp->flags |= ISCSI_ATTR_SIMPLE;
1976 	} else {
1977 		/* ihp->flags |= ISCSI_ATTR_UNTAGGED; */
1978 		/* EMPTY */
1979 	}
1980 
1981 	/* iscsi states lun is based on spc.2 */
1982 	ISCSI_LUN_BYTE_COPY(ihp->lun, icmdp->cmd_un.scsi.lun);
1983 
1984 	if (icmdp->cmd_un.scsi.cmdlen <= 16) {
1985 		/* copy the SCSI Command Block into the PDU */
1986 		bcopy(pkt->pkt_cdbp, ihp->scb,
1987 		    icmdp->cmd_un.scsi.cmdlen);
1988 	} else {
1989 		iscsi_addl_hdr_t *iahp;
1990 
1991 		iahp = (iscsi_addl_hdr_t *)ihp;
1992 
1993 		ihp->hlength = (ADDLHDRSZ(icmdp->cmd_un.scsi.cmdlen) -
1994 		    sizeof (iscsi_scsi_cmd_hdr_t) + 3) / 4;
1995 		iahp->ahs_hlen_hi = 0;
1996 		iahp->ahs_hlen_lo = (icmdp->cmd_un.scsi.cmdlen - 15);
1997 		iahp->ahs_key = 0x01;
1998 		iahp->ahs_resv = 0;
1999 		bcopy(pkt->pkt_cdbp, ihp->scb, 16);
2000 		bcopy(((char *)pkt->pkt_cdbp) + 16, &iahp->ahs_extscb[0],
2001 		    icmdp->cmd_un.scsi.cmdlen);
2002 	}
2003 
2004 	/*
2005 	 * Update all values before transfering.
2006 	 * We should never touch the icmdp after
2007 	 * transfering if there is no more data
2008 	 * to send.  The only case the idm_pdu_tx()
2009 	 * will fail is a on a connection disconnect
2010 	 * in that case the command will be flushed.
2011 	 */
2012 	pkt->pkt_state |= STATE_SENT_CMD;
2013 }
2014 
2015 static void
2016 iscsi_tx_scsi_init_task(iscsi_cmd_t *icmdp, iscsi_conn_t *icp,
2017     iscsi_scsi_cmd_hdr_t *ihp)
2018 {
2019 	idm_task_t		*itp;
2020 	struct buf		*bp		= NULL;
2021 	uint32_t		data_length;
2022 
2023 	bp = icmdp->cmd_un.scsi.bp;
2024 
2025 	itp = icmdp->cmd_itp;
2026 	ASSERT(itp != NULL);
2027 	data_length = ntohl(ihp->data_length);
2028 	ISCSI_IO_LOG(CE_NOTE,
2029 	    "DEBUG: iscsi_tx_init_task: task_start: %p idt_tt: %x cmdsn: %x "
2030 	    "sess_cmdsn: %x cmd: %p "
2031 	    "cmdtype: %d datalen: %u",
2032 	    (void *)itp, itp->idt_tt, ihp->cmdsn, icp->conn_sess->sess_cmdsn,
2033 	    (void *)icmdp, icmdp->cmd_type, data_length);
2034 	if (data_length > 0) {
2035 		if (bp->b_flags & B_READ) {
2036 			icmdp->cmd_un.scsi.ibp_ibuf =
2037 			    idm_buf_alloc(icp->conn_ic,
2038 			    bp->b_un.b_addr, bp->b_bcount);
2039 			if (icmdp->cmd_un.scsi.ibp_ibuf)
2040 				idm_buf_bind_in(itp,
2041 				    icmdp->cmd_un.scsi.ibp_ibuf);
2042 		} else {
2043 			icmdp->cmd_un.scsi.ibp_obuf =
2044 			    idm_buf_alloc(icp->conn_ic,
2045 			    bp->b_un.b_addr, bp->b_bcount);
2046 			if (icmdp->cmd_un.scsi.ibp_obuf)
2047 				idm_buf_bind_out(itp,
2048 				    icmdp->cmd_un.scsi.ibp_obuf);
2049 		}
2050 		ISCSI_IO_LOG(CE_NOTE,
2051 		    "DEBUG: pdu_tx: task_start(%s): %p ic: %p idt_tt: %x "
2052 		    "cmdsn: %x sess_cmdsn: %x sess_expcmdsn: %x obuf: %p "
2053 		    "cmdp: %p cmdtype: %d "
2054 		    "buflen: %lu " "bpaddr: %p datalen: %u ",
2055 		    bp->b_flags & B_READ ? "B_READ" : "B_WRITE",
2056 		    (void *)itp, (void *)icp->conn_ic,
2057 		    itp->idt_tt, ihp->cmdsn,
2058 		    icp->conn_sess->sess_cmdsn,
2059 		    icp->conn_sess->sess_expcmdsn,
2060 		    (void *)icmdp->cmd_un.scsi.ibp_ibuf,
2061 		    (void *)icmdp, icmdp->cmd_type, bp->b_bcount,
2062 		    (void *)bp->b_un.b_addr,
2063 		    data_length);
2064 	}
2065 
2066 	/*
2067 	 * Task is now active
2068 	 */
2069 	idm_task_start(itp, ISCSI_INI_TASK_TTT);
2070 }
2071 
2072 /*
2073  * iscsi_tx_scsi -
2074  *
2075  */
2076 static iscsi_status_t
2077 iscsi_tx_scsi(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
2078 {
2079 	iscsi_status_t		rval		= ISCSI_STATUS_SUCCESS;
2080 	iscsi_conn_t		*icp		= NULL;
2081 	struct scsi_pkt		*pkt		= NULL;
2082 	iscsi_scsi_cmd_hdr_t	*ihp		= NULL;
2083 	int			cdblen		= 0;
2084 	idm_pdu_t		*pdu;
2085 	int			len;
2086 
2087 	ASSERT(isp != NULL);
2088 	ASSERT(icmdp != NULL);
2089 
2090 	pdu = kmem_zalloc(sizeof (idm_pdu_t), KM_SLEEP);
2091 
2092 	pkt = icmdp->cmd_un.scsi.pkt;
2093 	ASSERT(pkt != NULL);
2094 	icp = icmdp->cmd_conn;
2095 	ASSERT(icp != NULL);
2096 
2097 	/* Reset counts in case we are on a retry */
2098 	icmdp->cmd_un.scsi.data_transferred = 0;
2099 
2100 	if (icmdp->cmd_un.scsi.cmdlen > DEF_CDB_LEN) {
2101 		cdblen = icmdp->cmd_un.scsi.cmdlen;
2102 		ihp = kmem_zalloc(ADDLHDRSZ(cdblen), KM_SLEEP);
2103 		len = ADDLHDRSZ(cdblen);
2104 	} else {
2105 		/*
2106 		 * only bzero the basic header; the additional header
2107 		 * will be set up correctly later, if needed
2108 		 */
2109 		ihp = kmem_zalloc(sizeof (iscsi_scsi_cmd_hdr_t), KM_SLEEP);
2110 		len = sizeof (iscsi_scsi_cmd_hdr_t);
2111 	}
2112 
2113 	iscsi_tx_init_hdr(isp, icp, (iscsi_text_hdr_t *)ihp,
2114 	    ISCSI_OP_SCSI_CMD, icmdp);
2115 
2116 	idm_pdu_init(pdu, icp->conn_ic, (void *)icmdp, &iscsi_tx_done);
2117 	idm_pdu_init_hdr(pdu, (uint8_t *)ihp, len);
2118 	pdu->isp_data = NULL;
2119 	pdu->isp_datalen = 0;
2120 
2121 	/*
2122 	 * Sestion 12.11 of the iSCSI specification has a good table
2123 	 * describing when uncolicited data and/or immediate data
2124 	 * should be sent.
2125 	 */
2126 
2127 	iscsi_tx_scsi_data(icmdp, ihp, icp, pdu);
2128 
2129 	iscsi_tx_scsi_init_pkt(icmdp, ihp);
2130 
2131 	/* Calls idm_task_start */
2132 	iscsi_tx_scsi_init_task(icmdp, icp, ihp);
2133 
2134 	mutex_exit(&isp->sess_queue_pending.mutex);
2135 
2136 	idm_pdu_tx(pdu);
2137 
2138 	icmdp->cmd_misc_flags |= ISCSI_CMD_MISCFLAG_SENT;
2139 
2140 	return (rval);
2141 }
2142 
2143 
2144 /* ARGSUSED */
2145 static void
2146 iscsi_tx_done(idm_pdu_t *pdu, idm_status_t status)
2147 {
2148 	kmem_free((iscsi_hdr_t *)pdu->isp_hdr, pdu->isp_hdrlen);
2149 	kmem_free(pdu, sizeof (idm_pdu_t));
2150 }
2151 
2152 
2153 static void
2154 iscsi_tx_pdu(iscsi_conn_t *icp, int opcode, void *hdr, int hdrlen,
2155     iscsi_cmd_t *icmdp)
2156 {
2157 	idm_pdu_t	*tx_pdu;
2158 	iscsi_hdr_t	*ihp = (iscsi_hdr_t *)hdr;
2159 
2160 	tx_pdu = kmem_zalloc(sizeof (idm_pdu_t), KM_SLEEP);
2161 	ASSERT(tx_pdu != NULL);
2162 
2163 	idm_pdu_init(tx_pdu, icp->conn_ic, icmdp, &iscsi_tx_done);
2164 	idm_pdu_init_hdr(tx_pdu, hdr, hdrlen);
2165 	if (opcode == ISCSI_OP_TEXT_CMD) {
2166 		idm_pdu_init_data(tx_pdu,
2167 		    (uint8_t *)icmdp->cmd_un.text.buf,
2168 		    ntoh24(ihp->dlength));
2169 	}
2170 
2171 	mutex_exit(&icp->conn_sess->sess_queue_pending.mutex);
2172 	idm_pdu_tx(tx_pdu);
2173 	icmdp->cmd_misc_flags |= ISCSI_CMD_MISCFLAG_SENT;
2174 }
2175 
2176 
2177 /*
2178  * iscsi_tx_nop -
2179  *
2180  */
2181 static iscsi_status_t
2182 iscsi_tx_nop(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
2183 {
2184 	iscsi_status_t		rval	= ISCSI_STATUS_SUCCESS;
2185 	iscsi_conn_t		*icp	= NULL;
2186 	iscsi_nop_out_hdr_t	*inohp;
2187 
2188 	ASSERT(isp != NULL);
2189 	ASSERT(icmdp != NULL);
2190 	icp = icmdp->cmd_conn;
2191 	ASSERT(icp != NULL);
2192 
2193 	inohp = kmem_zalloc(sizeof (iscsi_nop_out_hdr_t), KM_SLEEP);
2194 	ASSERT(inohp != NULL);
2195 
2196 	inohp->opcode	= ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
2197 	inohp->flags	= ISCSI_FLAG_FINAL;
2198 	inohp->itt	= icmdp->cmd_itt;
2199 	inohp->ttt	= icmdp->cmd_ttt;
2200 	mutex_enter(&isp->sess_cmdsn_mutex);
2201 	icmdp->cmd_sn	= isp->sess_cmdsn;
2202 	inohp->cmdsn	= htonl(isp->sess_cmdsn);
2203 	mutex_exit(&isp->sess_cmdsn_mutex);
2204 	inohp->expstatsn	= htonl(icp->conn_expstatsn);
2205 	icp->conn_laststatsn = icp->conn_expstatsn;
2206 	iscsi_tx_pdu(icp, ISCSI_OP_NOOP_OUT, inohp,
2207 	    sizeof (iscsi_nop_out_hdr_t), icmdp);
2208 	return (rval);
2209 }
2210 
2211 
2212 /*
2213  * iscsi_tx_abort -
2214  *
2215  */
2216 static iscsi_status_t
2217 iscsi_tx_abort(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
2218 {
2219 	iscsi_status_t			rval	= ISCSI_STATUS_SUCCESS;
2220 	iscsi_conn_t			*icp	= NULL;
2221 	iscsi_scsi_task_mgt_hdr_t	*istmh;
2222 
2223 	ASSERT(isp != NULL);
2224 	ASSERT(icmdp != NULL);
2225 	icp = icmdp->cmd_conn;
2226 	ASSERT(icp != NULL);
2227 
2228 	istmh = kmem_zalloc(sizeof (iscsi_scsi_task_mgt_hdr_t), KM_SLEEP);
2229 	ASSERT(istmh != NULL);
2230 	mutex_enter(&isp->sess_cmdsn_mutex);
2231 	icmdp->cmd_sn	= isp->sess_cmdsn;
2232 	istmh->cmdsn	= htonl(isp->sess_cmdsn);
2233 	mutex_exit(&isp->sess_cmdsn_mutex);
2234 	istmh->expstatsn = htonl(icp->conn_expstatsn);
2235 	icp->conn_laststatsn = icp->conn_expstatsn;
2236 	istmh->itt	= icmdp->cmd_itt;
2237 	istmh->opcode	= ISCSI_OP_SCSI_TASK_MGT_MSG | ISCSI_OP_IMMEDIATE;
2238 	istmh->function	= ISCSI_FLAG_FINAL | ISCSI_TM_FUNC_ABORT_TASK;
2239 	ISCSI_LUN_BYTE_COPY(istmh->lun,
2240 	    icmdp->cmd_un.abort.icmdp->cmd_un.scsi.lun);
2241 	istmh->rtt	= icmdp->cmd_un.abort.icmdp->cmd_itt;
2242 	iscsi_tx_pdu(icp, ISCSI_OP_SCSI_TASK_MGT_MSG, istmh,
2243 	    sizeof (iscsi_scsi_task_mgt_hdr_t), icmdp);
2244 
2245 	return (rval);
2246 }
2247 
2248 
2249 /*
2250  * iscsi_tx_reset -
2251  *
2252  */
2253 static iscsi_status_t
2254 iscsi_tx_reset(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
2255 {
2256 	iscsi_status_t			rval	= ISCSI_STATUS_SUCCESS;
2257 	iscsi_conn_t			*icp	= NULL;
2258 	iscsi_scsi_task_mgt_hdr_t	*istmh;
2259 
2260 	ASSERT(isp != NULL);
2261 	ASSERT(icmdp != NULL);
2262 	icp = icmdp->cmd_conn;
2263 	ASSERT(icp != NULL);
2264 
2265 	istmh = kmem_zalloc(sizeof (iscsi_scsi_task_mgt_hdr_t), KM_SLEEP);
2266 	ASSERT(istmh != NULL);
2267 	istmh->opcode	= ISCSI_OP_SCSI_TASK_MGT_MSG | ISCSI_OP_IMMEDIATE;
2268 	mutex_enter(&isp->sess_cmdsn_mutex);
2269 	icmdp->cmd_sn	= isp->sess_cmdsn;
2270 	istmh->cmdsn	= htonl(isp->sess_cmdsn);
2271 	mutex_exit(&isp->sess_cmdsn_mutex);
2272 	istmh->expstatsn	= htonl(icp->conn_expstatsn);
2273 	istmh->itt	= icmdp->cmd_itt;
2274 
2275 	switch (icmdp->cmd_un.reset.level) {
2276 	case RESET_LUN:
2277 		istmh->function	= ISCSI_FLAG_FINAL |
2278 		    ISCSI_TM_FUNC_LOGICAL_UNIT_RESET;
2279 		ISCSI_LUN_BYTE_COPY(istmh->lun, icmdp->cmd_lun->lun_num);
2280 		break;
2281 	case RESET_TARGET:
2282 	case RESET_BUS:
2283 		istmh->function	= ISCSI_FLAG_FINAL |
2284 		    ISCSI_TM_FUNC_TARGET_WARM_RESET;
2285 		break;
2286 	default:
2287 		/* unsupported / unknown level */
2288 		ASSERT(FALSE);
2289 		break;
2290 	}
2291 
2292 	iscsi_tx_pdu(icp, ISCSI_OP_SCSI_TASK_MGT_MSG, istmh,
2293 	    sizeof (iscsi_scsi_task_mgt_hdr_t), icmdp);
2294 
2295 	return (rval);
2296 }
2297 
2298 
2299 /*
2300  * iscsi_tx_logout -
2301  *
2302  */
2303 static iscsi_status_t
2304 iscsi_tx_logout(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
2305 {
2306 	iscsi_status_t		rval	= ISCSI_STATUS_SUCCESS;
2307 	iscsi_conn_t		*icp	= NULL;
2308 	iscsi_logout_hdr_t	*ilh;
2309 
2310 	ASSERT(isp != NULL);
2311 	ASSERT(icmdp != NULL);
2312 	icp = icmdp->cmd_conn;
2313 	ASSERT(icp != NULL);
2314 
2315 	ilh = kmem_zalloc(sizeof (iscsi_logout_hdr_t), KM_SLEEP);
2316 	ilh->opcode	= ISCSI_OP_LOGOUT_CMD | ISCSI_OP_IMMEDIATE;
2317 	ilh->flags	= ISCSI_FLAG_FINAL | ISCSI_LOGOUT_REASON_CLOSE_SESSION;
2318 	ilh->itt		= icmdp->cmd_itt;
2319 	ilh->cid		= icp->conn_cid;
2320 	mutex_enter(&isp->sess_cmdsn_mutex);
2321 	icmdp->cmd_sn	= isp->sess_cmdsn;
2322 	ilh->cmdsn	= htonl(isp->sess_cmdsn);
2323 	mutex_exit(&isp->sess_cmdsn_mutex);
2324 	ilh->expstatsn	= htonl(icp->conn_expstatsn);
2325 	iscsi_tx_pdu(icp, ISCSI_OP_LOGOUT_CMD, ilh,
2326 	    sizeof (iscsi_logout_hdr_t), icmdp);
2327 
2328 	return (rval);
2329 }
2330 
2331 /*
2332  * iscsi_tx_text - setup iSCSI text request header and send PDU with
2333  * data given in the buffer attached to the command.  For a single
2334  * text request, the target may need to send its response in multiple
2335  * text response.  In this case, empty text requests are sent after
2336  * each received response to notify the target the initiator is ready
2337  * for more response.  For the initial request, the data_len field in
2338  * the text specific portion of a command is set to the amount of data
2339  * the initiator wants to send as part of the request. If additional
2340  * empty text requests are required for long responses, the data_len
2341  * field is set to 0 by the iscsi_handle_text function.
2342  */
2343 static iscsi_status_t
2344 iscsi_tx_text(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
2345 {
2346 	iscsi_status_t		rval	= ISCSI_STATUS_SUCCESS;
2347 	iscsi_conn_t		*icp	= NULL;
2348 	iscsi_text_hdr_t	*ith;
2349 
2350 	ASSERT(icmdp != NULL);
2351 	icp = icmdp->cmd_conn;
2352 	ASSERT(icp != NULL);
2353 
2354 	ith = kmem_zalloc(sizeof (iscsi_text_hdr_t), KM_SLEEP);
2355 	ASSERT(ith != NULL);
2356 	ith->flags	= ISCSI_FLAG_FINAL;
2357 	hton24(ith->dlength, icmdp->cmd_un.text.data_len);
2358 	ith->ttt		= icmdp->cmd_un.text.ttt;
2359 	iscsi_tx_init_hdr(isp, icp, (iscsi_text_hdr_t *)ith,
2360 	    ISCSI_OP_TEXT_CMD, icmdp);
2361 	bcopy(icmdp->cmd_un.text.lun, ith->rsvd4, sizeof (ith->rsvd4));
2362 
2363 	iscsi_tx_pdu(icp, ISCSI_OP_TEXT_CMD, ith, sizeof (iscsi_text_hdr_t),
2364 	    icmdp);
2365 
2366 	return (rval);
2367 }
2368 
2369 /*
2370  * +--------------------------------------------------------------------+
2371  * | End of protocol send routines					|
2372  * +--------------------------------------------------------------------+
2373  */
2374 
2375 /*
2376  * iscsi_handle_abort -
2377  *
2378  */
2379 void
2380 iscsi_handle_abort(void *arg)
2381 {
2382 	iscsi_sess_t	*isp		= NULL;
2383 	iscsi_cmd_t	*icmdp		= (iscsi_cmd_t *)arg;
2384 	iscsi_cmd_t	*new_icmdp;
2385 	iscsi_conn_t	*icp;
2386 
2387 	ASSERT(icmdp != NULL);
2388 	icp = icmdp->cmd_conn;
2389 	ASSERT(icp != NULL);
2390 	isp = icp->conn_sess;
2391 	ASSERT(isp != NULL);
2392 
2393 	/* there should only be one abort */
2394 	ASSERT(icmdp->cmd_un.scsi.abort_icmdp == NULL);
2395 
2396 	new_icmdp = iscsi_cmd_alloc(icp, KM_SLEEP);
2397 	new_icmdp->cmd_type		    = ISCSI_CMD_TYPE_ABORT;
2398 	new_icmdp->cmd_lun		    = icmdp->cmd_lun;
2399 	new_icmdp->cmd_un.abort.icmdp	    = icmdp;
2400 	new_icmdp->cmd_conn		    = icmdp->cmd_conn;
2401 	icmdp->cmd_un.scsi.abort_icmdp	    = new_icmdp;
2402 
2403 	/* pending queue mutex is already held by timeout_checks */
2404 	iscsi_cmd_state_machine(new_icmdp, ISCSI_CMD_EVENT_E1, isp);
2405 }
2406 
2407 /*
2408  * Callback from IDM indicating that the task has been suspended or aborted.
2409  */
2410 void
2411 iscsi_task_aborted(idm_task_t *idt, idm_status_t status)
2412 {
2413 	iscsi_cmd_t *icmdp = idt->idt_private;
2414 	iscsi_conn_t *icp = icmdp->cmd_conn;
2415 	iscsi_sess_t *isp = icp->conn_sess;
2416 
2417 	ASSERT(icmdp->cmd_conn != NULL);
2418 
2419 	switch (status) {
2420 	case IDM_STATUS_SUSPENDED:
2421 		/*
2422 		 * If the task is suspended, it may be aborted later,
2423 		 * so we can ignore this notification.
2424 		 */
2425 		break;
2426 
2427 	case IDM_STATUS_ABORTED:
2428 		mutex_enter(&icp->conn_queue_active.mutex);
2429 		iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E9, isp);
2430 		mutex_exit(&icp->conn_queue_active.mutex);
2431 		break;
2432 
2433 	default:
2434 		/*
2435 		 * Unexpected status.
2436 		 */
2437 		ASSERT(0);
2438 	}
2439 
2440 }
2441 
2442 /*
2443  * iscsi_handle_nop -
2444  *
2445  */
2446 static void
2447 iscsi_handle_nop(iscsi_conn_t *icp, uint32_t itt, uint32_t ttt)
2448 {
2449 	iscsi_sess_t	*isp	= NULL;
2450 	iscsi_cmd_t	*icmdp	= NULL;
2451 
2452 	ASSERT(icp != NULL);
2453 	isp = icp->conn_sess;
2454 	ASSERT(isp != NULL);
2455 
2456 	icmdp = iscsi_cmd_alloc(icp, KM_NOSLEEP);
2457 	if (icmdp == NULL) {
2458 		return;
2459 	}
2460 
2461 	icmdp->cmd_type		= ISCSI_CMD_TYPE_NOP;
2462 	icmdp->cmd_itt		= itt;
2463 	icmdp->cmd_ttt		= ttt;
2464 	icmdp->cmd_lun		= NULL;
2465 	icp->conn_nop_lbolt	= ddi_get_lbolt();
2466 
2467 	iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E1, isp);
2468 }
2469 
2470 /*
2471  * iscsi_handle_reset - send reset request to the target
2472  *
2473  */
2474 iscsi_status_t
2475 iscsi_handle_reset(iscsi_sess_t *isp, int level, iscsi_lun_t *ilp)
2476 {
2477 	iscsi_status_t	rval	= ISCSI_STATUS_SUCCESS;
2478 	iscsi_conn_t	*icp;
2479 	iscsi_cmd_t	icmd;
2480 
2481 	ASSERT(isp != NULL);
2482 
2483 	if (level == RESET_LUN) {
2484 		rw_enter(&isp->sess_lun_list_rwlock, RW_WRITER);
2485 		ASSERT(ilp != NULL);
2486 		if (ilp->lun_state & ISCSI_LUN_STATE_BUSY) {
2487 			rw_exit(&isp->sess_lun_list_rwlock);
2488 			return (ISCSI_STATUS_SUCCESS);
2489 		}
2490 		ilp->lun_state |= ISCSI_LUN_STATE_BUSY;
2491 		rw_exit(&isp->sess_lun_list_rwlock);
2492 	} else {
2493 		mutex_enter(&isp->sess_reset_mutex);
2494 		if (isp->sess_reset_in_progress == B_TRUE) {
2495 			/*
2496 			 * If the reset is in progress, it is unnecessary
2497 			 * to send reset to the target redunantly.
2498 			 */
2499 			mutex_exit(&isp->sess_reset_mutex);
2500 			return (ISCSI_STATUS_SUCCESS);
2501 		}
2502 		isp->sess_reset_in_progress = B_TRUE;
2503 		mutex_exit(&isp->sess_reset_mutex);
2504 	}
2505 
2506 	bzero(&icmd, sizeof (iscsi_cmd_t));
2507 	icmd.cmd_sig		= ISCSI_SIG_CMD;
2508 	icmd.cmd_state		= ISCSI_CMD_STATE_FREE;
2509 	icmd.cmd_type		= ISCSI_CMD_TYPE_RESET;
2510 	icmd.cmd_lun		= ilp;
2511 	icmd.cmd_un.reset.level	= level;
2512 	icmd.cmd_result		= ISCSI_STATUS_SUCCESS;
2513 	icmd.cmd_completed	= B_FALSE;
2514 	icmd.cmd_un.reset.response = SCSI_TCP_TM_RESP_COMPLETE;
2515 
2516 	mutex_init(&icmd.cmd_mutex, NULL, MUTEX_DRIVER, NULL);
2517 	cv_init(&icmd.cmd_completion, NULL, CV_DRIVER, NULL);
2518 	/*
2519 	 * If we received an IO and we are not in the
2520 	 * LOGGED_IN state we are in the process of
2521 	 * failing.  Just respond that we are BUSY.
2522 	 */
2523 	mutex_enter(&isp->sess_state_mutex);
2524 	if (!ISCSI_SESS_STATE_FULL_FEATURE(isp->sess_state)) {
2525 		/* We aren't connected to the target fake success */
2526 		mutex_exit(&isp->sess_state_mutex);
2527 
2528 		if (level == RESET_LUN) {
2529 			rw_enter(&isp->sess_lun_list_rwlock, RW_WRITER);
2530 			ilp->lun_state &= ~ISCSI_LUN_STATE_BUSY;
2531 			rw_exit(&isp->sess_lun_list_rwlock);
2532 		} else {
2533 			mutex_enter(&isp->sess_reset_mutex);
2534 			isp->sess_reset_in_progress = B_FALSE;
2535 			mutex_exit(&isp->sess_reset_mutex);
2536 		}
2537 
2538 		return (ISCSI_STATUS_SUCCESS);
2539 	}
2540 
2541 	mutex_enter(&isp->sess_queue_pending.mutex);
2542 	iscsi_cmd_state_machine(&icmd, ISCSI_CMD_EVENT_E1, isp);
2543 	mutex_exit(&isp->sess_queue_pending.mutex);
2544 	mutex_exit(&isp->sess_state_mutex);
2545 
2546 	/* stall until completed */
2547 	mutex_enter(&icmd.cmd_mutex);
2548 	while (icmd.cmd_completed == B_FALSE) {
2549 		cv_wait(&icmd.cmd_completion, &icmd.cmd_mutex);
2550 	}
2551 	mutex_exit(&icmd.cmd_mutex);
2552 
2553 	/* copy rval */
2554 	rval = icmd.cmd_result;
2555 
2556 	if (rval == ISCSI_STATUS_SUCCESS) {
2557 		/*
2558 		 * Reset was successful.  We need to flush
2559 		 * all active IOs.
2560 		 */
2561 		rw_enter(&isp->sess_conn_list_rwlock, RW_READER);
2562 		icp = isp->sess_conn_list;
2563 		while (icp != NULL) {
2564 			iscsi_cmd_t *t_icmdp = NULL;
2565 			iscsi_cmd_t *next_icmdp = NULL;
2566 
2567 			mutex_enter(&icp->conn_queue_active.mutex);
2568 			t_icmdp = icp->conn_queue_active.head;
2569 			while (t_icmdp != NULL) {
2570 				next_icmdp = t_icmdp->cmd_next;
2571 				mutex_enter(&t_icmdp->cmd_mutex);
2572 				if (!(t_icmdp->cmd_misc_flags &
2573 				    ISCSI_CMD_MISCFLAG_SENT)) {
2574 					/*
2575 					 * Although this command is in the
2576 					 * active queue, it has not been sent.
2577 					 * Skip it.
2578 					 */
2579 					mutex_exit(&t_icmdp->cmd_mutex);
2580 					t_icmdp = next_icmdp;
2581 					continue;
2582 				}
2583 				if (level == RESET_LUN) {
2584 					if (icmd.cmd_lun == NULL ||
2585 					    t_icmdp->cmd_lun == NULL ||
2586 					    (icmd.cmd_lun->lun_num !=
2587 					    t_icmdp->cmd_lun->lun_num)) {
2588 						mutex_exit(&t_icmdp->cmd_mutex);
2589 						t_icmdp = next_icmdp;
2590 						continue;
2591 					}
2592 				}
2593 
2594 				if (icmd.cmd_sn == t_icmdp->cmd_sn) {
2595 					/*
2596 					 * This command may be replied with
2597 					 * UA sense key later. So currently
2598 					 * it is not a suitable time to flush
2599 					 * it. Mark its flag with FLUSH. There
2600 					 * is no harm to keep it for a while.
2601 					 */
2602 					t_icmdp->cmd_misc_flags |=
2603 					    ISCSI_CMD_MISCFLAG_FLUSH;
2604 					if (t_icmdp->cmd_type ==
2605 					    ISCSI_CMD_TYPE_SCSI) {
2606 						t_icmdp->cmd_un.scsi.pkt_stat |=
2607 						    STAT_BUS_RESET;
2608 					}
2609 					mutex_exit(&t_icmdp->cmd_mutex);
2610 				} else if ((icmd.cmd_sn > t_icmdp->cmd_sn) ||
2611 				    ((t_icmdp->cmd_sn - icmd.cmd_sn) >
2612 				    ISCSI_CMD_SN_WRAP)) {
2613 					/*
2614 					 * This reset request must act on all
2615 					 * the commnds from the same session
2616 					 * having a CmdSN lower than the task
2617 					 * mangement CmdSN. So flush these
2618 					 * commands here.
2619 					 */
2620 					if (t_icmdp->cmd_type ==
2621 					    ISCSI_CMD_TYPE_SCSI) {
2622 						t_icmdp->cmd_un.scsi.pkt_stat |=
2623 						    STAT_BUS_RESET;
2624 					}
2625 					mutex_exit(&t_icmdp->cmd_mutex);
2626 					iscsi_cmd_state_machine(t_icmdp,
2627 					    ISCSI_CMD_EVENT_E7, isp);
2628 				} else {
2629 					mutex_exit(&t_icmdp->cmd_mutex);
2630 				}
2631 
2632 				t_icmdp = next_icmdp;
2633 			}
2634 
2635 			mutex_exit(&icp->conn_queue_active.mutex);
2636 			icp = icp->conn_next;
2637 		}
2638 		rw_exit(&isp->sess_conn_list_rwlock);
2639 	}
2640 
2641 	/* clean up */
2642 	cv_destroy(&icmd.cmd_completion);
2643 	mutex_destroy(&icmd.cmd_mutex);
2644 
2645 	if (level == RESET_LUN) {
2646 		rw_enter(&isp->sess_lun_list_rwlock, RW_WRITER);
2647 		ilp->lun_state &= ~ISCSI_LUN_STATE_BUSY;
2648 		rw_exit(&isp->sess_lun_list_rwlock);
2649 	} else {
2650 		mutex_enter(&isp->sess_reset_mutex);
2651 		isp->sess_reset_in_progress = B_FALSE;
2652 		mutex_exit(&isp->sess_reset_mutex);
2653 	}
2654 
2655 	return (rval);
2656 }
2657 
2658 /*
2659  * iscsi_lgoout_start - task handler for deferred logout
2660  */
2661 static void
2662 iscsi_logout_start(void *arg)
2663 {
2664 	iscsi_task_t		*itp = (iscsi_task_t *)arg;
2665 	iscsi_conn_t		*icp;
2666 
2667 	icp = (iscsi_conn_t *)itp->t_arg;
2668 
2669 	mutex_enter(&icp->conn_state_mutex);
2670 	(void) iscsi_handle_logout(icp);
2671 	mutex_exit(&icp->conn_state_mutex);
2672 }
2673 
2674 /*
2675  * iscsi_handle_logout - This function will issue a logout for
2676  * the session from a specific connection.
2677  */
2678 iscsi_status_t
2679 iscsi_handle_logout(iscsi_conn_t *icp)
2680 {
2681 	iscsi_sess_t	*isp;
2682 	idm_conn_t	*ic;
2683 	iscsi_cmd_t	*icmdp;
2684 	int		rval;
2685 
2686 	ASSERT(icp != NULL);
2687 	isp = icp->conn_sess;
2688 	ic = icp->conn_ic;
2689 	ASSERT(isp != NULL);
2690 	ASSERT(isp->sess_hba != NULL);
2691 	ASSERT(mutex_owned(&icp->conn_state_mutex));
2692 
2693 	/*
2694 	 * We may want to explicitly disconnect if something goes wrong so
2695 	 * grab a hold to ensure that the IDM connection context can't
2696 	 * disappear.
2697 	 */
2698 	idm_conn_hold(ic);
2699 
2700 	icmdp = iscsi_cmd_alloc(icp, KM_SLEEP);
2701 	ASSERT(icmdp != NULL);
2702 	icmdp->cmd_type		= ISCSI_CMD_TYPE_LOGOUT;
2703 	icmdp->cmd_result	= ISCSI_STATUS_SUCCESS;
2704 	icmdp->cmd_completed	= B_FALSE;
2705 
2706 	mutex_enter(&isp->sess_queue_pending.mutex);
2707 	iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E1, isp);
2708 	mutex_exit(&isp->sess_queue_pending.mutex);
2709 
2710 	/*
2711 	 * release connection state mutex to avoid a deadlock.  This
2712 	 * function is called from within the connection state
2713 	 * machine with the lock held.  When the logout response is
2714 	 * received another call to the connection state machine
2715 	 * occurs which causes the deadlock
2716 	 */
2717 	mutex_exit(&icp->conn_state_mutex);
2718 
2719 	/* stall until completed */
2720 	mutex_enter(&icmdp->cmd_mutex);
2721 	while (icmdp->cmd_completed == B_FALSE) {
2722 		cv_wait(&icmdp->cmd_completion, &icmdp->cmd_mutex);
2723 	}
2724 	mutex_exit(&icmdp->cmd_mutex);
2725 	mutex_enter(&icp->conn_state_mutex);
2726 
2727 	/* copy rval */
2728 	rval = icmdp->cmd_result;
2729 
2730 	/* clean up */
2731 	iscsi_cmd_free(icmdp);
2732 
2733 	if (rval != 0) {
2734 		/* If the logout failed then drop the connection */
2735 		idm_ini_conn_disconnect(icp->conn_ic);
2736 	}
2737 
2738 	/* stall until connection settles */
2739 	while ((icp->conn_state != ISCSI_CONN_STATE_FREE) &&
2740 	    (icp->conn_state != ISCSI_CONN_STATE_FAILED) &&
2741 	    (icp->conn_state != ISCSI_CONN_STATE_POLLING)) {
2742 		/* wait for transition */
2743 		cv_wait(&icp->conn_state_change, &icp->conn_state_mutex);
2744 	}
2745 
2746 	idm_conn_rele(ic);
2747 
2748 	/*
2749 	 * Return value reflects whether the logout command completed --
2750 	 * regardless of the return value the connection is closed and
2751 	 * ready for reconnection.
2752 	 */
2753 	return (rval);
2754 }
2755 
2756 
2757 /*
2758  * iscsi_handle_text - main control function for iSCSI text requests.  This
2759  * function handles allocating the command, sending initial text request, and
2760  * handling long response sequence.
2761  * If a data overflow condition occurs, iscsi_handle_text continues to
2762  * receive responses until the all data has been recieved.  This allows
2763  * the full data length to be returned to the caller.
2764  */
2765 iscsi_status_t
2766 iscsi_handle_text(iscsi_conn_t *icp, char *buf, uint32_t buf_len,
2767     uint32_t data_len, uint32_t *rx_data_len)
2768 {
2769 	iscsi_sess_t	*isp;
2770 	iscsi_cmd_t	*icmdp;
2771 	iscsi_status_t	rval	= ISCSI_STATUS_SUCCESS;
2772 
2773 	ASSERT(icp != NULL);
2774 	ASSERT(buf != NULL);
2775 	ASSERT(rx_data_len != NULL);
2776 
2777 	isp = icp->conn_sess;
2778 	ASSERT(isp != NULL);
2779 
2780 	/*
2781 	 * Ensure data for text request command is not greater
2782 	 * than the negotiated maximum receive data seqment length.
2783 	 *
2784 	 * Although iSCSI allows for long text requests (multiple
2785 	 * pdus), this function places a restriction on text
2786 	 * requests to ensure it is handled by a single PDU.
2787 	 */
2788 	if (data_len > icp->conn_params.max_xmit_data_seg_len) {
2789 		return (ISCSI_STATUS_CMD_FAILED);
2790 	}
2791 
2792 	icmdp = iscsi_cmd_alloc(icp, KM_SLEEP);
2793 	ASSERT(icmdp != NULL);
2794 
2795 	icmdp->cmd_type		= ISCSI_CMD_TYPE_TEXT;
2796 	icmdp->cmd_result	= ISCSI_STATUS_SUCCESS;
2797 	icmdp->cmd_misc_flags	&= ~ISCSI_CMD_MISCFLAG_FREE;
2798 	icmdp->cmd_completed	= B_FALSE;
2799 
2800 	icmdp->cmd_un.text.buf		= buf;
2801 	icmdp->cmd_un.text.buf_len	= buf_len;
2802 	icmdp->cmd_un.text.offset	= 0;
2803 	icmdp->cmd_un.text.data_len	= data_len;
2804 	icmdp->cmd_un.text.total_rx_len	= 0;
2805 	icmdp->cmd_un.text.ttt		= ISCSI_RSVD_TASK_TAG;
2806 	icmdp->cmd_un.text.stage	= ISCSI_CMD_TEXT_INITIAL_REQ;
2807 
2808 long_text_response:
2809 	mutex_enter(&isp->sess_state_mutex);
2810 	if (!ISCSI_SESS_STATE_FULL_FEATURE(isp->sess_state)) {
2811 		iscsi_cmd_free(icmdp);
2812 		mutex_exit(&isp->sess_state_mutex);
2813 		return (ISCSI_STATUS_NO_CONN_LOGGED_IN);
2814 	}
2815 
2816 	mutex_enter(&isp->sess_queue_pending.mutex);
2817 	iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E1, isp);
2818 	mutex_exit(&isp->sess_queue_pending.mutex);
2819 	mutex_exit(&isp->sess_state_mutex);
2820 
2821 	/* stall until completed */
2822 	mutex_enter(&icmdp->cmd_mutex);
2823 	while (icmdp->cmd_completed == B_FALSE) {
2824 		cv_wait(&icmdp->cmd_completion, &icmdp->cmd_mutex);
2825 	}
2826 	mutex_exit(&icmdp->cmd_mutex);
2827 
2828 	/*
2829 	 * check if error occured.  If data overflow occured, continue on
2830 	 * to ensure we get all data so that the full data length can be
2831 	 * returned to the user
2832 	 */
2833 	if ((icmdp->cmd_result != ISCSI_STATUS_SUCCESS) &&
2834 	    (icmdp->cmd_result != ISCSI_STATUS_DATA_OVERFLOW)) {
2835 		cmn_err(CE_NOTE, "iscsi: SendTarget discovery failed (%d)",
2836 		    icmdp->cmd_result);
2837 		rval = icmdp->cmd_result;
2838 		iscsi_cmd_free(icmdp);
2839 		return (rval);
2840 	}
2841 
2842 	/* check if this was a partial text PDU  */
2843 	if (icmdp->cmd_un.text.stage != ISCSI_CMD_TEXT_FINAL_RSP) {
2844 		/*
2845 		 * If a paritial text rexponse received, send an empty
2846 		 * text request.  This follows the behaviour specified
2847 		 * in RFC3720 regarding long text responses.
2848 		 */
2849 		icmdp->cmd_misc_flags		&= ~ISCSI_CMD_MISCFLAG_FREE;
2850 		icmdp->cmd_completed		= B_FALSE;
2851 		icmdp->cmd_un.text.data_len	= 0;
2852 		icmdp->cmd_un.text.stage	= ISCSI_CMD_TEXT_CONTINUATION;
2853 		goto long_text_response;
2854 	}
2855 
2856 	/*
2857 	 * set total received data length.  If data overflow this would be
2858 	 * amount of data that would have been received if buffer large
2859 	 * enough.
2860 	 */
2861 	*rx_data_len = icmdp->cmd_un.text.total_rx_len;
2862 
2863 	/* copy rval */
2864 	rval = icmdp->cmd_result;
2865 
2866 	/* clean up  */
2867 	iscsi_cmd_free(icmdp);
2868 
2869 	return (rval);
2870 }
2871 
2872 /*
2873  * iscsi_handle_passthru - This function is used to send a uscsi_cmd
2874  * to a specific target lun.  This routine is used for internal purposes
2875  * during enumeration and via the ISCSI_USCSICMD IOCTL.  We restrict
2876  * the CDBs that can be issued to a target/lun to INQUIRY, REPORT_LUNS,
2877  * and READ_CAPACITY for security purposes.
2878  *
2879  * The logic here is broken into three phases.
2880  * 1) Allocate and initialize a pkt/icmdp
2881  * 2) Send the pkt/icmdp
2882  * 3) cv_wait for completion
2883  */
2884 iscsi_status_t
2885 iscsi_handle_passthru(iscsi_sess_t *isp, uint16_t lun, struct uscsi_cmd *ucmdp)
2886 {
2887 	iscsi_status_t		rval		= ISCSI_STATUS_SUCCESS;
2888 	iscsi_cmd_t		*icmdp		= NULL;
2889 	struct scsi_pkt		*pkt		= NULL;
2890 	struct buf		*bp		= NULL;
2891 	struct scsi_arq_status  *arqstat	= NULL;
2892 	int			rqlen		= SENSE_LENGTH;
2893 
2894 	ASSERT(isp != NULL);
2895 	ASSERT(ucmdp != NULL);
2896 
2897 	/*
2898 	 * If the caller didn't provide a sense buffer we need
2899 	 * to allocation one to get the scsi status.
2900 	 */
2901 	if (ucmdp->uscsi_rqlen > SENSE_LENGTH) {
2902 		rqlen = ucmdp->uscsi_rqlen;
2903 	}
2904 
2905 	/*
2906 	 * Step 1. Setup structs - KM_SLEEP will always succeed
2907 	 */
2908 	bp = kmem_zalloc(sizeof (struct buf), KM_SLEEP);
2909 	ASSERT(bp != NULL);
2910 	pkt = kmem_zalloc(sizeof (struct scsi_pkt), KM_SLEEP);
2911 	ASSERT(pkt != NULL);
2912 	icmdp = iscsi_cmd_alloc(NULL, KM_SLEEP);
2913 	ASSERT(icmdp != NULL);
2914 
2915 	/* setup bp structure */
2916 	bp->b_flags		= B_READ;
2917 	bp->b_bcount		= ucmdp->uscsi_buflen;
2918 	bp->b_un.b_addr		= ucmdp->uscsi_bufaddr;
2919 
2920 	/* setup scsi_pkt structure */
2921 	pkt->pkt_ha_private	= icmdp;
2922 	pkt->pkt_scbp		= kmem_zalloc(rqlen, KM_SLEEP);
2923 	pkt->pkt_cdbp		= kmem_zalloc(ucmdp->uscsi_cdblen, KM_SLEEP);
2924 	/* callback routine for passthru, will wake cv_wait */
2925 	pkt->pkt_comp		= iscsi_handle_passthru_callback;
2926 	pkt->pkt_time		= ucmdp->uscsi_timeout;
2927 
2928 	/* setup iscsi_cmd structure */
2929 	icmdp->cmd_lun			= NULL;
2930 	icmdp->cmd_type			= ISCSI_CMD_TYPE_SCSI;
2931 	icmdp->cmd_un.scsi.lun		= lun;
2932 	icmdp->cmd_un.scsi.pkt		= pkt;
2933 	icmdp->cmd_un.scsi.bp		= bp;
2934 	bcopy(ucmdp->uscsi_cdb, pkt->pkt_cdbp, ucmdp->uscsi_cdblen);
2935 	icmdp->cmd_un.scsi.cmdlen	= ucmdp->uscsi_cdblen;
2936 	icmdp->cmd_un.scsi.statuslen	= rqlen;
2937 	icmdp->cmd_crc_error_seen	= B_FALSE;
2938 	icmdp->cmd_completed		= B_FALSE;
2939 	icmdp->cmd_result		= ISCSI_STATUS_SUCCESS;
2940 
2941 	/*
2942 	 * Step 2. Push IO onto pending queue.  If we aren't in
2943 	 * FULL_FEATURE we need to fail the IO.
2944 	 */
2945 	mutex_enter(&isp->sess_state_mutex);
2946 	if (!ISCSI_SESS_STATE_FULL_FEATURE(isp->sess_state)) {
2947 		mutex_exit(&isp->sess_state_mutex);
2948 
2949 		iscsi_cmd_free(icmdp);
2950 		kmem_free(pkt->pkt_cdbp, ucmdp->uscsi_cdblen);
2951 		kmem_free(pkt->pkt_scbp, rqlen);
2952 		kmem_free(pkt, sizeof (struct scsi_pkt));
2953 		kmem_free(bp, sizeof (struct buf));
2954 
2955 		return (ISCSI_STATUS_CMD_FAILED);
2956 	}
2957 
2958 	mutex_enter(&isp->sess_queue_pending.mutex);
2959 	iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E1, isp);
2960 	mutex_exit(&isp->sess_queue_pending.mutex);
2961 	mutex_exit(&isp->sess_state_mutex);
2962 
2963 	/*
2964 	 * Step 3. Wait on cv_wait for completion routine
2965 	 */
2966 	mutex_enter(&icmdp->cmd_mutex);
2967 	while (icmdp->cmd_completed == B_FALSE) {
2968 		cv_wait(&icmdp->cmd_completion, &icmdp->cmd_mutex);
2969 	}
2970 	mutex_exit(&icmdp->cmd_mutex);
2971 
2972 	/* copy rval */
2973 	rval = icmdp->cmd_result;
2974 
2975 	ucmdp->uscsi_resid = pkt->pkt_resid;
2976 
2977 	/* update scsi status */
2978 	arqstat = (struct scsi_arq_status *)pkt->pkt_scbp;
2979 	ucmdp->uscsi_status = ((char *)&arqstat->sts_status)[0];
2980 
2981 	/* copy request sense buffers if caller gave space */
2982 	if ((ucmdp->uscsi_rqlen > 0) &&
2983 	    (ucmdp->uscsi_rqbuf != NULL)) {
2984 		bcopy(arqstat, ucmdp->uscsi_rqbuf,
2985 		    MIN(sizeof (struct scsi_arq_status), rqlen));
2986 	}
2987 
2988 	/* clean up */
2989 	iscsi_cmd_free(icmdp);
2990 	kmem_free(pkt->pkt_cdbp, ucmdp->uscsi_cdblen);
2991 	kmem_free(pkt->pkt_scbp, rqlen);
2992 	kmem_free(pkt, sizeof (struct scsi_pkt));
2993 	kmem_free(bp, sizeof (struct buf));
2994 
2995 	return (rval);
2996 }
2997 
2998 
2999 /*
3000  * iscsi_handle_passthru_callback -
3001  *
3002  */
3003 static void
3004 iscsi_handle_passthru_callback(struct scsi_pkt *pkt)
3005 {
3006 	iscsi_cmd_t		*icmdp  = NULL;
3007 
3008 	ASSERT(pkt != NULL);
3009 	icmdp = (iscsi_cmd_t *)pkt->pkt_ha_private;
3010 	ASSERT(icmdp != NULL);
3011 
3012 	mutex_enter(&icmdp->cmd_mutex);
3013 	icmdp->cmd_completed    = B_TRUE;
3014 	icmdp->cmd_result	= ISCSI_STATUS_SUCCESS;
3015 	cv_broadcast(&icmdp->cmd_completion);
3016 	mutex_exit(&icmdp->cmd_mutex);
3017 
3018 }
3019 
3020 /*
3021  * IDM callbacks
3022  */
3023 void
3024 iscsi_build_hdr(idm_task_t *idm_task, idm_pdu_t *pdu, uint8_t opcode)
3025 {
3026 	iscsi_cmd_t *icmdp = idm_task->idt_private;
3027 	iscsi_conn_t *icp = icmdp->cmd_conn;
3028 	iscsi_data_hdr_t *ihp = (iscsi_data_hdr_t *)pdu->isp_hdr;
3029 
3030 	mutex_enter(&icmdp->cmd_mutex);
3031 	if (opcode == ISCSI_OP_SCSI_DATA) {
3032 		uint32_t	data_sn;
3033 		uint32_t	lun;
3034 		icmdp = idm_task->idt_private;
3035 		icp = icmdp->cmd_conn;
3036 		ihp->opcode	= opcode;
3037 		ihp->itt	= icmdp->cmd_itt;
3038 		ihp->ttt	= idm_task->idt_r2t_ttt;
3039 		ihp->expstatsn	= htonl(icp->conn_expstatsn);
3040 		icp->conn_laststatsn = icp->conn_expstatsn;
3041 		data_sn = ntohl(ihp->datasn);
3042 		data_sn++;
3043 		lun = icmdp->cmd_un.scsi.lun;
3044 		ISCSI_LUN_BYTE_COPY(ihp->lun, lun);
3045 		/* CRM: upate_flow_control */
3046 		ISCSI_IO_LOG(CE_NOTE, "DEBUG: iscsi_build_hdr"
3047 		    "(ISCSI_OP_SCSI_DATA): task: %p icp: %p ic: %p itt: %x "
3048 		    "exp: %d data_sn: %d", (void *)idm_task, (void *)icp,
3049 		    (void *)icp->conn_ic, ihp->itt, icp->conn_expstatsn,
3050 		    data_sn);
3051 	} else {
3052 		cmn_err(CE_WARN, "iscsi_build_hdr: unprocessed build "
3053 		    "header opcode: %x", opcode);
3054 	}
3055 	mutex_exit(&icmdp->cmd_mutex);
3056 }
3057 
3058 static void
3059 iscsi_process_rsp_status(iscsi_sess_t *isp, iscsi_conn_t *icp,
3060     idm_status_t status)
3061 {
3062 	switch (status) {
3063 	case IDM_STATUS_SUCCESS:
3064 		if ((isp->sess_state == ISCSI_SESS_STATE_IN_FLUSH) &&
3065 		    (icp->conn_queue_active.count == 0)) {
3066 			iscsi_drop_conn_cleanup(icp);
3067 		}
3068 		break;
3069 	case IDM_STATUS_PROTOCOL_ERROR:
3070 		KSTAT_INC_CONN_ERR_PROTOCOL(icp);
3071 		iscsi_drop_conn_cleanup(icp);
3072 		break;
3073 	default:
3074 		break;
3075 	}
3076 }
3077 
3078 static void
3079 iscsi_drop_conn_cleanup(iscsi_conn_t *icp) {
3080 	mutex_enter(&icp->conn_state_mutex);
3081 	idm_ini_conn_disconnect(icp->conn_ic);
3082 	mutex_exit(&icp->conn_state_mutex);
3083 }
3084 
3085 void
3086 iscsi_rx_error_pdu(idm_conn_t *ic, idm_pdu_t *pdu, idm_status_t status)
3087 {
3088 	iscsi_conn_t *icp = (iscsi_conn_t *)ic->ic_handle;
3089 	iscsi_sess_t *isp;
3090 
3091 	ASSERT(icp != NULL);
3092 	isp = icp->conn_sess;
3093 	ASSERT(isp != NULL);
3094 	iscsi_process_rsp_status(isp, icp, status);
3095 	idm_pdu_complete(pdu, status);
3096 }
3097 
3098 void
3099 iscsi_rx_misc_pdu(idm_conn_t *ic, idm_pdu_t *pdu)
3100 {
3101 	iscsi_conn_t 		*icp;
3102 	iscsi_hdr_t		*ihp	= (iscsi_hdr_t *)pdu->isp_hdr;
3103 	iscsi_sess_t		*isp;
3104 	idm_status_t		status;
3105 
3106 	icp = ic->ic_handle;
3107 	isp = icp->conn_sess;
3108 	isp->sess_rx_lbolt = icp->conn_rx_lbolt = ddi_get_lbolt();
3109 	switch (ihp->opcode & ISCSI_OPCODE_MASK) {
3110 	case ISCSI_OP_LOGIN_RSP:
3111 		status = iscsi_rx_process_login_pdu(ic, pdu);
3112 		idm_pdu_complete(pdu, status);
3113 		break;
3114 	case ISCSI_OP_LOGOUT_RSP:
3115 		status = iscsi_rx_process_logout_rsp(ic, pdu);
3116 		idm_pdu_complete(pdu, status);
3117 		break;
3118 	case ISCSI_OP_REJECT_MSG:
3119 		status = iscsi_rx_process_reject_rsp(ic, pdu);
3120 		break;
3121 	case ISCSI_OP_SCSI_TASK_MGT_RSP:
3122 		status = iscsi_rx_process_task_mgt_rsp(ic, pdu);
3123 		idm_pdu_complete(pdu, status);
3124 		break;
3125 	case ISCSI_OP_NOOP_IN:
3126 		status = iscsi_rx_process_nop(ic, pdu);
3127 		idm_pdu_complete(pdu, status);
3128 		break;
3129 	case ISCSI_OP_ASYNC_EVENT:
3130 		status = iscsi_rx_process_async_rsp(ic, pdu);
3131 		break;
3132 	case ISCSI_OP_TEXT_RSP:
3133 		status = iscsi_rx_process_text_rsp(ic, pdu);
3134 		idm_pdu_complete(pdu, status);
3135 		break;
3136 	default:
3137 		cmn_err(CE_WARN, "iscsi connection(%u) protocol error "
3138 		    "- received misc unsupported opcode 0x%02x",
3139 		    icp->conn_oid, ihp->opcode);
3140 		status = IDM_STATUS_PROTOCOL_ERROR;
3141 		break;
3142 	}
3143 	iscsi_process_rsp_status(isp, icp, status);
3144 }
3145 
3146 /*
3147  * +--------------------------------------------------------------------+
3148  * | Beginning of completion routines					|
3149  * +--------------------------------------------------------------------+
3150  */
3151 
3152 /*
3153  * iscsi_ic_thread -
3154  */
3155 void
3156 iscsi_ic_thread(iscsi_thread_t *thread, void *arg)
3157 {
3158 	iscsi_sess_t	*isp = (iscsi_sess_t *)arg;
3159 	int		ret;
3160 	iscsi_queue_t	q;
3161 	iscsi_cmd_t	*icmdp;
3162 	iscsi_cmd_t	*next_icmdp;
3163 
3164 	ASSERT(isp != NULL);
3165 	ASSERT(thread != NULL);
3166 	ASSERT(thread->signature == SIG_ISCSI_THREAD);
3167 
3168 	for (;;) {
3169 
3170 		/*
3171 		 * We wait till iodone or somebody else wakes us up.
3172 		 */
3173 		ret = iscsi_thread_wait(thread, -1);
3174 
3175 		/*
3176 		 * The value should never be negative since we never timeout.
3177 		 */
3178 		ASSERT(ret >= 0);
3179 
3180 		q.count = 0;
3181 		q.head  = NULL;
3182 		q.tail  = NULL;
3183 		mutex_enter(&isp->sess_queue_completion.mutex);
3184 		icmdp = isp->sess_queue_completion.head;
3185 		while (icmdp != NULL) {
3186 			next_icmdp = icmdp->cmd_next;
3187 			mutex_enter(&icmdp->cmd_mutex);
3188 			/*
3189 			 * check if the associated r2t/abort has finished
3190 			 * yet.  If not, don't complete the command.
3191 			 */
3192 			if ((icmdp->cmd_un.scsi.r2t_icmdp == NULL) &&
3193 			    (icmdp->cmd_un.scsi.abort_icmdp == NULL)) {
3194 				mutex_exit(&icmdp->cmd_mutex);
3195 				(void) iscsi_dequeue_cmd(&isp->
3196 				    sess_queue_completion.head,
3197 				    &isp->sess_queue_completion.tail,
3198 				    icmdp);
3199 				--isp->sess_queue_completion.count;
3200 				iscsi_enqueue_cmd_head(&q.head,
3201 				    &q.tail, icmdp);
3202 			} else {
3203 				mutex_exit(&icmdp->cmd_mutex);
3204 			}
3205 			icmdp = next_icmdp;
3206 		}
3207 		mutex_exit(&isp->sess_queue_completion.mutex);
3208 		icmdp = q.head;
3209 		while (icmdp != NULL) {
3210 			next_icmdp = icmdp->cmd_next;
3211 			iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E8, isp);
3212 			icmdp = next_icmdp;
3213 		}
3214 
3215 		if (ret > 0)
3216 			/* Somebody woke us up to work */
3217 			continue;
3218 		else
3219 			/*
3220 			 * Somebody woke us up to kill ourselves. We will
3221 			 * make sure, however that the completion queue is
3222 			 * empty before leaving.  After we've done that it
3223 			 * is the originator of the signal that has to make
3224 			 * sure no other SCSI command is posted.
3225 			 */
3226 			break;
3227 	}
3228 
3229 }
3230 
3231 /*
3232  * iscsi_iodone -
3233  *
3234  */
3235 void
3236 iscsi_iodone(iscsi_sess_t *isp, iscsi_cmd_t *icmdp)
3237 {
3238 	struct scsi_pkt		*pkt	= NULL;
3239 	struct buf		*bp	= icmdp->cmd_un.scsi.bp;
3240 
3241 	ASSERT(isp != NULL);
3242 	ASSERT(icmdp != NULL);
3243 	pkt = icmdp->cmd_un.scsi.pkt;
3244 	ASSERT(pkt != NULL);
3245 
3246 	ASSERT(icmdp->cmd_un.scsi.abort_icmdp == NULL);
3247 	ASSERT(icmdp->cmd_un.scsi.r2t_icmdp == NULL);
3248 	if (pkt->pkt_reason == CMD_CMPLT) {
3249 		if (bp) {
3250 			if (bp->b_flags & B_READ) {
3251 				KSTAT_SESS_RX_IO_DONE(isp, bp->b_bcount);
3252 			} else {
3253 				KSTAT_SESS_TX_IO_DONE(isp, bp->b_bcount);
3254 			}
3255 		}
3256 	}
3257 
3258 	if (pkt->pkt_flags & FLAG_NOINTR) {
3259 		cv_broadcast(&icmdp->cmd_completion);
3260 		mutex_exit(&icmdp->cmd_mutex);
3261 	} else {
3262 		/*
3263 		 * Release mutex.  As soon as callback is
3264 		 * issued the caller may destroy the command.
3265 		 */
3266 		mutex_exit(&icmdp->cmd_mutex);
3267 		/*
3268 		 * We can't just directly call the pk_comp routine.  In
3269 		 * many error cases the target driver will use the calling
3270 		 * thread to re-drive error handling (reset, retries...)
3271 		 * back into the hba driver (iscsi).  If the target redrives
3272 		 * a reset back into the iscsi driver off this thead we have
3273 		 * a chance of deadlocking. So instead use the io completion
3274 		 * thread.
3275 		 */
3276 		(*icmdp->cmd_un.scsi.pkt->pkt_comp)(icmdp->cmd_un.scsi.pkt);
3277 	}
3278 }
3279 
3280 /*
3281  * +--------------------------------------------------------------------+
3282  * | End of completion routines						|
3283  * +--------------------------------------------------------------------+
3284  */
3285 
3286 /*
3287  * +--------------------------------------------------------------------+
3288  * | Beginning of watchdog routines					|
3289  * +--------------------------------------------------------------------+
3290  */
3291 
3292 /*
3293  * iscsi_watchdog_thread -
3294  *
3295  */
3296 void
3297 iscsi_wd_thread(iscsi_thread_t *thread, void *arg)
3298 {
3299 	iscsi_sess_t	*isp = (iscsi_sess_t *)arg;
3300 	int		rc = 1;
3301 
3302 	ASSERT(isp != NULL);
3303 
3304 	while (rc != NULL) {
3305 
3306 		iscsi_timeout_checks(isp);
3307 		iscsi_nop_checks(isp);
3308 
3309 		rc = iscsi_thread_wait(thread, SEC_TO_TICK(1));
3310 	}
3311 }
3312 
3313 /*
3314  * iscsi_timeout_checks -
3315  *
3316  */
3317 static void
3318 iscsi_timeout_checks(iscsi_sess_t *isp)
3319 {
3320 	clock_t		now = ddi_get_lbolt();
3321 	iscsi_conn_t	*icp;
3322 	iscsi_cmd_t	*icmdp, *nicmdp;
3323 
3324 	ASSERT(isp != NULL);
3325 
3326 	/* PENDING */
3327 	mutex_enter(&isp->sess_state_mutex);
3328 	mutex_enter(&isp->sess_queue_pending.mutex);
3329 	for (icmdp = isp->sess_queue_pending.head;
3330 	    icmdp; icmdp = nicmdp) {
3331 		nicmdp = icmdp->cmd_next;
3332 
3333 		/* Skip entries with no timeout */
3334 		if (icmdp->cmd_lbolt_timeout == 0)
3335 			continue;
3336 
3337 		/*
3338 		 * Skip pending queue entries for cmd_type values that depend
3339 		 * on having an open cmdsn window for successfull transition
3340 		 * from pending to the active (i.e. ones that depend on
3341 		 * sess_cmdsn .vs. sess_maxcmdsn). For them, the timer starts
3342 		 * when they are successfully moved to the active queue by
3343 		 * iscsi_cmd_state_pending() code.
3344 		 */
3345 		/*
3346 		 * If the cmd is stuck, at least give it a chance
3347 		 * to timeout
3348 		 */
3349 		if (((icmdp->cmd_type == ISCSI_CMD_TYPE_SCSI) ||
3350 		    (icmdp->cmd_type == ISCSI_CMD_TYPE_TEXT)) &&
3351 		    !(icmdp->cmd_misc_flags & ISCSI_CMD_MISCFLAG_STUCK))
3352 			continue;
3353 
3354 		/* Skip if timeout still in the future */
3355 		if (now <= icmdp->cmd_lbolt_timeout)
3356 			continue;
3357 
3358 		/* timeout */
3359 		iscsi_cmd_state_machine(icmdp, ISCSI_CMD_EVENT_E6, isp);
3360 	}
3361 	mutex_exit(&isp->sess_queue_pending.mutex);
3362 	mutex_exit(&isp->sess_state_mutex);
3363 
3364 	rw_enter(&isp->sess_conn_list_rwlock, RW_READER);
3365 	icp = isp->sess_conn_list;
3366 	while (icp != NULL) {
3367 
3368 		icp->conn_timeout = B_FALSE;
3369 		/* ACTIVE */
3370 		mutex_enter(&icp->conn_state_mutex);
3371 		mutex_enter(&isp->sess_queue_pending.mutex);
3372 		mutex_enter(&icp->conn_queue_active.mutex);
3373 		for (icmdp = icp->conn_queue_active.head;
3374 		    icmdp; icmdp = nicmdp) {
3375 			nicmdp = icmdp->cmd_next;
3376 
3377 			if (iscsi_nop_timeout_checks(icmdp) == B_TRUE) {
3378 				icp->conn_timeout = B_TRUE;
3379 			}
3380 
3381 			/* Skip entries with no timeout */
3382 			if (icmdp->cmd_lbolt_timeout == 0)
3383 				continue;
3384 
3385 			/*
3386 			 * Skip if command is not active or not needed
3387 			 * to flush.
3388 			 */
3389 			if (icmdp->cmd_state != ISCSI_CMD_STATE_ACTIVE &&
3390 			    !(icmdp->cmd_misc_flags & ISCSI_CMD_MISCFLAG_FLUSH))
3391 				continue;
3392 
3393 			/* Skip if timeout still in the future */
3394 			if (now <= icmdp->cmd_lbolt_timeout)
3395 				continue;
3396 
3397 			if (icmdp->cmd_misc_flags & ISCSI_CMD_MISCFLAG_FLUSH) {
3398 				/*
3399 				 * This command is left during target reset,
3400 				 * we can flush it now.
3401 				 */
3402 				iscsi_cmd_state_machine(icmdp,
3403 				    ISCSI_CMD_EVENT_E7, isp);
3404 			} else if (icmdp->cmd_state == ISCSI_CMD_STATE_ACTIVE) {
3405 				/* timeout */
3406 				iscsi_cmd_state_machine(icmdp,
3407 				    ISCSI_CMD_EVENT_E6, isp);
3408 			}
3409 
3410 		}
3411 		mutex_exit(&icp->conn_queue_active.mutex);
3412 		mutex_exit(&isp->sess_queue_pending.mutex);
3413 		mutex_exit(&icp->conn_state_mutex);
3414 
3415 		icp = icp->conn_next;
3416 	}
3417 
3418 	icp = isp->sess_conn_list;
3419 	while (icp != NULL) {
3420 		if (icp->conn_timeout == B_TRUE) {
3421 			/* timeout on this connect detected */
3422 			idm_ini_conn_disconnect(icp->conn_ic);
3423 			icp->conn_timeout = B_FALSE;
3424 		}
3425 		icp = icp->conn_next;
3426 	}
3427 	rw_exit(&isp->sess_conn_list_rwlock);
3428 }
3429 
3430 /*
3431  * iscsi_nop_checks - sends a NOP on idle connections
3432  *
3433  * This function walks the connections on a session and
3434  * issues NOPs on those connections that are in FULL
3435  * FEATURE mode and have not received data for the
3436  * time period specified by iscsi_nop_delay (global).
3437  */
3438 static void
3439 iscsi_nop_checks(iscsi_sess_t *isp)
3440 {
3441 	iscsi_conn_t	*icp;
3442 
3443 	ASSERT(isp != NULL);
3444 
3445 	if (isp->sess_type == ISCSI_SESS_TYPE_DISCOVERY) {
3446 		return;
3447 	}
3448 
3449 	rw_enter(&isp->sess_conn_list_rwlock, RW_READER);
3450 	icp = isp->sess_conn_act;
3451 	if (icp != NULL) {
3452 
3453 		mutex_enter(&icp->conn_state_mutex);
3454 		if ((ISCSI_CONN_STATE_FULL_FEATURE(icp->conn_state)) &&
3455 		    (ddi_get_lbolt() > isp->sess_conn_act->conn_rx_lbolt +
3456 		    SEC_TO_TICK(iscsi_nop_delay)) && (ddi_get_lbolt() >
3457 		    isp->sess_conn_act->conn_nop_lbolt +
3458 		    SEC_TO_TICK(iscsi_nop_delay))) {
3459 
3460 			/*
3461 			 * We haven't received anything from the
3462 			 * target is a defined period of time,
3463 			 * send NOP to see if the target is alive.
3464 			 */
3465 			mutex_enter(&isp->sess_queue_pending.mutex);
3466 			iscsi_handle_nop(isp->sess_conn_act,
3467 			    0, ISCSI_RSVD_TASK_TAG);
3468 			mutex_exit(&isp->sess_queue_pending.mutex);
3469 		}
3470 		mutex_exit(&icp->conn_state_mutex);
3471 
3472 		icp = icp->conn_next;
3473 	}
3474 	rw_exit(&isp->sess_conn_list_rwlock);
3475 }
3476 
3477 static boolean_t
3478 iscsi_nop_timeout_checks(iscsi_cmd_t *icmdp)
3479 {
3480 	if (icmdp->cmd_type == ISCSI_CMD_TYPE_NOP) {
3481 		if ((ddi_get_lbolt() - icmdp->cmd_lbolt_active) >
3482 		    SEC_TO_TICK(ISCSI_CONN_TIEMOUT_DETECT)) {
3483 			return (B_TRUE);
3484 		} else {
3485 			return (B_FALSE);
3486 		}
3487 	}
3488 	return (B_FALSE);
3489 }
3490 /*
3491  * +--------------------------------------------------------------------+
3492  * | End of wd routines						|
3493  * +--------------------------------------------------------------------+
3494  */
3495 
3496 /*
3497  * iscsi_flush_cmd_after_reset - flush commands after reset
3498  *
3499  * Here we will flush all the commands in the same connection whose cmdsn is
3500  * less than the one received with the Unit Attention.
3501  */
3502 static void
3503 iscsi_flush_cmd_after_reset(uint32_t cmd_sn, uint16_t lun_num,
3504     iscsi_conn_t *icp)
3505 {
3506 	iscsi_cmd_t	*t_icmdp    = NULL;
3507 	iscsi_cmd_t	*next_icmdp = NULL;
3508 
3509 	ASSERT(icp != NULL);
3510 
3511 	t_icmdp = icp->conn_queue_active.head;
3512 	while (t_icmdp != NULL) {
3513 		next_icmdp = t_icmdp->cmd_next;
3514 		mutex_enter(&t_icmdp->cmd_mutex);
3515 		/*
3516 		 * We will flush the commands whose cmdsn is less than the one
3517 		 * got Unit Attention.
3518 		 * Here we will check for wrap by subtracting and compare to
3519 		 * 1/2 of a 32 bit number, if greater then we wrapped.
3520 		 */
3521 		if ((t_icmdp->cmd_misc_flags & ISCSI_CMD_MISCFLAG_SENT) &&
3522 		    ((cmd_sn > t_icmdp->cmd_sn) ||
3523 		    ((t_icmdp->cmd_sn - cmd_sn) >
3524 		    ISCSI_CMD_SN_WRAP))) {
3525 			if (t_icmdp->cmd_lun != NULL &&
3526 			    t_icmdp->cmd_lun->lun_num == lun_num) {
3527 				t_icmdp->cmd_misc_flags |=
3528 				    ISCSI_CMD_MISCFLAG_FLUSH;
3529 				if (t_icmdp->cmd_type == ISCSI_CMD_TYPE_SCSI) {
3530 					t_icmdp->cmd_un.scsi.pkt_stat |=
3531 					    STAT_BUS_RESET;
3532 				}
3533 			}
3534 		}
3535 		mutex_exit(&t_icmdp->cmd_mutex);
3536 		t_icmdp = next_icmdp;
3537 	}
3538 }
3539 
3540 /*
3541  * iscsi_decode_sense - decode the sense data in the cmd response
3542  *
3543  * Here we only care about Unit Attention with 0x29.
3544  */
3545 static boolean_t
3546 iscsi_decode_sense(uint8_t *sense_data)
3547 {
3548 	uint8_t	sense_key   = 0;
3549 	uint8_t	asc	    = 0;
3550 	boolean_t affect    = B_FALSE;
3551 
3552 	ASSERT(sense_data != NULL);
3553 
3554 	sense_key = scsi_sense_key(sense_data);
3555 	switch (sense_key) {
3556 		case KEY_UNIT_ATTENTION:
3557 			asc = scsi_sense_asc(sense_data);
3558 			switch (asc) {
3559 				case ISCSI_SCSI_RESET_SENSE_CODE:
3560 					/*
3561 					 * POWER ON, RESET, OR BUS_DEVICE RESET
3562 					 * OCCURRED
3563 					 */
3564 					affect = B_TRUE;
3565 					break;
3566 				default:
3567 					/*
3568 					 * Currently we don't care
3569 					 * about other sense key.
3570 					 */
3571 					break;
3572 			}
3573 			break;
3574 		default:
3575 			/*
3576 			 * Currently we don't care
3577 			 * about other sense key.
3578 			 */
3579 			break;
3580 	}
3581 	return (affect);
3582 }
3583