xref: /spdk/lib/iscsi/iscsi.c (revision c4d9daeb7bf491bc0eb6e8d417b75d44773cb009)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (C) 2008-2012 Daisuke Aoyama <aoyama@peach.ne.jp>.
5  *   Copyright (c) Intel Corporation.
6  *   All rights reserved.
7  *
8  *   Redistribution and use in source and binary forms, with or without
9  *   modification, are permitted provided that the following conditions
10  *   are met:
11  *
12  *     * Redistributions of source code must retain the above copyright
13  *       notice, this list of conditions and the following disclaimer.
14  *     * Redistributions in binary form must reproduce the above copyright
15  *       notice, this list of conditions and the following disclaimer in
16  *       the documentation and/or other materials provided with the
17  *       distribution.
18  *     * Neither the name of Intel Corporation nor the names of its
19  *       contributors may be used to endorse or promote products derived
20  *       from this software without specific prior written permission.
21  *
22  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include "spdk/stdinc.h"
36 
37 #include "spdk/base64.h"
38 #include "spdk/crc32.h"
39 #include "spdk/endian.h"
40 #include "spdk/env.h"
41 #include "spdk/likely.h"
42 #include "spdk/trace.h"
43 #include "spdk/string.h"
44 #include "spdk/queue.h"
45 #include "spdk/net.h"
46 
47 #include "iscsi/md5.h"
48 #include "iscsi/iscsi.h"
49 #include "iscsi/param.h"
50 #include "iscsi/tgt_node.h"
51 #include "iscsi/task.h"
52 #include "iscsi/conn.h"
53 #include "spdk/scsi.h"
54 #include "spdk/bdev.h"
55 #include "iscsi/portal_grp.h"
56 #include "iscsi/acceptor.h"
57 
58 #include "spdk_internal/log.h"
59 
60 #define MAX_TMPBUF 1024
61 
62 #define SPDK_CRC32C_INITIAL    0xffffffffUL
63 #define SPDK_CRC32C_XOR        0xffffffffUL
64 
65 #ifdef __FreeBSD__
66 #define HAVE_SRANDOMDEV 1
67 #define HAVE_ARC4RANDOM 1
68 #endif
69 
70 struct spdk_iscsi_globals g_spdk_iscsi = {
71 	.mutex = PTHREAD_MUTEX_INITIALIZER,
72 	.portal_head = TAILQ_HEAD_INITIALIZER(g_spdk_iscsi.portal_head),
73 	.pg_head = TAILQ_HEAD_INITIALIZER(g_spdk_iscsi.pg_head),
74 	.ig_head = TAILQ_HEAD_INITIALIZER(g_spdk_iscsi.ig_head),
75 	.target_head = TAILQ_HEAD_INITIALIZER(g_spdk_iscsi.target_head),
76 	.auth_group_head = TAILQ_HEAD_INITIALIZER(g_spdk_iscsi.auth_group_head),
77 };
78 
79 /* random value generation */
80 static void gen_random(uint8_t *buf, size_t len);
81 #ifndef HAVE_SRANDOMDEV
82 static void srandomdev(void);
83 #endif /* HAVE_SRANDOMDEV */
84 #ifndef HAVE_ARC4RANDOM
85 /* static uint32_t arc4random(void); */
86 #endif /* HAVE_ARC4RANDOM */
87 
88 static int add_transfer_task(struct spdk_iscsi_conn *conn,
89 			     struct spdk_iscsi_task *task);
90 
91 static int iscsi_send_r2t(struct spdk_iscsi_conn *conn,
92 			  struct spdk_iscsi_task *task, int offset,
93 			  int len, uint32_t transfer_tag, uint32_t *R2TSN);
94 static int iscsi_send_r2t_recovery(struct spdk_iscsi_conn *conn,
95 				   struct spdk_iscsi_task *r2t_task, uint32_t r2t_sn,
96 				   bool send_new_r2tsn);
97 
98 static int create_iscsi_sess(struct spdk_iscsi_conn *conn,
99 			     struct spdk_iscsi_tgt_node *target, enum session_type session_type);
100 static int append_iscsi_sess(struct spdk_iscsi_conn *conn,
101 			     const char *initiator_port_name, uint16_t tsih, uint16_t cid);
102 
103 static void remove_acked_pdu(struct spdk_iscsi_conn *conn, uint32_t ExpStatSN);
104 
105 static int iscsi_reject(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu,
106 			int reason);
107 
108 #define DMIN32(A,B) ((uint32_t) ((uint32_t)(A) > (uint32_t)(B) ? (uint32_t)(B) : (uint32_t)(A)))
109 #define DMIN64(A,B) ((uint64_t) ((A) > (B) ? (B) : (A)))
110 
111 #define MATCH_DIGEST_WORD(BUF, CRC32C) \
112 	(    ((((uint32_t) *((uint8_t *)(BUF)+0)) << 0)		\
113 	    | (((uint32_t) *((uint8_t *)(BUF)+1)) << 8)		\
114 	    | (((uint32_t) *((uint8_t *)(BUF)+2)) << 16)	\
115 	    | (((uint32_t) *((uint8_t *)(BUF)+3)) << 24))	\
116 	    == (CRC32C))
117 
118 #if 0
119 static int
120 match_digest_word(const uint8_t *buf, uint32_t crc32c)
121 {
122 	uint32_t l;
123 
124 	l = (buf[0] & 0xffU) << 0;
125 	l |= (buf[1] & 0xffU) << 8;
126 	l |= (buf[2] & 0xffU) << 16;
127 	l |= (buf[3] & 0xffU) << 24;
128 	return (l == crc32c);
129 }
130 
131 static uint8_t *
132 make_digest_word(uint8_t *buf, size_t len, uint32_t crc32c)
133 {
134 	if (len < ISCSI_DIGEST_LEN) {
135 		return NULL;
136 	}
137 
138 	buf[0] = (crc32c >> 0) & 0xffU;
139 	buf[1] = (crc32c >> 8) & 0xffU;
140 	buf[2] = (crc32c >> 16) & 0xffU;
141 	buf[3] = (crc32c >> 24) & 0xffU;
142 	return buf;
143 }
144 #endif
145 
146 #ifndef HAVE_SRANDOMDEV
147 static void
148 srandomdev(void)
149 {
150 	unsigned long seed;
151 	time_t now;
152 	pid_t pid;
153 
154 	pid = getpid();
155 	now = time(NULL);
156 	seed = pid ^ now;
157 	srandom(seed);
158 }
159 #endif /* HAVE_SRANDOMDEV */
160 
161 #ifndef HAVE_ARC4RANDOM
162 static int g_arc4random_initialized = 0;
163 
164 static uint32_t
165 arc4random(void)
166 {
167 	uint32_t r;
168 	uint32_t r1, r2;
169 
170 	if (!g_arc4random_initialized) {
171 		srandomdev();
172 		g_arc4random_initialized = 1;
173 	}
174 	r1 = (uint32_t)(random() & 0xffff);
175 	r2 = (uint32_t)(random() & 0xffff);
176 	r = (r1 << 16) | r2;
177 	return r;
178 }
179 #endif /* HAVE_ARC4RANDOM */
180 
181 static void
182 gen_random(uint8_t *buf, size_t len)
183 {
184 #ifdef USE_RANDOM
185 	long l;
186 	size_t idx;
187 
188 	srandomdev();
189 	for (idx = 0; idx < len; idx++) {
190 		l = random();
191 		buf[idx] = (uint8_t) l;
192 	}
193 #else
194 	uint32_t r;
195 	size_t idx;
196 
197 	for (idx = 0; idx < len; idx++) {
198 		r = arc4random();
199 		buf[idx] = (uint8_t) r;
200 	}
201 #endif /* USE_RANDOM */
202 }
203 
204 static uint64_t
205 iscsi_get_isid(const uint8_t isid[6])
206 {
207 	return (uint64_t)isid[0] << 40 |
208 	       (uint64_t)isid[1] << 32 |
209 	       (uint64_t)isid[2] << 24 |
210 	       (uint64_t)isid[3] << 16 |
211 	       (uint64_t)isid[4] << 8 |
212 	       (uint64_t)isid[5];
213 }
214 
215 static int
216 bin2hex(char *buf, size_t len, const uint8_t *data, size_t data_len)
217 {
218 	const char *digits = "0123456789ABCDEF";
219 	size_t total = 0;
220 	size_t idx;
221 
222 	if (len < 3) {
223 		return -1;
224 	}
225 	buf[total] = '0';
226 	total++;
227 	buf[total] = 'x';
228 	total++;
229 	buf[total] = '\0';
230 
231 	for (idx = 0; idx < data_len; idx++) {
232 		if (total + 3 > len) {
233 			buf[total] = '\0';
234 			return - 1;
235 		}
236 		buf[total] = digits[(data[idx] >> 4) & 0x0fU];
237 		total++;
238 		buf[total] = digits[data[idx] & 0x0fU];
239 		total++;
240 	}
241 	buf[total] = '\0';
242 	return total;
243 }
244 
245 static int
246 hex2bin(uint8_t *data, size_t data_len, const char *str)
247 {
248 	const char *digits = "0123456789ABCDEF";
249 	const char *dp;
250 	const char *p;
251 	size_t total = 0;
252 	int n0, n1;
253 
254 	p = str;
255 	if (p[0] != '0' && (p[1] != 'x' && p[1] != 'X')) {
256 		return -1;
257 	}
258 	p += 2;
259 
260 	while (p[0] != '\0' && p[1] != '\0') {
261 		if (total >= data_len) {
262 			return -1;
263 		}
264 		dp = strchr(digits, toupper((int) p[0]));
265 		if (dp == NULL) {
266 			return -1;
267 		}
268 		n0 = (int)(dp - digits);
269 		dp = strchr(digits, toupper((int) p[1]));
270 		if (dp == NULL) {
271 			return -1;
272 		}
273 		n1 = (int)(dp - digits);
274 
275 		data[total] = (uint8_t)(((n0 & 0x0fU) << 4) | (n1 & 0x0fU));
276 		total++;
277 		p += 2;
278 	}
279 	return total;
280 }
281 
282 uint32_t
283 spdk_iscsi_pdu_calc_header_digest(struct spdk_iscsi_pdu *pdu)
284 {
285 	uint32_t crc32c;
286 	uint32_t ahs_len_bytes = pdu->bhs.total_ahs_len * 4;
287 
288 	crc32c = SPDK_CRC32C_INITIAL;
289 	crc32c = spdk_crc32c_update(&pdu->bhs, ISCSI_BHS_LEN, crc32c);
290 
291 	if (ahs_len_bytes) {
292 		crc32c = spdk_crc32c_update(pdu->ahs, ahs_len_bytes, crc32c);
293 	}
294 
295 	/* BHS and AHS are always 4-byte multiples in length, so no padding is necessary. */
296 	crc32c = crc32c ^ SPDK_CRC32C_XOR;
297 	return crc32c;
298 }
299 
300 uint32_t
301 spdk_iscsi_pdu_calc_data_digest(struct spdk_iscsi_pdu *pdu)
302 {
303 	uint32_t data_len = DGET24(pdu->bhs.data_segment_len);
304 	uint32_t crc32c;
305 	uint32_t mod;
306 
307 	crc32c = SPDK_CRC32C_INITIAL;
308 	crc32c = spdk_crc32c_update(pdu->data, data_len, crc32c);
309 
310 	mod = data_len % ISCSI_ALIGNMENT;
311 	if (mod != 0) {
312 		uint32_t pad_length = ISCSI_ALIGNMENT - mod;
313 		uint8_t pad[3] = {0, 0, 0};
314 
315 		assert(pad_length > 0);
316 		assert(pad_length <= sizeof(pad));
317 		crc32c = spdk_crc32c_update(pad, pad_length, crc32c);
318 	}
319 
320 	crc32c = crc32c ^ SPDK_CRC32C_XOR;
321 	return crc32c;
322 }
323 
324 static bool
325 iscsi_check_data_segment_length(struct spdk_iscsi_conn *conn,
326 				struct spdk_iscsi_pdu *pdu, int data_len)
327 {
328 	int max_segment_len;
329 
330 	/*
331 	 * Determine the maximum segment length expected for this PDU.
332 	 *  This will be used to make sure the initiator did not send
333 	 *  us too much immediate data.
334 	 *
335 	 * This value is specified separately by the initiator and target,
336 	 *  and not negotiated.  So we can use the #define safely here,
337 	 *  since the value is not dependent on the initiator's maximum
338 	 *  segment lengths (FirstBurstLength/MaxRecvDataSegmentLength),
339 	 *  and SPDK currently does not allow configuration of these values
340 	 *  at runtime.
341 	 */
342 	if (conn->sess == NULL) {
343 		/*
344 		 * If the connection does not yet have a session, then
345 		 *  login is not complete and we use the 8KB default
346 		 *  FirstBurstLength as our maximum data segment length
347 		 *  value.
348 		 */
349 		max_segment_len = SPDK_ISCSI_FIRST_BURST_LENGTH;
350 	} else if (pdu->bhs.opcode == ISCSI_OP_SCSI_DATAOUT ||
351 		   pdu->bhs.opcode == ISCSI_OP_NOPOUT) {
352 		max_segment_len = SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH;
353 	} else {
354 		max_segment_len = spdk_get_max_immediate_data_size();
355 	}
356 	if (data_len <= max_segment_len) {
357 		return true;
358 	} else {
359 		SPDK_ERRLOG("Data(%d) > MaxSegment(%d)\n", data_len, max_segment_len);
360 		return false;
361 	}
362 }
363 
364 static int
365 iscsi_conn_read_data_segment(struct spdk_iscsi_conn *conn,
366 			     struct spdk_iscsi_pdu *pdu,
367 			     uint32_t segment_len)
368 {
369 	struct spdk_dif_ctx dif_ctx;
370 	struct iovec buf_iov, iovs[32];
371 	int rc, _rc;
372 
373 	if (spdk_likely(!spdk_iscsi_get_dif_ctx(conn, pdu, &dif_ctx))) {
374 		return spdk_iscsi_conn_read_data(conn,
375 						 segment_len - pdu->data_valid_bytes,
376 						 pdu->data_buf + pdu->data_valid_bytes);
377 	} else {
378 		pdu->dif_insert_or_strip = true;
379 		buf_iov.iov_base = pdu->data_buf;
380 		buf_iov.iov_len = pdu->data_buf_len;
381 		rc = spdk_dif_set_md_interleave_iovs(iovs, 32, &buf_iov, 1,
382 						     pdu->data_valid_bytes, segment_len, NULL,
383 						     &dif_ctx);
384 		if (rc > 0) {
385 			rc = spdk_iscsi_conn_readv_data(conn, iovs, rc);
386 			if (rc > 0) {
387 				_rc = spdk_dif_generate_stream(&buf_iov, 1,
388 							       pdu->data_valid_bytes, rc,
389 							       &dif_ctx);
390 				if (_rc != 0) {
391 					SPDK_ERRLOG("DIF generate failed\n");
392 					rc = _rc;
393 				}
394 			}
395 		} else {
396 			SPDK_ERRLOG("Setup iovs for interleaved metadata failed\n");
397 		}
398 		return rc;
399 	}
400 }
401 
402 int
403 spdk_iscsi_read_pdu(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu **_pdu)
404 {
405 	struct spdk_iscsi_pdu *pdu;
406 	struct spdk_mempool *pool;
407 	uint32_t crc32c;
408 	int ahs_len;
409 	int data_len;
410 	int rc;
411 
412 	if (conn->pdu_in_progress == NULL) {
413 		conn->pdu_in_progress = spdk_get_pdu();
414 		if (conn->pdu_in_progress == NULL) {
415 			return SPDK_ISCSI_CONNECTION_FATAL;
416 		}
417 	}
418 
419 	pdu = conn->pdu_in_progress;
420 
421 	if (pdu->bhs_valid_bytes < ISCSI_BHS_LEN) {
422 		rc = spdk_iscsi_conn_read_data(conn,
423 					       ISCSI_BHS_LEN - pdu->bhs_valid_bytes,
424 					       (uint8_t *)&pdu->bhs + pdu->bhs_valid_bytes);
425 		if (rc < 0) {
426 			*_pdu = NULL;
427 			spdk_put_pdu(pdu);
428 			conn->pdu_in_progress = NULL;
429 			return rc;
430 		}
431 		pdu->bhs_valid_bytes += rc;
432 		if (pdu->bhs_valid_bytes < ISCSI_BHS_LEN) {
433 			*_pdu = NULL;
434 			return SPDK_SUCCESS;
435 		}
436 	}
437 
438 	data_len = ISCSI_ALIGN(DGET24(pdu->bhs.data_segment_len));
439 
440 	/* AHS */
441 	ahs_len = pdu->bhs.total_ahs_len * 4;
442 	assert(ahs_len <= ISCSI_AHS_LEN);
443 	if (pdu->ahs_valid_bytes < ahs_len) {
444 		rc = spdk_iscsi_conn_read_data(conn,
445 					       ahs_len - pdu->ahs_valid_bytes,
446 					       pdu->ahs + pdu->ahs_valid_bytes);
447 		if (rc < 0) {
448 			*_pdu = NULL;
449 			spdk_put_pdu(pdu);
450 			conn->pdu_in_progress = NULL;
451 			return rc;
452 		}
453 
454 		pdu->ahs_valid_bytes += rc;
455 		if (pdu->ahs_valid_bytes < ahs_len) {
456 			*_pdu = NULL;
457 			return SPDK_SUCCESS;
458 		}
459 	}
460 
461 	/* Header Digest */
462 	if (conn->header_digest &&
463 	    pdu->hdigest_valid_bytes < ISCSI_DIGEST_LEN) {
464 		rc = spdk_iscsi_conn_read_data(conn,
465 					       ISCSI_DIGEST_LEN - pdu->hdigest_valid_bytes,
466 					       pdu->header_digest + pdu->hdigest_valid_bytes);
467 		if (rc < 0) {
468 			*_pdu = NULL;
469 			spdk_put_pdu(pdu);
470 			conn->pdu_in_progress = NULL;
471 			return rc;
472 		}
473 
474 		pdu->hdigest_valid_bytes += rc;
475 		if (pdu->hdigest_valid_bytes < ISCSI_DIGEST_LEN) {
476 			*_pdu = NULL;
477 			return SPDK_SUCCESS;
478 		}
479 	}
480 
481 	/* copy the actual data into local buffer */
482 	if (pdu->data_valid_bytes < data_len) {
483 		if (pdu->data_buf == NULL) {
484 			if (data_len <= spdk_get_max_immediate_data_size()) {
485 				pool = g_spdk_iscsi.pdu_immediate_data_pool;
486 				pdu->data_buf_len = SPDK_BDEV_BUF_SIZE_WITH_MD(spdk_get_max_immediate_data_size());
487 			} else if (data_len <= SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH) {
488 				pool = g_spdk_iscsi.pdu_data_out_pool;
489 				pdu->data_buf_len = SPDK_BDEV_BUF_SIZE_WITH_MD(SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH);
490 			} else {
491 				SPDK_ERRLOG("Data(%d) > MaxSegment(%d)\n",
492 					    data_len, SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH);
493 				*_pdu = NULL;
494 				spdk_put_pdu(pdu);
495 				conn->pdu_in_progress = NULL;
496 				return SPDK_ISCSI_CONNECTION_FATAL;
497 			}
498 			pdu->mobj = spdk_mempool_get(pool);
499 			if (pdu->mobj == NULL) {
500 				*_pdu = NULL;
501 				return SPDK_SUCCESS;
502 			}
503 			pdu->data_buf = pdu->mobj->buf;
504 		}
505 
506 		rc = iscsi_conn_read_data_segment(conn, pdu, data_len);
507 		if (rc < 0) {
508 			*_pdu = NULL;
509 			spdk_put_pdu(pdu);
510 			conn->pdu_in_progress = NULL;
511 			return rc;
512 		}
513 
514 		pdu->data_valid_bytes += rc;
515 		if (pdu->data_valid_bytes < data_len) {
516 			*_pdu = NULL;
517 			return SPDK_SUCCESS;
518 		}
519 	}
520 
521 	/* copy out the data digest */
522 	if (conn->data_digest && data_len != 0 &&
523 	    pdu->ddigest_valid_bytes < ISCSI_DIGEST_LEN) {
524 		rc = spdk_iscsi_conn_read_data(conn,
525 					       ISCSI_DIGEST_LEN - pdu->ddigest_valid_bytes,
526 					       pdu->data_digest + pdu->ddigest_valid_bytes);
527 		if (rc < 0) {
528 			*_pdu = NULL;
529 			spdk_put_pdu(pdu);
530 			conn->pdu_in_progress = NULL;
531 			return rc;
532 		}
533 
534 		pdu->ddigest_valid_bytes += rc;
535 		if (pdu->ddigest_valid_bytes < ISCSI_DIGEST_LEN) {
536 			*_pdu = NULL;
537 			return SPDK_SUCCESS;
538 		}
539 	}
540 
541 	/* All data for this PDU has now been read from the socket. */
542 	conn->pdu_in_progress = NULL;
543 
544 	spdk_trace_record(TRACE_ISCSI_READ_PDU, conn->id, pdu->data_valid_bytes,
545 			  (uintptr_t)pdu, pdu->bhs.opcode);
546 
547 	/* Data Segment */
548 	if (data_len != 0) {
549 		if (!iscsi_check_data_segment_length(conn, pdu, data_len)) {
550 			rc = iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
551 			spdk_put_pdu(pdu);
552 
553 			/*
554 			 * If spdk_iscsi_reject() was not able to reject the PDU,
555 			 * treat it as a fatal connection error.  Otherwise,
556 			 * return SUCCESS here so that the caller will continue
557 			 * to attempt to read PDUs.
558 			 */
559 			rc = (rc < 0) ? SPDK_ISCSI_CONNECTION_FATAL : SPDK_SUCCESS;
560 			return rc;
561 		}
562 
563 		pdu->data = pdu->data_buf;
564 		pdu->data_from_mempool = true;
565 		pdu->data_segment_len = data_len;
566 	}
567 
568 	/* check digest */
569 	if (conn->header_digest) {
570 		crc32c = spdk_iscsi_pdu_calc_header_digest(pdu);
571 		rc = MATCH_DIGEST_WORD(pdu->header_digest, crc32c);
572 		if (rc == 0) {
573 			SPDK_ERRLOG("header digest error (%s)\n", conn->initiator_name);
574 			spdk_put_pdu(pdu);
575 			return SPDK_ISCSI_CONNECTION_FATAL;
576 		}
577 	}
578 	if (conn->data_digest && data_len != 0) {
579 		crc32c = spdk_iscsi_pdu_calc_data_digest(pdu);
580 		rc = MATCH_DIGEST_WORD(pdu->data_digest, crc32c);
581 		if (rc == 0) {
582 			SPDK_ERRLOG("data digest error (%s)\n", conn->initiator_name);
583 			spdk_put_pdu(pdu);
584 			return SPDK_ISCSI_CONNECTION_FATAL;
585 		}
586 	}
587 
588 	*_pdu = pdu;
589 	return 1;
590 }
591 
592 struct _iov_ctx {
593 	struct iovec	*iov;
594 	int		num_iovs;
595 	uint32_t	iov_offset;
596 	int		iovcnt;
597 	uint32_t	mapped_len;
598 };
599 
600 static inline void
601 _iov_ctx_init(struct _iov_ctx *ctx, struct iovec *iovs, int num_iovs,
602 	      uint32_t iov_offset)
603 {
604 	ctx->iov = iovs;
605 	ctx->num_iovs = num_iovs;
606 	ctx->iov_offset = iov_offset;
607 	ctx->iovcnt = 0;
608 	ctx->mapped_len = 0;
609 }
610 
611 static inline bool
612 _iov_ctx_set_iov(struct _iov_ctx *ctx, uint8_t *data, uint32_t data_len)
613 {
614 	if (ctx->iov_offset >= data_len) {
615 		ctx->iov_offset -= data_len;
616 	} else {
617 		ctx->iov->iov_base = data + ctx->iov_offset;
618 		ctx->iov->iov_len = data_len - ctx->iov_offset;
619 		ctx->mapped_len += data_len - ctx->iov_offset;
620 		ctx->iov_offset = 0;
621 		ctx->iov++;
622 		ctx->iovcnt++;
623 		if (ctx->iovcnt == ctx->num_iovs) {
624 			return false;
625 		}
626 	}
627 
628 	return true;
629 }
630 
631 /* Build iovec array to leave metadata space for every data block
632  * when reading data segment from socket.
633  */
634 static inline bool
635 _iov_ctx_set_md_interleave_iov(struct _iov_ctx *ctx,
636 			       void *buf, uint32_t buf_len, uint32_t data_len,
637 			       struct spdk_dif_ctx *dif_ctx)
638 {
639 	int rc;
640 	uint32_t mapped_len = 0;
641 	struct iovec buf_iov;
642 
643 	if (ctx->iov_offset >= data_len) {
644 		ctx->iov_offset -= buf_len;
645 	} else {
646 		buf_iov.iov_base = buf;
647 		buf_iov.iov_len = buf_len;
648 		rc = spdk_dif_set_md_interleave_iovs(ctx->iov, ctx->num_iovs - ctx->iovcnt,
649 						     &buf_iov, 1,
650 						     ctx->iov_offset, data_len, &mapped_len,
651 						     dif_ctx);
652 		if (rc < 0) {
653 			SPDK_ERRLOG("Failed to setup iovs for DIF strip\n");
654 			return false;
655 		}
656 
657 		ctx->mapped_len += mapped_len;
658 		ctx->iov_offset = 0;
659 		ctx->iovcnt += rc;
660 
661 		if (ctx->iovcnt == ctx->num_iovs) {
662 			return false;
663 		}
664 	}
665 
666 	return true;
667 }
668 
669 int
670 spdk_iscsi_build_iovs(struct spdk_iscsi_conn *conn, struct iovec *iovs, int num_iovs,
671 		      struct spdk_iscsi_pdu *pdu, uint32_t *_mapped_length)
672 {
673 	struct _iov_ctx ctx;
674 	int enable_digest;
675 	uint32_t total_ahs_len;
676 	uint32_t data_len;
677 
678 	if (num_iovs == 0) {
679 		return 0;
680 	}
681 
682 	total_ahs_len = pdu->bhs.total_ahs_len;
683 	data_len = DGET24(pdu->bhs.data_segment_len);
684 	data_len = ISCSI_ALIGN(data_len);
685 
686 	enable_digest = 1;
687 	if (pdu->bhs.opcode == ISCSI_OP_LOGIN_RSP) {
688 		/* this PDU should be sent without digest */
689 		enable_digest = 0;
690 	}
691 
692 	_iov_ctx_init(&ctx, iovs, num_iovs, pdu->writev_offset);
693 
694 	/* BHS */
695 	if (!_iov_ctx_set_iov(&ctx, (uint8_t *)&pdu->bhs, ISCSI_BHS_LEN)) {
696 		goto end;
697 	}
698 	/* AHS */
699 	if (total_ahs_len > 0) {
700 		if (!_iov_ctx_set_iov(&ctx, pdu->ahs, 4 * total_ahs_len)) {
701 			goto end;
702 		}
703 	}
704 
705 	/* Header Digest */
706 	if (enable_digest && conn->header_digest) {
707 		if (!_iov_ctx_set_iov(&ctx, pdu->header_digest, ISCSI_DIGEST_LEN)) {
708 			goto end;
709 		}
710 	}
711 
712 	/* Data Segment */
713 	if (data_len > 0) {
714 		if (!pdu->dif_insert_or_strip) {
715 			if (!_iov_ctx_set_iov(&ctx, pdu->data, data_len)) {
716 				goto end;
717 			}
718 		} else {
719 			if (!_iov_ctx_set_md_interleave_iov(&ctx, pdu->data, pdu->data_buf_len,
720 							    data_len, &pdu->dif_ctx)) {
721 				goto end;
722 			}
723 		}
724 	}
725 
726 	/* Data Digest */
727 	if (enable_digest && conn->data_digest && data_len != 0) {
728 		_iov_ctx_set_iov(&ctx, pdu->data_digest, ISCSI_DIGEST_LEN);
729 	}
730 
731 end:
732 	if (_mapped_length != NULL) {
733 		*_mapped_length = ctx.mapped_len;
734 	}
735 
736 	return ctx.iovcnt;
737 }
738 
739 static int
740 iscsi_append_text(struct spdk_iscsi_conn *conn __attribute__((__unused__)),
741 		  const char *key, const char *val, uint8_t *data,
742 		  int alloc_len, int data_len)
743 {
744 	int total;
745 	int len;
746 
747 	total = data_len;
748 	if (alloc_len < 1) {
749 		return 0;
750 	}
751 	if (total > alloc_len) {
752 		total = alloc_len;
753 		data[total - 1] = '\0';
754 		return total;
755 	}
756 
757 	if (alloc_len - total < 1) {
758 		SPDK_ERRLOG("data space small %d\n", alloc_len);
759 		return total;
760 	}
761 	len = snprintf((char *) data + total, alloc_len - total, "%s=%s", key, val);
762 	total += len + 1;
763 
764 	return total;
765 }
766 
767 static int
768 iscsi_append_param(struct spdk_iscsi_conn *conn, const char *key,
769 		   uint8_t *data, int alloc_len, int data_len)
770 {
771 	struct iscsi_param *param;
772 	int rc;
773 
774 	param = spdk_iscsi_param_find(conn->params, key);
775 	if (param == NULL) {
776 		param = spdk_iscsi_param_find(conn->sess->params, key);
777 		if (param == NULL) {
778 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "no key %.64s\n", key);
779 			return data_len;
780 		}
781 	}
782 	rc = iscsi_append_text(conn, param->key, param->val, data,
783 			       alloc_len, data_len);
784 	return rc;
785 }
786 
787 static int
788 iscsi_get_authinfo(struct spdk_iscsi_conn *conn, const char *authuser)
789 {
790 	int ag_tag;
791 	int rc;
792 
793 	if (conn->sess->target != NULL) {
794 		ag_tag = conn->sess->target->chap_group;
795 	} else {
796 		ag_tag = -1;
797 	}
798 	if (ag_tag < 0) {
799 		ag_tag = g_spdk_iscsi.chap_group;
800 	}
801 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "ag_tag=%d\n", ag_tag);
802 
803 	rc = spdk_iscsi_chap_get_authinfo(&conn->auth, authuser, ag_tag);
804 	if (rc < 0) {
805 		SPDK_ERRLOG("chap_get_authinfo() failed\n");
806 		return -1;
807 	}
808 	return 0;
809 }
810 
811 static int
812 iscsi_auth_params(struct spdk_iscsi_conn *conn,
813 		  struct iscsi_param *params, const char *method, uint8_t *data,
814 		  int alloc_len, int data_len)
815 {
816 	char *in_val;
817 	char *in_next;
818 	char *new_val;
819 	const char *algorithm;
820 	const char *name;
821 	const char *response;
822 	const char *identifier;
823 	const char *challenge;
824 	int total;
825 	int rc;
826 
827 	if (conn == NULL || params == NULL || method == NULL) {
828 		return -1;
829 	}
830 	if (strcasecmp(method, "CHAP") == 0) {
831 		/* method OK */
832 	} else {
833 		SPDK_ERRLOG("unsupported AuthMethod %.64s\n", method);
834 		return -1;
835 	}
836 
837 	total = data_len;
838 	if (alloc_len < 1) {
839 		return 0;
840 	}
841 	if (total > alloc_len) {
842 		total = alloc_len;
843 		data[total - 1] = '\0';
844 		return total;
845 	}
846 
847 	/* for temporary store */
848 	in_val = malloc(ISCSI_TEXT_MAX_VAL_LEN + 1);
849 	if (!in_val) {
850 		SPDK_ERRLOG("malloc() failed for temporary store\n");
851 		return -ENOMEM;
852 	}
853 
854 	/* CHAP method (RFC1994) */
855 	if ((algorithm = spdk_iscsi_param_get_val(params, "CHAP_A")) != NULL) {
856 		if (conn->auth.chap_phase != ISCSI_CHAP_PHASE_WAIT_A) {
857 			SPDK_ERRLOG("CHAP sequence error\n");
858 			goto error_return;
859 		}
860 
861 		/* CHAP_A is LIST type */
862 		snprintf(in_val, ISCSI_TEXT_MAX_VAL_LEN + 1, "%s", algorithm);
863 		in_next = in_val;
864 		while ((new_val = spdk_strsepq(&in_next, ",")) != NULL) {
865 			if (strcasecmp(new_val, "5") == 0) {
866 				/* CHAP with MD5 */
867 				break;
868 			}
869 		}
870 		if (new_val == NULL) {
871 			snprintf(in_val, ISCSI_TEXT_MAX_VAL_LEN + 1, "%s", "Reject");
872 			new_val = in_val;
873 			iscsi_append_text(conn, "CHAP_A", new_val,
874 					  data, alloc_len, total);
875 			goto error_return;
876 		}
877 		/* selected algorithm is 5 (MD5) */
878 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "got CHAP_A=%s\n", new_val);
879 		total = iscsi_append_text(conn, "CHAP_A", new_val,
880 					  data, alloc_len, total);
881 
882 		/* Identifier is one octet */
883 		gen_random(conn->auth.chap_id, 1);
884 		snprintf(in_val, ISCSI_TEXT_MAX_VAL_LEN, "%d",
885 			 (int) conn->auth.chap_id[0]);
886 		total = iscsi_append_text(conn, "CHAP_I", in_val,
887 					  data, alloc_len, total);
888 
889 		/* Challenge Value is a variable stream of octets */
890 		/* (binary length MUST not exceed 1024 bytes) */
891 		conn->auth.chap_challenge_len = ISCSI_CHAP_CHALLENGE_LEN;
892 		gen_random(conn->auth.chap_challenge, conn->auth.chap_challenge_len);
893 		bin2hex(in_val, ISCSI_TEXT_MAX_VAL_LEN,
894 			conn->auth.chap_challenge, conn->auth.chap_challenge_len);
895 		total = iscsi_append_text(conn, "CHAP_C", in_val,
896 					  data, alloc_len, total);
897 
898 		conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_NR;
899 	} else if ((name = spdk_iscsi_param_get_val(params, "CHAP_N")) != NULL) {
900 		uint8_t resmd5[SPDK_MD5DIGEST_LEN];
901 		uint8_t tgtmd5[SPDK_MD5DIGEST_LEN];
902 		struct spdk_md5ctx md5ctx;
903 		size_t decoded_len = 0;
904 
905 		if (conn->auth.chap_phase != ISCSI_CHAP_PHASE_WAIT_NR) {
906 			SPDK_ERRLOG("CHAP sequence error\n");
907 			goto error_return;
908 		}
909 
910 		response = spdk_iscsi_param_get_val(params, "CHAP_R");
911 		if (response == NULL) {
912 			SPDK_ERRLOG("no response\n");
913 			goto error_return;
914 		}
915 		if (response[0] == '0' &&
916 		    (response[1] == 'x' || response[1] == 'X')) {
917 			rc = hex2bin(resmd5, SPDK_MD5DIGEST_LEN, response);
918 			if (rc < 0 || rc != SPDK_MD5DIGEST_LEN) {
919 				SPDK_ERRLOG("response format error\n");
920 				goto error_return;
921 			}
922 		} else if (response[0] == '0' &&
923 			   (response[1] == 'b' || response[1] == 'B')) {
924 			response += 2;
925 			rc = spdk_base64_decode(resmd5, &decoded_len, response);
926 			if (rc < 0 || decoded_len != SPDK_MD5DIGEST_LEN) {
927 				SPDK_ERRLOG("response format error\n");
928 				goto error_return;
929 			}
930 		} else {
931 			SPDK_ERRLOG("response format error\n");
932 			goto error_return;
933 		}
934 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "got CHAP_N/CHAP_R\n");
935 
936 		rc = iscsi_get_authinfo(conn, name);
937 		if (rc < 0) {
938 			/* SPDK_ERRLOG("auth user or secret is missing\n"); */
939 			SPDK_ERRLOG("iscsi_get_authinfo() failed\n");
940 			goto error_return;
941 		}
942 		if (conn->auth.user[0] == '\0' || conn->auth.secret[0] == '\0') {
943 			/* SPDK_ERRLOG("auth user or secret is missing\n"); */
944 			SPDK_ERRLOG("auth failed (name %.64s)\n", name);
945 			goto error_return;
946 		}
947 
948 		spdk_md5init(&md5ctx);
949 		/* Identifier */
950 		spdk_md5update(&md5ctx, conn->auth.chap_id, 1);
951 		/* followed by secret */
952 		spdk_md5update(&md5ctx, conn->auth.secret,
953 			       strlen(conn->auth.secret));
954 		/* followed by Challenge Value */
955 		spdk_md5update(&md5ctx, conn->auth.chap_challenge,
956 			       conn->auth.chap_challenge_len);
957 		/* tgtmd5 is expecting Response Value */
958 		spdk_md5final(tgtmd5, &md5ctx);
959 
960 		bin2hex(in_val, ISCSI_TEXT_MAX_VAL_LEN, tgtmd5, SPDK_MD5DIGEST_LEN);
961 
962 #if 0
963 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "tgtmd5=%s, resmd5=%s\n", in_val, response);
964 		spdk_dump("tgtmd5", tgtmd5, SPDK_MD5DIGEST_LEN);
965 		spdk_dump("resmd5", resmd5, SPDK_MD5DIGEST_LEN);
966 #endif
967 
968 		/* compare MD5 digest */
969 		if (memcmp(tgtmd5, resmd5, SPDK_MD5DIGEST_LEN) != 0) {
970 			/* not match */
971 			/* SPDK_ERRLOG("auth user or secret is missing\n"); */
972 			SPDK_ERRLOG("auth failed (name %.64s)\n", name);
973 			goto error_return;
974 		}
975 		/* OK initiator's secret */
976 		conn->authenticated = true;
977 
978 		/* mutual CHAP? */
979 		identifier = spdk_iscsi_param_get_val(params, "CHAP_I");
980 		if (identifier != NULL) {
981 			conn->auth.chap_mid[0] = (uint8_t) strtol(identifier, NULL, 10);
982 			challenge = spdk_iscsi_param_get_val(params, "CHAP_C");
983 			if (challenge == NULL) {
984 				SPDK_ERRLOG("CHAP sequence error\n");
985 				goto error_return;
986 			}
987 			if (challenge[0] == '0' &&
988 			    (challenge[1] == 'x' || challenge[1] == 'X')) {
989 				rc = hex2bin(conn->auth.chap_mchallenge,
990 					     ISCSI_CHAP_CHALLENGE_LEN, challenge);
991 				if (rc < 0) {
992 					SPDK_ERRLOG("challenge format error\n");
993 					goto error_return;
994 				}
995 				conn->auth.chap_mchallenge_len = rc;
996 			} else if (challenge[0] == '0' &&
997 				   (challenge[1] == 'b' || challenge[1] == 'B')) {
998 				challenge += 2;
999 				rc = spdk_base64_decode(conn->auth.chap_mchallenge,
1000 							&decoded_len, challenge);
1001 				if (rc < 0) {
1002 					SPDK_ERRLOG("challenge format error\n");
1003 					goto error_return;
1004 				}
1005 				conn->auth.chap_mchallenge_len = decoded_len;
1006 			} else {
1007 				SPDK_ERRLOG("challenge format error\n");
1008 				goto error_return;
1009 			}
1010 #if 0
1011 			spdk_dump("MChallenge", conn->auth.chap_mchallenge,
1012 				  conn->auth.chap_mchallenge_len);
1013 #endif
1014 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "got CHAP_I/CHAP_C\n");
1015 
1016 			if (conn->auth.muser[0] == '\0' || conn->auth.msecret[0] == '\0') {
1017 				/* SPDK_ERRLOG("mutual auth user or secret is missing\n"); */
1018 				SPDK_ERRLOG("auth failed (name %.64s)\n", name);
1019 				goto error_return;
1020 			}
1021 
1022 			spdk_md5init(&md5ctx);
1023 			/* Identifier */
1024 			spdk_md5update(&md5ctx, conn->auth.chap_mid, 1);
1025 			/* followed by secret */
1026 			spdk_md5update(&md5ctx, conn->auth.msecret,
1027 				       strlen(conn->auth.msecret));
1028 			/* followed by Challenge Value */
1029 			spdk_md5update(&md5ctx, conn->auth.chap_mchallenge,
1030 				       conn->auth.chap_mchallenge_len);
1031 			/* tgtmd5 is Response Value */
1032 			spdk_md5final(tgtmd5, &md5ctx);
1033 
1034 			bin2hex(in_val, ISCSI_TEXT_MAX_VAL_LEN, tgtmd5, SPDK_MD5DIGEST_LEN);
1035 
1036 			total = iscsi_append_text(conn, "CHAP_N",
1037 						  conn->auth.muser, data, alloc_len, total);
1038 			total = iscsi_append_text(conn, "CHAP_R",
1039 						  in_val, data, alloc_len, total);
1040 		} else {
1041 			/* not mutual */
1042 			if (conn->mutual_chap) {
1043 				SPDK_ERRLOG("required mutual CHAP\n");
1044 				goto error_return;
1045 			}
1046 		}
1047 
1048 		conn->auth.chap_phase = ISCSI_CHAP_PHASE_END;
1049 	} else {
1050 		/* not found CHAP keys */
1051 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "start CHAP\n");
1052 		conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_A;
1053 	}
1054 
1055 	free(in_val);
1056 	return total;
1057 
1058 error_return:
1059 	conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_A;
1060 	free(in_val);
1061 	return -1;
1062 }
1063 
1064 static int
1065 iscsi_reject(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu,
1066 	     int reason)
1067 {
1068 	struct spdk_iscsi_pdu *rsp_pdu;
1069 	struct iscsi_bhs_reject *rsph;
1070 	uint8_t *data;
1071 	int total_ahs_len;
1072 	int data_len;
1073 	int alloc_len;
1074 
1075 	total_ahs_len = pdu->bhs.total_ahs_len;
1076 	data_len = 0;
1077 	alloc_len = ISCSI_BHS_LEN + (4 * total_ahs_len);
1078 
1079 	if (conn->header_digest) {
1080 		alloc_len += ISCSI_DIGEST_LEN;
1081 	}
1082 
1083 	data = calloc(1, alloc_len);
1084 	if (!data) {
1085 		SPDK_ERRLOG("calloc() failed for data segment\n");
1086 		return -ENOMEM;
1087 	}
1088 
1089 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Reject PDU reason=%d\n", reason);
1090 
1091 	if (conn->sess != NULL) {
1092 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI,
1093 			      "StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
1094 			      conn->StatSN, conn->sess->ExpCmdSN,
1095 			      conn->sess->MaxCmdSN);
1096 	} else {
1097 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "StatSN=%u\n", conn->StatSN);
1098 	}
1099 
1100 	memcpy(data, &pdu->bhs, ISCSI_BHS_LEN);
1101 	data_len += ISCSI_BHS_LEN;
1102 
1103 	if (total_ahs_len != 0) {
1104 		memcpy(data + data_len, pdu->ahs, (4 * total_ahs_len));
1105 		data_len += (4 * total_ahs_len);
1106 	}
1107 
1108 	if (conn->header_digest) {
1109 		memcpy(data + data_len, pdu->header_digest, ISCSI_DIGEST_LEN);
1110 		data_len += ISCSI_DIGEST_LEN;
1111 	}
1112 
1113 	rsp_pdu = spdk_get_pdu();
1114 	if (rsp_pdu == NULL) {
1115 		free(data);
1116 		return -ENOMEM;
1117 	}
1118 
1119 	rsph = (struct iscsi_bhs_reject *)&rsp_pdu->bhs;
1120 	rsp_pdu->data = data;
1121 	rsph->opcode = ISCSI_OP_REJECT;
1122 	rsph->flags |= 0x80;	/* bit 0 is default to 1 */
1123 	rsph->reason = reason;
1124 	DSET24(rsph->data_segment_len, data_len);
1125 
1126 	rsph->ffffffff = 0xffffffffU;
1127 	to_be32(&rsph->stat_sn, conn->StatSN);
1128 	conn->StatSN++;
1129 
1130 	if (conn->sess != NULL) {
1131 		to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
1132 		to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
1133 	} else {
1134 		to_be32(&rsph->exp_cmd_sn, 1);
1135 		to_be32(&rsph->max_cmd_sn, 1);
1136 	}
1137 
1138 	SPDK_LOGDUMP(SPDK_LOG_ISCSI, "PDU", (void *)&rsp_pdu->bhs, ISCSI_BHS_LEN);
1139 
1140 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
1141 
1142 	return 0;
1143 }
1144 
1145 static int
1146 iscsi_check_values(struct spdk_iscsi_conn *conn)
1147 {
1148 	if (conn->sess->FirstBurstLength > conn->sess->MaxBurstLength) {
1149 		SPDK_ERRLOG("FirstBurstLength(%d) > MaxBurstLength(%d)\n",
1150 			    conn->sess->FirstBurstLength,
1151 			    conn->sess->MaxBurstLength);
1152 		return -1;
1153 	}
1154 	if (conn->sess->FirstBurstLength > g_spdk_iscsi.FirstBurstLength) {
1155 		SPDK_ERRLOG("FirstBurstLength(%d) > iSCSI target restriction(%d)\n",
1156 			    conn->sess->FirstBurstLength, g_spdk_iscsi.FirstBurstLength);
1157 		return -1;
1158 	}
1159 	if (conn->sess->MaxBurstLength > 0x00ffffff) {
1160 		SPDK_ERRLOG("MaxBurstLength(%d) > 0x00ffffff\n",
1161 			    conn->sess->MaxBurstLength);
1162 		return -1;
1163 	}
1164 
1165 	if (conn->MaxRecvDataSegmentLength < 512) {
1166 		SPDK_ERRLOG("MaxRecvDataSegmentLength(%d) < 512\n",
1167 			    conn->MaxRecvDataSegmentLength);
1168 		return -1;
1169 	}
1170 	if (conn->MaxRecvDataSegmentLength > 0x00ffffff) {
1171 		SPDK_ERRLOG("MaxRecvDataSegmentLength(%d) > 0x00ffffff\n",
1172 			    conn->MaxRecvDataSegmentLength);
1173 		return -1;
1174 	}
1175 	return 0;
1176 }
1177 
1178 /*
1179  * The response function of spdk_iscsi_op_login
1180  * return:
1181  * 0:success;
1182  * -1:error;
1183  */
1184 static int
1185 iscsi_op_login_response(struct spdk_iscsi_conn *conn,
1186 			struct spdk_iscsi_pdu *rsp_pdu, struct iscsi_param *params)
1187 {
1188 	struct iscsi_bhs_login_rsp *rsph;
1189 	int rc;
1190 
1191 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1192 	rsph->version_max = ISCSI_VERSION;
1193 	rsph->version_act = ISCSI_VERSION;
1194 	DSET24(rsph->data_segment_len, rsp_pdu->data_segment_len);
1195 
1196 	to_be32(&rsph->stat_sn, conn->StatSN);
1197 	conn->StatSN++;
1198 
1199 	if (conn->sess != NULL) {
1200 		to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
1201 		to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
1202 	} else {
1203 		to_be32(&rsph->exp_cmd_sn, rsp_pdu->cmd_sn);
1204 		to_be32(&rsph->max_cmd_sn, rsp_pdu->cmd_sn);
1205 	}
1206 
1207 	SPDK_LOGDUMP(SPDK_LOG_ISCSI, "PDU", (uint8_t *)rsph, ISCSI_BHS_LEN);
1208 	SPDK_LOGDUMP(SPDK_LOG_ISCSI, "DATA", rsp_pdu->data, rsp_pdu->data_segment_len);
1209 
1210 	/* Set T/CSG/NSG to reserved if login error. */
1211 	if (rsph->status_class != 0) {
1212 		rsph->flags &= ~ISCSI_LOGIN_TRANSIT;
1213 		rsph->flags &= ~ISCSI_LOGIN_CURRENT_STAGE_MASK;
1214 		rsph->flags &= ~ISCSI_LOGIN_NEXT_STAGE_MASK;
1215 	}
1216 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
1217 
1218 	/* after send PDU digest on/off */
1219 	if (conn->full_feature) {
1220 		/* update internal variables */
1221 		rc = spdk_iscsi_copy_param2var(conn);
1222 		if (rc < 0) {
1223 			SPDK_ERRLOG("spdk_iscsi_copy_param2var() failed\n");
1224 			spdk_iscsi_param_free(params);
1225 			return -1;
1226 		}
1227 		/* check value */
1228 		rc = iscsi_check_values(conn);
1229 		if (rc < 0) {
1230 			SPDK_ERRLOG("iscsi_check_values() failed\n");
1231 			spdk_iscsi_param_free(params);
1232 			return -1;
1233 		}
1234 	}
1235 
1236 	spdk_iscsi_param_free(params);
1237 	return 0;
1238 }
1239 
1240 /*
1241  * This function is used to del the original param and update it with new
1242  * value
1243  * return:
1244  * 0: success
1245  * otherwise: error
1246  */
1247 static int
1248 iscsi_op_login_update_param(struct spdk_iscsi_conn *conn,
1249 			    const char *key, const char *value,
1250 			    const char *list)
1251 {
1252 	int rc = 0;
1253 	struct iscsi_param *new_param, *orig_param;
1254 	int index;
1255 
1256 	orig_param = spdk_iscsi_param_find(conn->params, key);
1257 	if (orig_param == NULL) {
1258 		SPDK_ERRLOG("orig_param %s not found\n", key);
1259 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1260 	}
1261 
1262 	index = orig_param->state_index;
1263 	rc = spdk_iscsi_param_del(&conn->params, key);
1264 	if (rc < 0) {
1265 		SPDK_ERRLOG("iscsi_param_del(%s) failed\n", key);
1266 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1267 	}
1268 	rc = spdk_iscsi_param_add(&conn->params, key, value, list, ISPT_LIST);
1269 	if (rc < 0) {
1270 		SPDK_ERRLOG("iscsi_param_add() failed\n");
1271 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1272 	}
1273 	new_param = spdk_iscsi_param_find(conn->params, key);
1274 	if (new_param == NULL) {
1275 		SPDK_ERRLOG("spdk_iscsi_param_find() failed\n");
1276 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1277 	}
1278 	new_param->state_index = index;
1279 	return rc;
1280 }
1281 
1282 static int
1283 iscsi_negotiate_chap_param(struct spdk_iscsi_conn *conn, bool disable_chap,
1284 			   bool require_chap, bool mutual_chap)
1285 {
1286 	int rc = 0;
1287 
1288 	if (disable_chap) {
1289 		conn->require_chap = false;
1290 		rc = iscsi_op_login_update_param(conn, "AuthMethod", "None", "None");
1291 		if (rc < 0) {
1292 			return rc;
1293 		}
1294 	} else if (require_chap) {
1295 		conn->require_chap = true;
1296 		rc = iscsi_op_login_update_param(conn, "AuthMethod", "CHAP", "CHAP");
1297 		if (rc < 0) {
1298 			return rc;
1299 		}
1300 	}
1301 	if (mutual_chap) {
1302 		conn->mutual_chap = true;
1303 	}
1304 
1305 	return rc;
1306 }
1307 
1308 /*
1309  * The function which is used to handle the part of session discovery
1310  * return:
1311  * 0, success;
1312  * otherwise: error;
1313  */
1314 static int
1315 iscsi_op_login_session_discovery_chap(struct spdk_iscsi_conn *conn)
1316 {
1317 	return iscsi_negotiate_chap_param(conn, g_spdk_iscsi.disable_chap,
1318 					  g_spdk_iscsi.require_chap,
1319 					  g_spdk_iscsi.mutual_chap);
1320 }
1321 
1322 /*
1323  * This function is used to update the param related with chap
1324  * return:
1325  * 0: success
1326  * otherwise: error
1327  */
1328 static int
1329 iscsi_op_login_negotiate_chap_param(struct spdk_iscsi_conn *conn,
1330 				    struct spdk_iscsi_tgt_node *target)
1331 {
1332 	return iscsi_negotiate_chap_param(conn, target->disable_chap,
1333 					  target->require_chap,
1334 					  target->mutual_chap);
1335 }
1336 
1337 static int
1338 iscsi_op_login_negotiate_digest_param(struct spdk_iscsi_conn *conn,
1339 				      struct spdk_iscsi_tgt_node *target)
1340 {
1341 	int rc;
1342 
1343 	if (target->header_digest) {
1344 		/*
1345 		 * User specified header digests, so update the list of
1346 		 *  HeaderDigest values to remove "None" so that only
1347 		 *  initiators who support CRC32C can connect.
1348 		 */
1349 		rc = iscsi_op_login_update_param(conn, "HeaderDigest", "CRC32C", "CRC32C");
1350 		if (rc < 0) {
1351 			return rc;
1352 		}
1353 	}
1354 
1355 	if (target->data_digest) {
1356 		/*
1357 		 * User specified data digests, so update the list of
1358 		 *  DataDigest values to remove "None" so that only
1359 		 *  initiators who support CRC32C can connect.
1360 		 */
1361 		rc = iscsi_op_login_update_param(conn, "DataDigest", "CRC32C", "CRC32C");
1362 		if (rc < 0) {
1363 			return rc;
1364 		}
1365 	}
1366 
1367 	return 0;
1368 }
1369 
1370 /*
1371  * This function use to check the session
1372  * return:
1373  * 0, success
1374  * otherwise: error
1375  */
1376 static int
1377 iscsi_op_login_check_session(struct spdk_iscsi_conn *conn,
1378 			     struct spdk_iscsi_pdu *rsp_pdu,
1379 			     char *initiator_port_name, int cid)
1380 
1381 {
1382 	int rc = 0;
1383 	struct iscsi_bhs_login_rsp *rsph;
1384 
1385 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1386 	/* check existing session */
1387 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "isid=%"PRIx64", tsih=%u, cid=%u\n",
1388 		      iscsi_get_isid(rsph->isid), from_be16(&rsph->tsih), cid);
1389 	if (rsph->tsih != 0) {
1390 		/* multiple connections */
1391 		rc = append_iscsi_sess(conn, initiator_port_name,
1392 				       from_be16(&rsph->tsih), cid);
1393 		if (rc < 0) {
1394 			SPDK_ERRLOG("isid=%"PRIx64", tsih=%u, cid=%u:"
1395 				    "spdk_append_iscsi_sess() failed\n",
1396 				    iscsi_get_isid(rsph->isid), from_be16(&rsph->tsih),
1397 				    cid);
1398 			/* Can't include in session */
1399 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1400 			rsph->status_detail = ISCSI_LOGIN_CONN_ADD_FAIL;
1401 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1402 		}
1403 	} else if (!g_spdk_iscsi.AllowDuplicateIsid) {
1404 		/* new session, drop old sess by the initiator */
1405 		spdk_iscsi_drop_conns(conn, initiator_port_name, 0 /* drop old */);
1406 	}
1407 
1408 	return rc;
1409 }
1410 
1411 /*
1412  * This function is used to check the target info
1413  * return:
1414  * 0: success
1415  * otherwise: error
1416  */
1417 static int
1418 iscsi_op_login_check_target(struct spdk_iscsi_conn *conn,
1419 			    struct spdk_iscsi_pdu *rsp_pdu,
1420 			    const char *target_name,
1421 			    struct spdk_iscsi_tgt_node **target)
1422 {
1423 	bool result;
1424 	struct iscsi_bhs_login_rsp *rsph;
1425 
1426 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1427 	*target = spdk_iscsi_find_tgt_node(target_name);
1428 	if (*target == NULL) {
1429 		SPDK_WARNLOG("target %s not found\n", target_name);
1430 		/* Not found */
1431 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1432 		rsph->status_detail = ISCSI_LOGIN_TARGET_NOT_FOUND;
1433 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1434 	}
1435 	if (spdk_iscsi_tgt_node_is_destructed(*target)) {
1436 		SPDK_ERRLOG("target %s is removed\n", target_name);
1437 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1438 		rsph->status_detail = ISCSI_LOGIN_TARGET_REMOVED;
1439 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1440 	}
1441 	result = spdk_iscsi_tgt_node_access(conn, *target,
1442 					    conn->initiator_name,
1443 					    conn->initiator_addr);
1444 	if (!result) {
1445 		SPDK_ERRLOG("access denied\n");
1446 		/* Not found */
1447 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1448 		rsph->status_detail = ISCSI_LOGIN_TARGET_NOT_FOUND;
1449 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1450 	}
1451 
1452 	return 0;
1453 }
1454 
1455 /*
1456  * The function which is used to handle the part of normal login session
1457  * return:
1458  * 0, success;
1459  * SPDK_ISCSI_LOGIN_ERROR_PARAMETER, parameter error;
1460  */
1461 static int
1462 iscsi_op_login_session_normal(struct spdk_iscsi_conn *conn,
1463 			      struct spdk_iscsi_pdu *rsp_pdu,
1464 			      char *initiator_port_name,
1465 			      struct iscsi_param *params,
1466 			      struct spdk_iscsi_tgt_node **target,
1467 			      int cid)
1468 {
1469 	const char *target_name;
1470 	const char *target_short_name;
1471 	struct iscsi_bhs_login_rsp *rsph;
1472 	int rc = 0;
1473 
1474 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1475 	target_name = spdk_iscsi_param_get_val(params, "TargetName");
1476 
1477 	if (target_name == NULL) {
1478 		SPDK_ERRLOG("TargetName is empty\n");
1479 		/* Missing parameter */
1480 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1481 		rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1482 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1483 	}
1484 
1485 	memset(conn->target_short_name, 0, MAX_TARGET_NAME);
1486 	target_short_name = strstr(target_name, ":");
1487 	if (target_short_name != NULL) {
1488 		target_short_name++; /* Advance past the ':' */
1489 		if (strlen(target_short_name) >= MAX_TARGET_NAME) {
1490 			SPDK_ERRLOG("Target Short Name (%s) is more than %u characters\n",
1491 				    target_short_name, MAX_TARGET_NAME);
1492 			return rc;
1493 		}
1494 		snprintf(conn->target_short_name, MAX_TARGET_NAME, "%s",
1495 			 target_short_name);
1496 	}
1497 
1498 	pthread_mutex_lock(&g_spdk_iscsi.mutex);
1499 	rc = iscsi_op_login_check_target(conn, rsp_pdu, target_name, target);
1500 	pthread_mutex_unlock(&g_spdk_iscsi.mutex);
1501 
1502 	if (rc < 0) {
1503 		return rc;
1504 	}
1505 
1506 	conn->target = *target;
1507 	conn->dev = (*target)->dev;
1508 	conn->target_port = spdk_scsi_dev_find_port_by_id((*target)->dev,
1509 			    conn->portal->group->tag);
1510 
1511 	rc = iscsi_op_login_check_session(conn, rsp_pdu,
1512 					  initiator_port_name, cid);
1513 	if (rc < 0) {
1514 		return rc;
1515 	}
1516 
1517 	/* force target flags */
1518 	pthread_mutex_lock(&((*target)->mutex));
1519 	rc = iscsi_op_login_negotiate_chap_param(conn, *target);
1520 	pthread_mutex_unlock(&((*target)->mutex));
1521 
1522 	if (rc != 0) {
1523 		return rc;
1524 	}
1525 
1526 	return iscsi_op_login_negotiate_digest_param(conn, *target);
1527 }
1528 
1529 /*
1530  * This function is used to judge the session type
1531  * return
1532  * 0: success
1533  * otherwise, error
1534  */
1535 static int
1536 iscsi_op_login_session_type(struct spdk_iscsi_conn *conn,
1537 			    struct spdk_iscsi_pdu *rsp_pdu,
1538 			    enum session_type *session_type,
1539 			    struct iscsi_param *params)
1540 {
1541 	const char *session_type_str;
1542 	struct iscsi_bhs_login_rsp *rsph;
1543 
1544 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1545 	session_type_str = spdk_iscsi_param_get_val(params, "SessionType");
1546 	if (session_type_str == NULL) {
1547 		if (rsph->tsih != 0) {
1548 			*session_type = SESSION_TYPE_NORMAL;
1549 		} else {
1550 			SPDK_ERRLOG("SessionType is empty\n");
1551 			/* Missing parameter */
1552 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1553 			rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1554 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1555 		}
1556 	} else {
1557 		if (strcasecmp(session_type_str, "Discovery") == 0) {
1558 			*session_type = SESSION_TYPE_DISCOVERY;
1559 		} else if (strcasecmp(session_type_str, "Normal") == 0) {
1560 			*session_type = SESSION_TYPE_NORMAL;
1561 		} else {
1562 			*session_type = SESSION_TYPE_INVALID;
1563 			SPDK_ERRLOG("SessionType is invalid\n");
1564 			/* Missing parameter */
1565 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1566 			rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1567 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1568 		}
1569 	}
1570 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Session Type: %s\n", session_type_str);
1571 
1572 	return 0;
1573 }
1574 /*
1575  * This function is used to initialize the port info
1576  * return
1577  * 0: success
1578  * otherwise: error
1579  */
1580 static int
1581 iscsi_op_login_initialize_port(struct spdk_iscsi_conn *conn,
1582 			       struct spdk_iscsi_pdu *rsp_pdu,
1583 			       char *initiator_port_name,
1584 			       uint32_t name_length,
1585 			       struct iscsi_param *params)
1586 {
1587 	const char *val;
1588 	struct iscsi_bhs_login_rsp *rsph;
1589 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1590 
1591 	/* Initiator Name and Port */
1592 	val = spdk_iscsi_param_get_val(params, "InitiatorName");
1593 	if (val == NULL) {
1594 		SPDK_ERRLOG("InitiatorName is empty\n");
1595 		/* Missing parameter */
1596 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1597 		rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1598 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1599 	}
1600 	snprintf(conn->initiator_name, sizeof(conn->initiator_name), "%s", val);
1601 	snprintf(initiator_port_name, name_length,
1602 		 "%s,i,0x%12.12" PRIx64, val, iscsi_get_isid(rsph->isid));
1603 	spdk_strlwr(conn->initiator_name);
1604 	spdk_strlwr(initiator_port_name);
1605 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Initiator name: %s\n", conn->initiator_name);
1606 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Initiator port: %s\n", initiator_port_name);
1607 
1608 	return 0;
1609 }
1610 
1611 /*
1612  * This function is used to set the info in the connection data structure
1613  * return
1614  * 0: success
1615  * otherwise: error
1616  */
1617 static int
1618 iscsi_op_login_set_conn_info(struct spdk_iscsi_conn *conn,
1619 			     struct spdk_iscsi_pdu *rsp_pdu,
1620 			     char *initiator_port_name,
1621 			     enum session_type session_type,
1622 			     struct spdk_iscsi_tgt_node *target, int cid)
1623 {
1624 	int rc = 0;
1625 	struct iscsi_bhs_login_rsp *rsph;
1626 	struct spdk_scsi_port *initiator_port;
1627 
1628 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1629 	conn->authenticated = false;
1630 	conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_A;
1631 	conn->cid = cid;
1632 
1633 	if (conn->sess == NULL) {
1634 		/* create initiator port */
1635 		initiator_port = spdk_scsi_port_create(iscsi_get_isid(rsph->isid), 0, initiator_port_name);
1636 		if (initiator_port == NULL) {
1637 			SPDK_ERRLOG("create_port() failed\n");
1638 			rsph->status_class = ISCSI_CLASS_TARGET_ERROR;
1639 			rsph->status_detail = ISCSI_LOGIN_STATUS_NO_RESOURCES;
1640 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1641 		}
1642 
1643 		/* new session */
1644 		rc = create_iscsi_sess(conn, target, session_type);
1645 		if (rc < 0) {
1646 			spdk_scsi_port_free(&initiator_port);
1647 			SPDK_ERRLOG("create_sess() failed\n");
1648 			rsph->status_class = ISCSI_CLASS_TARGET_ERROR;
1649 			rsph->status_detail = ISCSI_LOGIN_STATUS_NO_RESOURCES;
1650 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1651 		}
1652 		/* initialize parameters */
1653 		conn->sess->initiator_port = initiator_port;
1654 		conn->StatSN = from_be32(&rsph->stat_sn);
1655 		conn->sess->isid = iscsi_get_isid(rsph->isid);
1656 
1657 		/* Initiator port TransportID */
1658 		spdk_scsi_port_set_iscsi_transport_id(conn->sess->initiator_port,
1659 						      conn->initiator_name,
1660 						      conn->sess->isid);
1661 
1662 		/* Discovery sessions will not have a target. */
1663 		if (target != NULL) {
1664 			conn->sess->queue_depth = target->queue_depth;
1665 		} else {
1666 			/*
1667 			 * Assume discovery sessions have an effective command
1668 			 *  windows size of 1.
1669 			 */
1670 			conn->sess->queue_depth = 1;
1671 		}
1672 		conn->sess->ExpCmdSN = rsp_pdu->cmd_sn;
1673 		conn->sess->MaxCmdSN = rsp_pdu->cmd_sn + conn->sess->queue_depth - 1;
1674 	}
1675 
1676 	conn->initiator_port = conn->sess->initiator_port;
1677 
1678 	return 0;
1679 }
1680 
1681 /*
1682  * This function is used to set the target info
1683  * return
1684  * 0: success
1685  * otherwise: error
1686  */
1687 static int
1688 iscsi_op_login_set_target_info(struct spdk_iscsi_conn *conn,
1689 			       struct spdk_iscsi_pdu *rsp_pdu,
1690 			       enum session_type session_type,
1691 			       int alloc_len,
1692 			       struct spdk_iscsi_tgt_node *target)
1693 {
1694 	char buf[MAX_TMPBUF];
1695 	const char *val;
1696 	int rc = 0;
1697 	struct spdk_iscsi_portal *portal = conn->portal;
1698 
1699 	/* declarative parameters */
1700 	if (target != NULL) {
1701 		pthread_mutex_lock(&target->mutex);
1702 		if (target->alias != NULL) {
1703 			snprintf(buf, sizeof buf, "%s", target->alias);
1704 		} else {
1705 			snprintf(buf, sizeof buf, "%s", "");
1706 		}
1707 		pthread_mutex_unlock(&target->mutex);
1708 		rc = spdk_iscsi_param_set(conn->sess->params, "TargetAlias", buf);
1709 		if (rc < 0) {
1710 			SPDK_ERRLOG("iscsi_param_set() failed\n");
1711 			return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1712 		}
1713 	}
1714 	snprintf(buf, sizeof buf, "%s:%s,%d", portal->host, portal->port,
1715 		 portal->group->tag);
1716 	rc = spdk_iscsi_param_set(conn->sess->params, "TargetAddress", buf);
1717 	if (rc < 0) {
1718 		SPDK_ERRLOG("iscsi_param_set() failed\n");
1719 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1720 	}
1721 	snprintf(buf, sizeof buf, "%d", portal->group->tag);
1722 	rc = spdk_iscsi_param_set(conn->sess->params, "TargetPortalGroupTag", buf);
1723 	if (rc < 0) {
1724 		SPDK_ERRLOG("iscsi_param_set() failed\n");
1725 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1726 	}
1727 
1728 	/* write in response */
1729 	if (target != NULL) {
1730 		val = spdk_iscsi_param_get_val(conn->sess->params, "TargetAlias");
1731 		if (val != NULL && strlen(val) != 0) {
1732 			rsp_pdu->data_segment_len = iscsi_append_param(conn,
1733 						    "TargetAlias",
1734 						    rsp_pdu->data,
1735 						    alloc_len,
1736 						    rsp_pdu->data_segment_len);
1737 		}
1738 		if (session_type == SESSION_TYPE_DISCOVERY) {
1739 			rsp_pdu->data_segment_len = iscsi_append_param(conn,
1740 						    "TargetAddress",
1741 						    rsp_pdu->data,
1742 						    alloc_len,
1743 						    rsp_pdu->data_segment_len);
1744 		}
1745 		rsp_pdu->data_segment_len = iscsi_append_param(conn,
1746 					    "TargetPortalGroupTag",
1747 					    rsp_pdu->data,
1748 					    alloc_len,
1749 					    rsp_pdu->data_segment_len);
1750 	}
1751 
1752 	return rc;
1753 }
1754 
1755 /*
1756  * This function is used to handle the login of iscsi initiator when there is
1757  * no session
1758  * return:
1759  * 0, success;
1760  * SPDK_ISCSI_LOGIN_ERROR_PARAMETER, parameter error;
1761  * SPDK_ISCSI_LOGIN_ERROR_RESPONSE,  used to notify the login fail.
1762  */
1763 static int
1764 iscsi_op_login_phase_none(struct spdk_iscsi_conn *conn,
1765 			  struct spdk_iscsi_pdu *rsp_pdu,
1766 			  struct iscsi_param *params,
1767 			  int alloc_len, int cid)
1768 {
1769 	enum session_type session_type;
1770 	char initiator_port_name[MAX_INITIATOR_PORT_NAME];
1771 	struct iscsi_bhs_login_rsp *rsph;
1772 	struct spdk_iscsi_tgt_node *target = NULL;
1773 	int rc = 0;
1774 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1775 
1776 	conn->target = NULL;
1777 	conn->dev = NULL;
1778 
1779 	rc = iscsi_op_login_initialize_port(conn, rsp_pdu, initiator_port_name,
1780 					    MAX_INITIATOR_PORT_NAME, params);
1781 	if (rc < 0) {
1782 		return rc;
1783 	}
1784 
1785 	rc = iscsi_op_login_session_type(conn, rsp_pdu, &session_type, params);
1786 	if (rc < 0) {
1787 		return rc;
1788 	}
1789 
1790 	/* Target Name and Port */
1791 	if (session_type == SESSION_TYPE_NORMAL) {
1792 		rc = iscsi_op_login_session_normal(conn, rsp_pdu,
1793 						   initiator_port_name,
1794 						   params, &target, cid);
1795 		if (rc < 0) {
1796 			return rc;
1797 		}
1798 
1799 	} else if (session_type == SESSION_TYPE_DISCOVERY) {
1800 		target = NULL;
1801 		rsph->tsih = 0;
1802 
1803 		/* force target flags */
1804 		pthread_mutex_lock(&g_spdk_iscsi.mutex);
1805 		rc = iscsi_op_login_session_discovery_chap(conn);
1806 		pthread_mutex_unlock(&g_spdk_iscsi.mutex);
1807 		if (rc < 0) {
1808 			return rc;
1809 		}
1810 	} else {
1811 		SPDK_ERRLOG("unknown session type\n");
1812 		/* Missing parameter */
1813 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1814 		rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1815 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1816 	}
1817 
1818 	rc = iscsi_op_login_set_conn_info(conn, rsp_pdu, initiator_port_name,
1819 					  session_type, target, cid);
1820 	if (rc < 0) {
1821 		return rc;
1822 	}
1823 
1824 	/* limit conns on discovery session */
1825 	if (session_type == SESSION_TYPE_DISCOVERY) {
1826 		conn->sess->MaxConnections = 1;
1827 		rc = spdk_iscsi_param_set_int(conn->sess->params,
1828 					      "MaxConnections",
1829 					      conn->sess->MaxConnections);
1830 		if (rc < 0) {
1831 			SPDK_ERRLOG("iscsi_param_set_int() failed\n");
1832 			return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1833 		}
1834 	}
1835 
1836 	return iscsi_op_login_set_target_info(conn, rsp_pdu, session_type,
1837 					      alloc_len, target);
1838 }
1839 
1840 /*
1841  * The function which is used to initialize the internal response data
1842  * structure of iscsi login function.
1843  * return:
1844  * 0, success;
1845  * otherwise, error;
1846  */
1847 static int
1848 iscsi_op_login_rsp_init(struct spdk_iscsi_conn *conn,
1849 			struct spdk_iscsi_pdu *pdu, struct spdk_iscsi_pdu *rsp_pdu,
1850 			struct iscsi_param **params, int *alloc_len, int *cid)
1851 {
1852 	struct iscsi_bhs_login_req *reqh;
1853 	struct iscsi_bhs_login_rsp *rsph;
1854 	int rc;
1855 
1856 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1857 	rsph->opcode = ISCSI_OP_LOGIN_RSP;
1858 	rsph->status_class = ISCSI_CLASS_SUCCESS;
1859 	rsph->status_detail = ISCSI_LOGIN_ACCEPT;
1860 	rsp_pdu->data_segment_len = 0;
1861 
1862 	/* Default MaxRecvDataSegmentLength - RFC3720(12.12) */
1863 	if (conn->MaxRecvDataSegmentLength < 8192) {
1864 		*alloc_len = 8192;
1865 	} else {
1866 		*alloc_len = conn->MaxRecvDataSegmentLength;
1867 	}
1868 
1869 	rsp_pdu->data = calloc(1, *alloc_len);
1870 	if (!rsp_pdu->data) {
1871 		SPDK_ERRLOG("calloc() failed for data segment\n");
1872 		return -ENOMEM;
1873 	}
1874 
1875 	reqh = (struct iscsi_bhs_login_req *)&pdu->bhs;
1876 	rsph->flags |= (reqh->flags & ISCSI_LOGIN_TRANSIT);
1877 	rsph->flags |= (reqh->flags & ISCSI_LOGIN_CONTINUE);
1878 	rsph->flags |= (reqh->flags & ISCSI_LOGIN_CURRENT_STAGE_MASK);
1879 	if (ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags)) {
1880 		rsph->flags |= (reqh->flags & ISCSI_LOGIN_NEXT_STAGE_MASK);
1881 	}
1882 
1883 	/* We don't need to convert from network byte order. Just store it */
1884 	memcpy(&rsph->isid, reqh->isid, 6);
1885 	rsph->tsih = reqh->tsih;
1886 	rsph->itt = reqh->itt;
1887 	rsp_pdu->cmd_sn = from_be32(&reqh->cmd_sn);
1888 	*cid = from_be16(&reqh->cid);
1889 
1890 	if (rsph->tsih) {
1891 		rsph->stat_sn = reqh->exp_stat_sn;
1892 	}
1893 
1894 	SPDK_LOGDUMP(SPDK_LOG_ISCSI, "PDU", (uint8_t *)&pdu->bhs, ISCSI_BHS_LEN);
1895 
1896 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI,
1897 		      "T=%d, C=%d, CSG=%d, NSG=%d, Min=%d, Max=%d, ITT=%x\n",
1898 		      ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags),
1899 		      ISCSI_BHS_LOGIN_GET_CBIT(rsph->flags),
1900 		      ISCSI_BHS_LOGIN_GET_CSG(rsph->flags),
1901 		      ISCSI_BHS_LOGIN_GET_NSG(rsph->flags),
1902 		      reqh->version_min, reqh->version_max, from_be32(&rsph->itt));
1903 
1904 	if (conn->sess != NULL) {
1905 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI,
1906 			      "CmdSN=%u, ExpStatSN=%u, StatSN=%u, ExpCmdSN=%u,"
1907 			      "MaxCmdSN=%u\n", rsp_pdu->cmd_sn,
1908 			      from_be32(&rsph->stat_sn), conn->StatSN,
1909 			      conn->sess->ExpCmdSN,
1910 			      conn->sess->MaxCmdSN);
1911 	} else {
1912 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI,
1913 			      "CmdSN=%u, ExpStatSN=%u, StatSN=%u\n",
1914 			      rsp_pdu->cmd_sn, from_be32(&rsph->stat_sn),
1915 			      conn->StatSN);
1916 	}
1917 
1918 	if (ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags) &&
1919 	    ISCSI_BHS_LOGIN_GET_CBIT(rsph->flags)) {
1920 		SPDK_ERRLOG("transit error\n");
1921 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1922 	}
1923 	/* make sure reqh->version_max < ISCSI_VERSION */
1924 	if (reqh->version_min > ISCSI_VERSION) {
1925 		SPDK_ERRLOG("unsupported version %d/%d\n", reqh->version_min,
1926 			    reqh->version_max);
1927 		/* Unsupported version */
1928 		/* set all reserved flag to zero */
1929 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1930 		rsph->status_detail = ISCSI_LOGIN_UNSUPPORTED_VERSION;
1931 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1932 	}
1933 
1934 	if ((ISCSI_BHS_LOGIN_GET_NSG(rsph->flags) == ISCSI_NSG_RESERVED_CODE) &&
1935 	    ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags)) {
1936 		/* set NSG to zero */
1937 		rsph->flags &= ~ISCSI_LOGIN_NEXT_STAGE_MASK;
1938 		/* also set other bits to zero */
1939 		rsph->flags &= ~ISCSI_LOGIN_TRANSIT;
1940 		rsph->flags &= ~ISCSI_LOGIN_CURRENT_STAGE_MASK;
1941 		SPDK_ERRLOG("Received reserved NSG code: %d\n", ISCSI_NSG_RESERVED_CODE);
1942 		/* Initiator error */
1943 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1944 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
1945 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1946 	}
1947 
1948 	/* store incoming parameters */
1949 	rc = spdk_iscsi_parse_params(params, pdu->data,
1950 				     pdu->data_segment_len, ISCSI_BHS_LOGIN_GET_CBIT(reqh->flags),
1951 				     &conn->partial_text_parameter);
1952 	if (rc < 0) {
1953 		SPDK_ERRLOG("iscsi_parse_params() failed\n");
1954 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1955 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
1956 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1957 	}
1958 	return 0;
1959 }
1960 
1961 /*
1962  * This function is used to set the csg bit case in rsp
1963  * return:
1964  * 0, success
1965  * otherwise: error
1966  */
1967 static int
1968 iscsi_op_login_rsp_handle_csg_bit(struct spdk_iscsi_conn *conn,
1969 				  struct spdk_iscsi_pdu *rsp_pdu,
1970 				  struct iscsi_param *params, int alloc_len)
1971 {
1972 	const char *auth_method;
1973 	int rc;
1974 	struct iscsi_bhs_login_rsp *rsph;
1975 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1976 
1977 	switch (ISCSI_BHS_LOGIN_GET_CSG(rsph->flags)) {
1978 	case ISCSI_SECURITY_NEGOTIATION_PHASE:
1979 		/* SecurityNegotiation */
1980 		auth_method = spdk_iscsi_param_get_val(conn->params, "AuthMethod");
1981 		if (auth_method == NULL) {
1982 			SPDK_ERRLOG("AuthMethod is empty\n");
1983 			/* Missing parameter */
1984 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1985 			rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1986 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1987 		}
1988 		if (strcasecmp(auth_method, "None") == 0) {
1989 			conn->authenticated = true;
1990 		} else {
1991 			rc = iscsi_auth_params(conn, params, auth_method,
1992 					       rsp_pdu->data, alloc_len,
1993 					       rsp_pdu->data_segment_len);
1994 			if (rc < 0) {
1995 				SPDK_ERRLOG("iscsi_auth_params() failed\n");
1996 				/* Authentication failure */
1997 				rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1998 				rsph->status_detail = ISCSI_LOGIN_AUTHENT_FAIL;
1999 				return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2000 			}
2001 			rsp_pdu->data_segment_len = rc;
2002 			if (!conn->authenticated) {
2003 				/* not complete */
2004 				rsph->flags &= ~ISCSI_LOGIN_TRANSIT;
2005 			} else {
2006 				if (conn->auth.chap_phase != ISCSI_CHAP_PHASE_END) {
2007 					SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "CHAP phase not complete");
2008 				}
2009 			}
2010 
2011 			SPDK_LOGDUMP(SPDK_LOG_ISCSI, "Negotiated Auth Params",
2012 				     rsp_pdu->data, rsp_pdu->data_segment_len);
2013 		}
2014 		break;
2015 
2016 	case ISCSI_OPERATIONAL_NEGOTIATION_PHASE:
2017 		/* LoginOperationalNegotiation */
2018 		if (conn->state == ISCSI_CONN_STATE_INVALID) {
2019 			if (conn->require_chap) {
2020 				/* Authentication failure */
2021 				rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2022 				rsph->status_detail = ISCSI_LOGIN_AUTHENT_FAIL;
2023 				return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2024 			} else {
2025 				/* AuthMethod=None */
2026 				conn->authenticated = true;
2027 			}
2028 		}
2029 		if (!conn->authenticated) {
2030 			SPDK_ERRLOG("authentication error\n");
2031 			/* Authentication failure */
2032 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2033 			rsph->status_detail = ISCSI_LOGIN_AUTHENT_FAIL;
2034 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2035 		}
2036 		break;
2037 
2038 	case ISCSI_FULL_FEATURE_PHASE:
2039 		/* FullFeaturePhase */
2040 		SPDK_ERRLOG("XXX Login in FullFeaturePhase\n");
2041 		/* Initiator error */
2042 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2043 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2044 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2045 
2046 	default:
2047 		SPDK_ERRLOG("unknown stage\n");
2048 		/* Initiator error */
2049 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2050 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2051 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2052 	}
2053 
2054 	return 0;
2055 }
2056 
2057 /* This function is used to notify the session info
2058  * return
2059  * 0: success
2060  * otherwise: error
2061  */
2062 static int
2063 iscsi_op_login_notify_session_info(struct spdk_iscsi_conn *conn,
2064 				   struct spdk_iscsi_pdu *rsp_pdu)
2065 {
2066 	struct iscsi_bhs_login_rsp *rsph;
2067 
2068 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
2069 	if (conn->sess->session_type == SESSION_TYPE_NORMAL) {
2070 		/* normal session */
2071 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Login from %s (%s) on %s tgt_node%d"
2072 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2073 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2074 			      conn->initiator_name, conn->initiator_addr,
2075 			      conn->target->name, conn->target->num,
2076 			      conn->portal->host, conn->portal->port, conn->portal->group->tag,
2077 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2078 			      (spdk_iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2079 			       ? "on" : "off"),
2080 			      (spdk_iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2081 			       ? "on" : "off"));
2082 	} else if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
2083 		/* discovery session */
2084 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Login(discovery) from %s (%s) on"
2085 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2086 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2087 			      conn->initiator_name, conn->initiator_addr,
2088 			      conn->portal->host, conn->portal->port, conn->portal->group->tag,
2089 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2090 			      (spdk_iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2091 			       ? "on" : "off"),
2092 			      (spdk_iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2093 			       ? "on" : "off"));
2094 	} else {
2095 		SPDK_ERRLOG("unknown session type\n");
2096 		/* Initiator error */
2097 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2098 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2099 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2100 	}
2101 
2102 	return 0;
2103 }
2104 
2105 /*
2106  * This function is to handle the tbit cases
2107  * return
2108  * 0: success
2109  * otherwise error
2110  */
2111 static int
2112 iscsi_op_login_rsp_handle_t_bit(struct spdk_iscsi_conn *conn,
2113 				struct spdk_iscsi_pdu *rsp_pdu)
2114 {
2115 	int rc;
2116 	struct iscsi_bhs_login_rsp *rsph;
2117 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
2118 
2119 	switch (ISCSI_BHS_LOGIN_GET_NSG(rsph->flags)) {
2120 	case ISCSI_SECURITY_NEGOTIATION_PHASE:
2121 		/* SecurityNegotiation */
2122 		conn->login_phase = ISCSI_SECURITY_NEGOTIATION_PHASE;
2123 		break;
2124 
2125 	case ISCSI_OPERATIONAL_NEGOTIATION_PHASE:
2126 		/* LoginOperationalNegotiation */
2127 		conn->login_phase = ISCSI_OPERATIONAL_NEGOTIATION_PHASE;
2128 		break;
2129 
2130 	case ISCSI_FULL_FEATURE_PHASE:
2131 		/* FullFeaturePhase */
2132 		conn->login_phase = ISCSI_FULL_FEATURE_PHASE;
2133 		to_be16(&rsph->tsih, conn->sess->tsih);
2134 
2135 		rc = iscsi_op_login_notify_session_info(conn, rsp_pdu);
2136 		if (rc < 0) {
2137 			return rc;
2138 		}
2139 
2140 		conn->full_feature = 1;
2141 		spdk_iscsi_conn_schedule(conn);
2142 		break;
2143 
2144 	default:
2145 		SPDK_ERRLOG("unknown stage\n");
2146 		/* Initiator error */
2147 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2148 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2149 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2150 	}
2151 
2152 	return 0;
2153 }
2154 
2155 /*
2156  * This function is used to set the values of the internal data structure used
2157  * by spdk_iscsi_op_login function
2158  * return:
2159  * 0, used to notify the a successful login
2160  * SPDK_ISCSI_LOGIN_ERROR_RESPONSE,  used to notify a failure login.
2161  */
2162 static int
2163 iscsi_op_login_rsp_handle(struct spdk_iscsi_conn *conn,
2164 			  struct spdk_iscsi_pdu *rsp_pdu, struct iscsi_param **params,
2165 			  int alloc_len)
2166 {
2167 	int rc;
2168 	struct iscsi_bhs_login_rsp *rsph;
2169 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
2170 
2171 	/* negotiate parameters */
2172 	rc = spdk_iscsi_negotiate_params(conn, params, rsp_pdu->data, alloc_len,
2173 					 rsp_pdu->data_segment_len);
2174 	if (rc < 0) {
2175 		/*
2176 		 * spdk_iscsi_negotiate_params just returns -1 on failure,
2177 		 *  so translate this into meaningful response codes and
2178 		 *  return values.
2179 		 */
2180 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2181 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2182 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2183 	}
2184 
2185 	rsp_pdu->data_segment_len = rc;
2186 	SPDK_LOGDUMP(SPDK_LOG_ISCSI, "Negotiated Params", rsp_pdu->data, rc);
2187 
2188 	/* handle the CSG bit case */
2189 	rc = iscsi_op_login_rsp_handle_csg_bit(conn, rsp_pdu, *params,
2190 					       alloc_len);
2191 	if (rc < 0) {
2192 		return rc;
2193 	}
2194 
2195 	/* handle the T bit case */
2196 	if (ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags)) {
2197 		rc = iscsi_op_login_rsp_handle_t_bit(conn, rsp_pdu);
2198 	}
2199 
2200 	return rc;
2201 }
2202 
2203 static int
2204 iscsi_op_login(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2205 {
2206 	int rc;
2207 	struct spdk_iscsi_pdu *rsp_pdu;
2208 	struct iscsi_param *params = NULL;
2209 	struct iscsi_param **params_p = &params;
2210 	int alloc_len;
2211 	int cid;
2212 
2213 	if (conn->full_feature && conn->sess != NULL &&
2214 	    conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
2215 		return SPDK_ISCSI_CONNECTION_FATAL;
2216 	}
2217 
2218 	rsp_pdu = spdk_get_pdu();
2219 	if (rsp_pdu == NULL) {
2220 		return SPDK_ISCSI_CONNECTION_FATAL;
2221 	}
2222 	rc = iscsi_op_login_rsp_init(conn, pdu, rsp_pdu, params_p,
2223 				     &alloc_len, &cid);
2224 	if (rc == SPDK_ISCSI_LOGIN_ERROR_RESPONSE || rc == SPDK_ISCSI_LOGIN_ERROR_PARAMETER) {
2225 		iscsi_op_login_response(conn, rsp_pdu, *params_p);
2226 		return rc;
2227 	}
2228 
2229 	/* For other values, we need to directly return */
2230 	if (rc < 0) {
2231 		spdk_put_pdu(rsp_pdu);
2232 		return rc;
2233 	}
2234 
2235 	if (conn->state == ISCSI_CONN_STATE_INVALID) {
2236 		rc = iscsi_op_login_phase_none(conn, rsp_pdu, *params_p,
2237 					       alloc_len, cid);
2238 		if (rc == SPDK_ISCSI_LOGIN_ERROR_RESPONSE || rc == SPDK_ISCSI_LOGIN_ERROR_PARAMETER) {
2239 			iscsi_op_login_response(conn, rsp_pdu, *params_p);
2240 			return rc;
2241 		}
2242 	}
2243 
2244 	rc = iscsi_op_login_rsp_handle(conn, rsp_pdu, params_p, alloc_len);
2245 	if (rc == SPDK_ISCSI_LOGIN_ERROR_RESPONSE) {
2246 		iscsi_op_login_response(conn, rsp_pdu, *params_p);
2247 		return rc;
2248 	}
2249 
2250 	rc = iscsi_op_login_response(conn, rsp_pdu, *params_p);
2251 	if (rc == 0) {
2252 		conn->state = ISCSI_CONN_STATE_RUNNING;
2253 	} else {
2254 		SPDK_ERRLOG("login error - connection will be destroyed\n");
2255 	}
2256 
2257 	return rc;
2258 }
2259 
2260 static int
2261 iscsi_op_text(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2262 {
2263 	struct iscsi_param *params = NULL;
2264 	struct iscsi_param **params_p = &params;
2265 	struct spdk_iscsi_pdu *rsp_pdu;
2266 	uint8_t *data;
2267 	uint64_t lun;
2268 	uint32_t task_tag;
2269 	uint32_t CmdSN;
2270 	uint32_t ExpStatSN;
2271 	const char *val;
2272 	int F_bit, C_bit;
2273 	int data_len;
2274 	int alloc_len;
2275 	int rc;
2276 	struct iscsi_bhs_text_req *reqh;
2277 	struct iscsi_bhs_text_resp *rsph;
2278 
2279 	data_len = 0;
2280 	alloc_len = conn->MaxRecvDataSegmentLength;
2281 
2282 	reqh = (struct iscsi_bhs_text_req *)&pdu->bhs;
2283 
2284 	F_bit = !!(reqh->flags & ISCSI_FLAG_FINAL);
2285 	C_bit = !!(reqh->flags & ISCSI_TEXT_CONTINUE);
2286 	lun = from_be64(&reqh->lun);
2287 	task_tag = from_be32(&reqh->itt);
2288 	CmdSN = from_be32(&reqh->cmd_sn);
2289 	pdu->cmd_sn = CmdSN;
2290 	ExpStatSN = from_be32(&reqh->exp_stat_sn);
2291 
2292 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "I=%d, F=%d, C=%d, ITT=%x, TTT=%x\n",
2293 		      reqh->immediate, F_bit, C_bit, task_tag, from_be32(&reqh->ttt));
2294 
2295 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI,
2296 		      "CmdSN=%u, ExpStatSN=%u, StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
2297 		      CmdSN, ExpStatSN, conn->StatSN, conn->sess->ExpCmdSN,
2298 		      conn->sess->MaxCmdSN);
2299 
2300 	if (ExpStatSN != conn->StatSN) {
2301 #if 0
2302 		SPDK_ERRLOG("StatSN(%u) error\n", ExpStatSN);
2303 		return -1;
2304 #else
2305 		/* StarPort have a bug */
2306 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "StatSN(%u) rewound\n", ExpStatSN);
2307 		conn->StatSN = ExpStatSN;
2308 #endif
2309 	}
2310 
2311 	if (F_bit && C_bit) {
2312 		SPDK_ERRLOG("final and continue\n");
2313 		return -1;
2314 	}
2315 
2316 	/*
2317 	 * If this is the first text op in a sequence, save the ITT so we can
2318 	 * compare it against the ITT for subsequent ops in the same sequence.
2319 	 * If a subsequent text op in same sequence has a different ITT, reject
2320 	 * that PDU.
2321 	 */
2322 	if (conn->sess->current_text_itt == 0xffffffffU) {
2323 		conn->sess->current_text_itt = task_tag;
2324 	} else if (conn->sess->current_text_itt != task_tag) {
2325 		SPDK_ERRLOG("The correct itt is %u, and the current itt is %u...\n",
2326 			    conn->sess->current_text_itt, task_tag);
2327 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
2328 	}
2329 
2330 	/* store incoming parameters */
2331 	rc = spdk_iscsi_parse_params(&params, pdu->data, pdu->data_segment_len,
2332 				     C_bit, &conn->partial_text_parameter);
2333 	if (rc < 0) {
2334 		SPDK_ERRLOG("iscsi_parse_params() failed\n");
2335 		spdk_iscsi_param_free(params);
2336 		return -1;
2337 	}
2338 
2339 	data = calloc(1, alloc_len);
2340 	if (!data) {
2341 		SPDK_ERRLOG("calloc() failed for data segment\n");
2342 		spdk_iscsi_param_free(params);
2343 		return -ENOMEM;
2344 	}
2345 
2346 	/* negotiate parameters */
2347 	data_len = spdk_iscsi_negotiate_params(conn, params_p,
2348 					       data, alloc_len, data_len);
2349 	if (data_len < 0) {
2350 		SPDK_ERRLOG("spdk_iscsi_negotiate_params() failed\n");
2351 		spdk_iscsi_param_free(*params_p);
2352 		free(data);
2353 		return -1;
2354 	}
2355 
2356 	/* sendtargets is special case */
2357 	val = spdk_iscsi_param_get_val(*params_p, "SendTargets");
2358 	if (val != NULL) {
2359 		if (spdk_iscsi_param_eq_val(conn->sess->params,
2360 					    "SessionType", "Discovery")) {
2361 			if (strcasecmp(val, "") == 0) {
2362 				val = "ALL";
2363 			}
2364 
2365 			data_len = spdk_iscsi_send_tgts(conn,
2366 							conn->initiator_name,
2367 							conn->initiator_addr,
2368 							val, data, alloc_len,
2369 							data_len);
2370 		} else {
2371 			if (strcasecmp(val, "") == 0) {
2372 				val = conn->target->name;
2373 			}
2374 
2375 			if (strcasecmp(val, "ALL") == 0) {
2376 				/* not in discovery session */
2377 				data_len = iscsi_append_text(conn,
2378 							     "SendTargets",
2379 							     "Reject", data,
2380 							     alloc_len, data_len);
2381 			} else {
2382 				data_len = spdk_iscsi_send_tgts(conn,
2383 								conn->initiator_name,
2384 								conn->initiator_addr,
2385 								val, data, alloc_len,
2386 								data_len);
2387 			}
2388 		}
2389 	} else {
2390 		if (spdk_iscsi_param_eq_val(conn->sess->params, "SessionType", "Discovery")) {
2391 			spdk_iscsi_param_free(*params_p);
2392 			free(data);
2393 			return SPDK_ISCSI_CONNECTION_FATAL;
2394 		}
2395 	}
2396 
2397 	SPDK_LOGDUMP(SPDK_LOG_ISCSI, "Negotiated Params", data, data_len);
2398 
2399 	/* response PDU */
2400 	rsp_pdu = spdk_get_pdu();
2401 	if (rsp_pdu == NULL) {
2402 		spdk_iscsi_param_free(*params_p);
2403 		free(data);
2404 		return SPDK_ISCSI_CONNECTION_FATAL;
2405 	}
2406 	rsph = (struct iscsi_bhs_text_resp *)&rsp_pdu->bhs;
2407 
2408 	rsp_pdu->data = data;
2409 	rsph->opcode = ISCSI_OP_TEXT_RSP;
2410 
2411 	if (F_bit) {
2412 		rsph->flags |= ISCSI_FLAG_FINAL;
2413 	}
2414 
2415 	if (C_bit) {
2416 		rsph->flags |= ISCSI_TEXT_CONTINUE;
2417 	}
2418 
2419 	DSET24(rsph->data_segment_len, data_len);
2420 	to_be64(&rsph->lun, lun);
2421 	to_be32(&rsph->itt, task_tag);
2422 
2423 	if (F_bit) {
2424 		rsph->ttt = 0xffffffffU;
2425 		conn->sess->current_text_itt = 0xffffffffU;
2426 	} else {
2427 		to_be32(&rsph->ttt, 1 + conn->id);
2428 	}
2429 
2430 	to_be32(&rsph->stat_sn, conn->StatSN);
2431 	conn->StatSN++;
2432 
2433 	if (reqh->immediate == 0) {
2434 		conn->sess->MaxCmdSN++;
2435 	}
2436 
2437 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
2438 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
2439 
2440 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
2441 
2442 	/* update internal variables */
2443 	rc = spdk_iscsi_copy_param2var(conn);
2444 	if (rc < 0) {
2445 		SPDK_ERRLOG("spdk_iscsi_copy_param2var() failed\n");
2446 		spdk_iscsi_param_free(*params_p);
2447 		return -1;
2448 	}
2449 
2450 	/* check value */
2451 	rc = iscsi_check_values(conn);
2452 	if (rc < 0) {
2453 		SPDK_ERRLOG("iscsi_check_values() failed\n");
2454 		spdk_iscsi_param_free(*params_p);
2455 		return -1;
2456 	}
2457 
2458 	spdk_iscsi_param_free(*params_p);
2459 	return 0;
2460 }
2461 
2462 static int
2463 iscsi_op_logout(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2464 {
2465 	struct spdk_iscsi_pdu *rsp_pdu;
2466 	uint32_t task_tag;
2467 	uint32_t CmdSN;
2468 	uint32_t ExpStatSN;
2469 	int response;
2470 	struct iscsi_bhs_logout_req *reqh;
2471 	struct iscsi_bhs_logout_resp *rsph;
2472 	uint16_t cid;
2473 
2474 	reqh = (struct iscsi_bhs_logout_req *)&pdu->bhs;
2475 
2476 	cid = from_be16(&reqh->cid);
2477 	task_tag = from_be32(&reqh->itt);
2478 	CmdSN = from_be32(&reqh->cmd_sn);
2479 	pdu->cmd_sn = CmdSN;
2480 	ExpStatSN = from_be32(&reqh->exp_stat_sn);
2481 
2482 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "reason=%d, ITT=%x, cid=%d\n",
2483 		      reqh->reason, task_tag, cid);
2484 
2485 	if (reqh->reason != 0 && conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
2486 		SPDK_ERRLOG("only logout with close the session reason can be in discovery session");
2487 		return SPDK_ISCSI_CONNECTION_FATAL;
2488 	}
2489 
2490 	if (conn->sess != NULL) {
2491 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI,
2492 			      "CmdSN=%u, ExpStatSN=%u, StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
2493 			      CmdSN, ExpStatSN, conn->StatSN,
2494 			      conn->sess->ExpCmdSN, conn->sess->MaxCmdSN);
2495 
2496 		if (CmdSN != conn->sess->ExpCmdSN) {
2497 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "CmdSN(%u) might have dropped\n", CmdSN);
2498 			/* ignore error */
2499 		}
2500 	} else {
2501 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "CmdSN=%u, ExpStatSN=%u, StatSN=%u\n",
2502 			      CmdSN, ExpStatSN, conn->StatSN);
2503 	}
2504 
2505 	if (ExpStatSN != conn->StatSN) {
2506 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "StatSN(%u/%u) might have dropped\n",
2507 			      ExpStatSN, conn->StatSN);
2508 		/* ignore error */
2509 	}
2510 
2511 	if (conn->id == cid) {
2512 		/* connection or session closed successfully */
2513 		response = 0;
2514 		spdk_iscsi_conn_logout(conn);
2515 	} else {
2516 		response = 1;
2517 	}
2518 
2519 	/* response PDU */
2520 	rsp_pdu = spdk_get_pdu();
2521 	if (rsp_pdu == NULL) {
2522 		return SPDK_ISCSI_CONNECTION_FATAL;
2523 	}
2524 	rsph = (struct iscsi_bhs_logout_resp *)&rsp_pdu->bhs;
2525 	rsp_pdu->data = NULL;
2526 	rsph->opcode = ISCSI_OP_LOGOUT_RSP;
2527 	rsph->flags |= 0x80; /* bit 0 must be 1 */
2528 	rsph->response = response;
2529 	DSET24(rsph->data_segment_len, 0);
2530 	to_be32(&rsph->itt, task_tag);
2531 
2532 	if (conn->sess != NULL) {
2533 		to_be32(&rsph->stat_sn, conn->StatSN);
2534 		conn->StatSN++;
2535 
2536 		if (conn->sess->connections == 1) {
2537 			conn->sess->MaxCmdSN++;
2538 		}
2539 
2540 		to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
2541 		to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
2542 	} else {
2543 		to_be32(&rsph->stat_sn, conn->StatSN);
2544 		conn->StatSN++;
2545 		to_be32(&rsph->exp_cmd_sn, CmdSN);
2546 		to_be32(&rsph->max_cmd_sn, CmdSN);
2547 	}
2548 
2549 	rsph->time_2_wait = 0;
2550 	rsph->time_2_retain = 0;
2551 
2552 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
2553 
2554 	if (conn->sess == NULL) {
2555 		/*
2556 		 * login failed but initiator still sent a logout rather than
2557 		 *  just closing the TCP connection.
2558 		 */
2559 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Logout(login failed) from %s (%s) on"
2560 			      " (%s:%s,%d)\n",
2561 			      conn->initiator_name, conn->initiator_addr,
2562 			      conn->portal_host, conn->portal_port, conn->pg_tag);
2563 	} else if (spdk_iscsi_param_eq_val(conn->sess->params, "SessionType", "Normal")) {
2564 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Logout from %s (%s) on %s tgt_node%d"
2565 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2566 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2567 			      conn->initiator_name, conn->initiator_addr,
2568 			      conn->target->name, conn->target->num,
2569 			      conn->portal_host, conn->portal_port, conn->pg_tag,
2570 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2571 			      (spdk_iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2572 			       ? "on" : "off"),
2573 			      (spdk_iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2574 			       ? "on" : "off"));
2575 	} else {
2576 		/* discovery session */
2577 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Logout(discovery) from %s (%s) on"
2578 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2579 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2580 			      conn->initiator_name, conn->initiator_addr,
2581 			      conn->portal_host, conn->portal_port, conn->pg_tag,
2582 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2583 			      (spdk_iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2584 			       ? "on" : "off"),
2585 			      (spdk_iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2586 			       ? "on" : "off"));
2587 	}
2588 
2589 	return 0;
2590 }
2591 
2592 /* This function returns the spdk_scsi_task by searching the snack list via
2593  * task transfertag and the pdu's opcode
2594  */
2595 static struct spdk_iscsi_task *
2596 get_scsi_task_from_ttt(struct spdk_iscsi_conn *conn, uint32_t transfer_tag)
2597 {
2598 	struct spdk_iscsi_pdu *pdu;
2599 	struct iscsi_bhs_data_in *datain_bhs;
2600 
2601 	TAILQ_FOREACH(pdu, &conn->snack_pdu_list, tailq) {
2602 		if (pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
2603 			datain_bhs = (struct iscsi_bhs_data_in *)&pdu->bhs;
2604 			if (from_be32(&datain_bhs->ttt) == transfer_tag) {
2605 				return pdu->task;
2606 			}
2607 		}
2608 	}
2609 
2610 	return NULL;
2611 }
2612 
2613 /* This function returns the spdk_scsi_task by searching the snack list via
2614  * initiator task tag and the pdu's opcode
2615  */
2616 static struct spdk_iscsi_task *
2617 get_scsi_task_from_itt(struct spdk_iscsi_conn *conn,
2618 		       uint32_t task_tag, enum iscsi_op opcode)
2619 {
2620 	struct spdk_iscsi_pdu *pdu;
2621 
2622 	TAILQ_FOREACH(pdu, &conn->snack_pdu_list, tailq) {
2623 		if (pdu->bhs.opcode == opcode &&
2624 		    pdu->task != NULL &&
2625 		    pdu->task->tag == task_tag) {
2626 			return pdu->task;
2627 		}
2628 	}
2629 
2630 	return NULL;
2631 }
2632 
2633 static int
2634 iscsi_send_datain(struct spdk_iscsi_conn *conn,
2635 		  struct spdk_iscsi_task *task, int datain_flag,
2636 		  int residual_len, int offset, int DataSN, int len)
2637 {
2638 	struct spdk_iscsi_pdu *rsp_pdu;
2639 	struct iscsi_bhs_data_in *rsph;
2640 	uint32_t task_tag;
2641 	uint32_t transfer_tag;
2642 	int F_bit, U_bit, O_bit, S_bit;
2643 	struct spdk_iscsi_task *primary;
2644 
2645 	primary = spdk_iscsi_task_get_primary(task);
2646 
2647 	/* DATA PDU */
2648 	rsp_pdu = spdk_get_pdu();
2649 	rsph = (struct iscsi_bhs_data_in *)&rsp_pdu->bhs;
2650 	rsp_pdu->data = task->scsi.iovs[0].iov_base + offset;
2651 	rsp_pdu->data_buf_len = task->scsi.iovs[0].iov_len - offset;
2652 	rsp_pdu->data_from_mempool = true;
2653 
2654 	task_tag = task->tag;
2655 	transfer_tag = 0xffffffffU;
2656 
2657 	F_bit = datain_flag & ISCSI_FLAG_FINAL;
2658 	O_bit = datain_flag & ISCSI_DATAIN_OVERFLOW;
2659 	U_bit = datain_flag & ISCSI_DATAIN_UNDERFLOW;
2660 	S_bit = datain_flag & ISCSI_DATAIN_STATUS;
2661 
2662 	/*
2663 	 * we need to hold onto this task/cmd because until the
2664 	 * PDU has been written out
2665 	 */
2666 	rsp_pdu->task = task;
2667 	task->scsi.ref++;
2668 
2669 	rsph->opcode = ISCSI_OP_SCSI_DATAIN;
2670 
2671 	if (F_bit) {
2672 		rsph->flags |= ISCSI_FLAG_FINAL;
2673 	}
2674 
2675 	/* we leave the A_bit clear */
2676 
2677 	if (F_bit && S_bit)  {
2678 		if (O_bit) {
2679 			rsph->flags |= ISCSI_DATAIN_OVERFLOW;
2680 		}
2681 
2682 		if (U_bit) {
2683 			rsph->flags |= ISCSI_DATAIN_UNDERFLOW;
2684 		}
2685 	}
2686 
2687 	if (S_bit) {
2688 		rsph->flags |= ISCSI_DATAIN_STATUS;
2689 		rsph->status = task->scsi.status;
2690 	}
2691 
2692 	DSET24(rsph->data_segment_len, len);
2693 
2694 	to_be32(&rsph->itt, task_tag);
2695 	to_be32(&rsph->ttt, transfer_tag);
2696 
2697 	if (S_bit) {
2698 		to_be32(&rsph->stat_sn, conn->StatSN);
2699 		conn->StatSN++;
2700 	}
2701 
2702 	if (F_bit && S_bit && !spdk_iscsi_task_is_immediate(primary)) {
2703 		conn->sess->MaxCmdSN++;
2704 	}
2705 
2706 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
2707 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
2708 
2709 	to_be32(&rsph->data_sn, DataSN);
2710 
2711 	if (conn->sess->ErrorRecoveryLevel >= 1) {
2712 		primary->datain_datasn = DataSN;
2713 	}
2714 	DataSN++;
2715 
2716 	if (task->parent) {
2717 		offset += primary->scsi.data_transferred;
2718 	}
2719 	to_be32(&rsph->buffer_offset, (uint32_t)offset);
2720 
2721 	if (F_bit && S_bit) {
2722 		to_be32(&rsph->res_cnt, residual_len);
2723 	}
2724 
2725 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
2726 
2727 	return DataSN;
2728 }
2729 
2730 static int
2731 iscsi_transfer_in(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
2732 {
2733 	uint32_t DataSN;
2734 	int transfer_len;
2735 	int data_len;
2736 	int segment_len;
2737 	int offset;
2738 	int residual_len = 0;
2739 	int sent_status;
2740 	int len;
2741 	int datain_flag = 0;
2742 	int datain_seq_cnt;
2743 	int i;
2744 	int sequence_end;
2745 	struct spdk_iscsi_task *primary;
2746 
2747 	primary = spdk_iscsi_task_get_primary(task);
2748 	segment_len = conn->MaxRecvDataSegmentLength;
2749 	data_len = task->scsi.data_transferred;
2750 	transfer_len = task->scsi.length;
2751 
2752 	if (task->scsi.status != SPDK_SCSI_STATUS_GOOD) {
2753 		if (task != primary) {
2754 			conn->data_in_cnt--;
2755 			/* Handle the case when primary task return success but the subtask failed */
2756 			if (primary->bytes_completed == primary->scsi.transfer_len &&
2757 			    primary->scsi.status == SPDK_SCSI_STATUS_GOOD) {
2758 				conn->data_in_cnt--;
2759 			}
2760 		} else {
2761 			/* handle the case that it is a primary task which has subtasks */
2762 			if (primary->scsi.transfer_len != primary->scsi.length) {
2763 				conn->data_in_cnt--;
2764 			}
2765 		}
2766 
2767 		return 0;
2768 	}
2769 
2770 	if (data_len < transfer_len) {
2771 		/* underflow */
2772 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Underflow %u/%u\n", data_len, transfer_len);
2773 		residual_len = transfer_len - data_len;
2774 		transfer_len = data_len;
2775 		datain_flag |= ISCSI_DATAIN_UNDERFLOW;
2776 	} else if (data_len > transfer_len) {
2777 		/* overflow */
2778 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Overflow %u/%u\n", data_len, transfer_len);
2779 		residual_len = data_len - transfer_len;
2780 		datain_flag |= ISCSI_DATAIN_OVERFLOW;
2781 	} else {
2782 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Transfer %u\n", transfer_len);
2783 		residual_len = 0;
2784 	}
2785 
2786 	DataSN = primary->datain_datasn;
2787 	sent_status = 0;
2788 
2789 	/* calculate the number of sequences for all data-in pdus */
2790 	datain_seq_cnt = 1 + ((transfer_len - 1) / (int)conn->sess->MaxBurstLength);
2791 	for (i = 0; i < datain_seq_cnt; i++) {
2792 		offset = i * conn->sess->MaxBurstLength;
2793 		sequence_end = DMIN32(((i + 1) * conn->sess->MaxBurstLength),
2794 				      transfer_len);
2795 
2796 		/* send data splitted by segment_len */
2797 		for (; offset < sequence_end; offset += segment_len) {
2798 			len = DMIN32(segment_len, (sequence_end - offset));
2799 
2800 			datain_flag &= ~ISCSI_FLAG_FINAL;
2801 			datain_flag &= ~ISCSI_DATAIN_STATUS;
2802 
2803 			if (offset + len == sequence_end) {
2804 				/* last PDU in a sequence */
2805 				datain_flag |= ISCSI_FLAG_FINAL;
2806 				if (task->scsi.sense_data_len == 0) {
2807 					/* The last pdu in all data-in pdus */
2808 					if ((offset + len) == transfer_len &&
2809 					    (primary->bytes_completed == primary->scsi.transfer_len)) {
2810 						datain_flag |= ISCSI_DATAIN_STATUS;
2811 						sent_status = 1;
2812 					}
2813 				}
2814 			}
2815 
2816 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Transfer=%d, Offset=%d, Len=%d\n",
2817 				      sequence_end, offset, len);
2818 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "StatSN=%u, DataSN=%u, Offset=%u, Len=%d\n",
2819 				      conn->StatSN, DataSN, offset, len);
2820 
2821 			DataSN = iscsi_send_datain(conn, task, datain_flag, residual_len,
2822 						   offset, DataSN, len);
2823 		}
2824 	}
2825 
2826 	if (task != primary) {
2827 		primary->scsi.data_transferred += task->scsi.data_transferred;
2828 	}
2829 	primary->datain_datasn = DataSN;
2830 
2831 	return sent_status;
2832 }
2833 
2834 /*
2835  *  This function compare the input pdu's bhs with the pdu's bhs associated by
2836  *  active_r2t_tasks and queued_r2t_tasks in a connection
2837  */
2838 static bool
2839 iscsi_compare_pdu_bhs_within_existed_r2t_tasks(struct spdk_iscsi_conn *conn,
2840 		struct spdk_iscsi_pdu *pdu)
2841 {
2842 	struct spdk_iscsi_task	*task;
2843 
2844 	TAILQ_FOREACH(task, &conn->active_r2t_tasks, link) {
2845 		if (!memcmp(&pdu->bhs, spdk_iscsi_task_get_bhs(task), ISCSI_BHS_LEN)) {
2846 			return true;
2847 		}
2848 	}
2849 
2850 	TAILQ_FOREACH(task, &conn->queued_r2t_tasks, link) {
2851 		if (!memcmp(&pdu->bhs, spdk_iscsi_task_get_bhs(task), ISCSI_BHS_LEN)) {
2852 			return true;
2853 		}
2854 	}
2855 
2856 	return false;
2857 }
2858 
2859 static void
2860 iscsi_queue_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
2861 {
2862 	spdk_trace_record(TRACE_ISCSI_TASK_QUEUE, conn->id, task->scsi.length,
2863 			  (uintptr_t)task, (uintptr_t)task->pdu);
2864 	task->is_queued = true;
2865 	spdk_scsi_dev_queue_task(conn->dev, &task->scsi);
2866 }
2867 
2868 static void
2869 iscsi_queue_mgmt_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
2870 {
2871 	spdk_scsi_dev_queue_mgmt_task(conn->dev, &task->scsi);
2872 }
2873 
2874 int spdk_iscsi_conn_handle_queued_datain_tasks(struct spdk_iscsi_conn *conn)
2875 {
2876 	struct spdk_iscsi_task *task;
2877 
2878 	while (!TAILQ_EMPTY(&conn->queued_datain_tasks) &&
2879 	       conn->data_in_cnt < MAX_LARGE_DATAIN_PER_CONNECTION) {
2880 		task = TAILQ_FIRST(&conn->queued_datain_tasks);
2881 		assert(task->current_datain_offset <= task->scsi.transfer_len);
2882 
2883 		if (task->current_datain_offset == 0) {
2884 			task->scsi.lun = spdk_scsi_dev_get_lun(conn->dev, task->lun_id);
2885 			if (task->scsi.lun == NULL) {
2886 				TAILQ_REMOVE(&conn->queued_datain_tasks, task, link);
2887 				spdk_scsi_task_process_null_lun(&task->scsi);
2888 				spdk_iscsi_task_cpl(&task->scsi);
2889 				return 0;
2890 			}
2891 			task->current_datain_offset = task->scsi.length;
2892 			conn->data_in_cnt++;
2893 			iscsi_queue_task(conn, task);
2894 			continue;
2895 		}
2896 		if (task->current_datain_offset < task->scsi.transfer_len) {
2897 			struct spdk_iscsi_task *subtask;
2898 			uint32_t remaining_size = 0;
2899 
2900 			remaining_size = task->scsi.transfer_len - task->current_datain_offset;
2901 			subtask = spdk_iscsi_task_get(conn, task, spdk_iscsi_task_cpl);
2902 			assert(subtask != NULL);
2903 			subtask->scsi.offset = task->current_datain_offset;
2904 			subtask->scsi.length = DMIN32(SPDK_BDEV_LARGE_BUF_MAX_SIZE, remaining_size);
2905 			spdk_scsi_task_set_data(&subtask->scsi, NULL, 0);
2906 			task->current_datain_offset += subtask->scsi.length;
2907 			conn->data_in_cnt++;
2908 
2909 			task->scsi.lun = spdk_scsi_dev_get_lun(conn->dev, task->lun_id);
2910 			if (task->scsi.lun == NULL) {
2911 				/* Remove the primary task from the list if this is the last subtask */
2912 				if (task->current_datain_offset == task->scsi.transfer_len) {
2913 					TAILQ_REMOVE(&conn->queued_datain_tasks, task, link);
2914 				}
2915 				subtask->scsi.transfer_len = subtask->scsi.length;
2916 				spdk_scsi_task_process_null_lun(&subtask->scsi);
2917 				spdk_iscsi_task_cpl(&subtask->scsi);
2918 				return 0;
2919 			}
2920 
2921 			iscsi_queue_task(conn, subtask);
2922 		}
2923 		if (task->current_datain_offset == task->scsi.transfer_len) {
2924 			TAILQ_REMOVE(&conn->queued_datain_tasks, task, link);
2925 		}
2926 	}
2927 	return 0;
2928 }
2929 
2930 static int
2931 iscsi_op_scsi_read(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
2932 {
2933 	int32_t remaining_size;
2934 
2935 	TAILQ_INIT(&task->subtask_list);
2936 	task->scsi.dxfer_dir = SPDK_SCSI_DIR_FROM_DEV;
2937 	task->parent = NULL;
2938 	task->scsi.offset = 0;
2939 	task->scsi.length = DMIN32(SPDK_BDEV_LARGE_BUF_MAX_SIZE, task->scsi.transfer_len);
2940 	spdk_scsi_task_set_data(&task->scsi, NULL, 0);
2941 
2942 	remaining_size = task->scsi.transfer_len - task->scsi.length;
2943 	task->current_datain_offset = 0;
2944 
2945 	if (remaining_size == 0) {
2946 		iscsi_queue_task(conn, task);
2947 		return 0;
2948 	}
2949 
2950 	TAILQ_INSERT_TAIL(&conn->queued_datain_tasks, task, link);
2951 
2952 	return spdk_iscsi_conn_handle_queued_datain_tasks(conn);
2953 }
2954 
2955 static int
2956 iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2957 {
2958 	struct spdk_iscsi_task	*task;
2959 	struct spdk_scsi_dev	*dev;
2960 	uint8_t *cdb;
2961 	uint64_t lun;
2962 	uint32_t task_tag;
2963 	uint32_t transfer_len;
2964 	uint32_t scsi_data_len;
2965 	int F_bit, R_bit, W_bit;
2966 	int lun_i, rc;
2967 	struct iscsi_bhs_scsi_req *reqh;
2968 
2969 	if (conn->sess->session_type != SESSION_TYPE_NORMAL) {
2970 		SPDK_ERRLOG("ISCSI_OP_SCSI not allowed in discovery and invalid session\n");
2971 		return SPDK_ISCSI_CONNECTION_FATAL;
2972 	}
2973 
2974 	reqh = (struct iscsi_bhs_scsi_req *)&pdu->bhs;
2975 
2976 	F_bit = reqh->final_bit;
2977 	R_bit = reqh->read_bit;
2978 	W_bit = reqh->write_bit;
2979 	lun = from_be64(&reqh->lun);
2980 	task_tag = from_be32(&reqh->itt);
2981 	transfer_len = from_be32(&reqh->expected_data_xfer_len);
2982 	cdb = reqh->cdb;
2983 
2984 	SPDK_LOGDUMP(SPDK_LOG_ISCSI, "CDB", cdb, 16);
2985 
2986 	task = spdk_iscsi_task_get(conn, NULL, spdk_iscsi_task_cpl);
2987 	if (!task) {
2988 		SPDK_ERRLOG("Unable to acquire task\n");
2989 		return SPDK_ISCSI_CONNECTION_FATAL;
2990 	}
2991 
2992 	spdk_iscsi_task_associate_pdu(task, pdu);
2993 	lun_i = spdk_scsi_lun_id_fmt_to_int(lun);
2994 	task->lun_id = lun_i;
2995 	dev = conn->dev;
2996 	task->scsi.lun = spdk_scsi_dev_get_lun(dev, lun_i);
2997 
2998 	if ((R_bit != 0) && (W_bit != 0)) {
2999 		SPDK_ERRLOG("Bidirectional CDB is not supported\n");
3000 		spdk_iscsi_task_put(task);
3001 		return SPDK_ISCSI_CONNECTION_FATAL;
3002 	}
3003 
3004 	task->scsi.cdb = cdb;
3005 	task->tag = task_tag;
3006 	task->scsi.transfer_len = transfer_len;
3007 	task->scsi.target_port = conn->target_port;
3008 	task->scsi.initiator_port = conn->initiator_port;
3009 	task->parent = NULL;
3010 	task->rsp_scsi_status = SPDK_SCSI_STATUS_GOOD;
3011 
3012 	if (task->scsi.lun == NULL) {
3013 		spdk_scsi_task_process_null_lun(&task->scsi);
3014 		spdk_iscsi_task_cpl(&task->scsi);
3015 		return 0;
3016 	}
3017 
3018 	/* no bi-directional support */
3019 	if (R_bit) {
3020 		return iscsi_op_scsi_read(conn, task);
3021 	} else if (W_bit) {
3022 		task->scsi.dxfer_dir = SPDK_SCSI_DIR_TO_DEV;
3023 
3024 		if ((conn->sess->ErrorRecoveryLevel >= 1) &&
3025 		    (iscsi_compare_pdu_bhs_within_existed_r2t_tasks(conn, pdu))) {
3026 			spdk_iscsi_task_response(conn, task);
3027 			spdk_iscsi_task_put(task);
3028 			return 0;
3029 		}
3030 
3031 		if (pdu->data_segment_len > transfer_len) {
3032 			SPDK_ERRLOG("data segment len(=%d) > task transfer len(=%d)\n",
3033 				    (int)pdu->data_segment_len, transfer_len);
3034 			spdk_iscsi_task_put(task);
3035 			return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3036 		}
3037 
3038 		/* check the ImmediateData and also pdu->data_segment_len */
3039 		if ((!conn->sess->ImmediateData && (pdu->data_segment_len > 0)) ||
3040 		    (pdu->data_segment_len > conn->sess->FirstBurstLength)) {
3041 			spdk_iscsi_task_put(task);
3042 			return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3043 		}
3044 
3045 		if (spdk_likely(!pdu->dif_insert_or_strip)) {
3046 			scsi_data_len = pdu->data_segment_len;
3047 		} else {
3048 			scsi_data_len = pdu->data_buf_len;
3049 		}
3050 
3051 		if (F_bit && pdu->data_segment_len < transfer_len) {
3052 			/* needs R2T */
3053 			rc = add_transfer_task(conn, task);
3054 			if (rc < 0) {
3055 				SPDK_ERRLOG("add_transfer_task() failed\n");
3056 				spdk_iscsi_task_put(task);
3057 				return SPDK_ISCSI_CONNECTION_FATAL;
3058 			}
3059 
3060 			/* Non-immediate writes */
3061 			if (pdu->data_segment_len == 0) {
3062 				return 0;
3063 			} else {
3064 				/* we are doing the first partial write task */
3065 				task->scsi.ref++;
3066 				spdk_scsi_task_set_data(&task->scsi, pdu->data, scsi_data_len);
3067 				task->scsi.length = pdu->data_segment_len;
3068 			}
3069 		}
3070 
3071 		if (pdu->data_segment_len == transfer_len) {
3072 			/* we are doing small writes with no R2T */
3073 			spdk_scsi_task_set_data(&task->scsi, pdu->data, scsi_data_len);
3074 			task->scsi.length = transfer_len;
3075 		}
3076 	} else {
3077 		/* neither R nor W bit set */
3078 		task->scsi.dxfer_dir = SPDK_SCSI_DIR_NONE;
3079 		if (transfer_len > 0) {
3080 			spdk_iscsi_task_put(task);
3081 			SPDK_ERRLOG("Reject scsi cmd with EDTL > 0 but (R | W) == 0\n");
3082 			return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_PDU_FIELD);
3083 		}
3084 	}
3085 
3086 	iscsi_queue_task(conn, task);
3087 	return 0;
3088 }
3089 
3090 static void
3091 abort_transfer_task_in_task_mgmt_resp(struct spdk_iscsi_conn *conn,
3092 				      struct spdk_iscsi_task *task)
3093 {
3094 	struct spdk_iscsi_pdu *pdu;
3095 
3096 	pdu = spdk_iscsi_task_get_pdu(task);
3097 
3098 	switch (task->scsi.function) {
3099 	/* abort task identified by Reference Task Tag field */
3100 	case ISCSI_TASK_FUNC_ABORT_TASK:
3101 		spdk_del_transfer_task(conn, task->scsi.abort_id);
3102 		break;
3103 
3104 	/* abort all tasks issued via this session on the LUN */
3105 	case ISCSI_TASK_FUNC_ABORT_TASK_SET:
3106 		spdk_clear_all_transfer_task(conn, task->scsi.lun, pdu);
3107 		break;
3108 
3109 	case ISCSI_TASK_FUNC_LOGICAL_UNIT_RESET:
3110 		spdk_clear_all_transfer_task(conn, task->scsi.lun, pdu);
3111 		break;
3112 	}
3113 }
3114 
3115 void
3116 spdk_iscsi_task_mgmt_response(struct spdk_iscsi_conn *conn,
3117 			      struct spdk_iscsi_task *task)
3118 {
3119 	struct spdk_iscsi_pdu *rsp_pdu;
3120 	struct iscsi_bhs_task_req *reqh;
3121 	struct iscsi_bhs_task_resp *rsph;
3122 
3123 	if (task->pdu == NULL) {
3124 		/*
3125 		 * This was an internally generated task management command,
3126 		 *  usually from LUN cleanup when a connection closes.
3127 		 */
3128 		return;
3129 	}
3130 
3131 	reqh = (struct iscsi_bhs_task_req *)&task->pdu->bhs;
3132 	/* response PDU */
3133 	rsp_pdu = spdk_get_pdu();
3134 	rsph = (struct iscsi_bhs_task_resp *)&rsp_pdu->bhs;
3135 	rsph->opcode = ISCSI_OP_TASK_RSP;
3136 	rsph->flags |= 0x80; /* bit 0 default to 1 */
3137 	switch (task->scsi.response) {
3138 	case SPDK_SCSI_TASK_MGMT_RESP_COMPLETE:
3139 		abort_transfer_task_in_task_mgmt_resp(conn, task);
3140 		rsph->response = ISCSI_TASK_FUNC_RESP_COMPLETE;
3141 		break;
3142 	case SPDK_SCSI_TASK_MGMT_RESP_SUCCESS:
3143 		abort_transfer_task_in_task_mgmt_resp(conn, task);
3144 		rsph->response = ISCSI_TASK_FUNC_RESP_COMPLETE;
3145 		break;
3146 	case SPDK_SCSI_TASK_MGMT_RESP_REJECT:
3147 		rsph->response = ISCSI_TASK_FUNC_REJECTED;
3148 		break;
3149 	case SPDK_SCSI_TASK_MGMT_RESP_INVALID_LUN:
3150 		rsph->response = ISCSI_TASK_FUNC_RESP_LUN_NOT_EXIST;
3151 		break;
3152 	case SPDK_SCSI_TASK_MGMT_RESP_TARGET_FAILURE:
3153 		rsph->response = ISCSI_TASK_FUNC_REJECTED;
3154 		break;
3155 	case SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED:
3156 		rsph->response = ISCSI_TASK_FUNC_RESP_FUNC_NOT_SUPPORTED;
3157 		break;
3158 	}
3159 	rsph->itt = reqh->itt;
3160 
3161 	to_be32(&rsph->stat_sn, conn->StatSN);
3162 	conn->StatSN++;
3163 
3164 	if (reqh->immediate == 0) {
3165 		conn->sess->MaxCmdSN++;
3166 	}
3167 
3168 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
3169 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
3170 
3171 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
3172 }
3173 
3174 void spdk_iscsi_task_response(struct spdk_iscsi_conn *conn,
3175 			      struct spdk_iscsi_task *task)
3176 {
3177 	struct spdk_iscsi_pdu *rsp_pdu;
3178 	struct iscsi_bhs_scsi_resp *rsph;
3179 	uint32_t task_tag;
3180 	uint32_t transfer_len;
3181 	size_t residual_len;
3182 	size_t data_len;
3183 	int O_bit, U_bit;
3184 	int rc;
3185 	struct spdk_iscsi_task *primary;
3186 
3187 	primary = spdk_iscsi_task_get_primary(task);
3188 
3189 	transfer_len = primary->scsi.transfer_len;
3190 	task_tag = task->tag;
3191 
3192 	/* transfer data from logical unit */
3193 	/* (direction is view of initiator side) */
3194 	if (spdk_iscsi_task_is_read(primary)) {
3195 		rc = iscsi_transfer_in(conn, task);
3196 		if (rc > 0) {
3197 			/* sent status by last DATAIN PDU */
3198 			return;
3199 		}
3200 
3201 		if (primary->bytes_completed != primary->scsi.transfer_len) {
3202 			return;
3203 		}
3204 	}
3205 
3206 	O_bit = U_bit = 0;
3207 	residual_len = 0;
3208 	data_len = primary->scsi.data_transferred;
3209 
3210 	if ((transfer_len != 0) &&
3211 	    (task->scsi.status == SPDK_SCSI_STATUS_GOOD)) {
3212 		if (data_len < transfer_len) {
3213 			/* underflow */
3214 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Underflow %zu/%u\n", data_len, transfer_len);
3215 			residual_len = transfer_len - data_len;
3216 			U_bit = 1;
3217 		} else if (data_len > transfer_len) {
3218 			/* overflow */
3219 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Overflow %zu/%u\n", data_len, transfer_len);
3220 			residual_len = data_len - transfer_len;
3221 			O_bit = 1;
3222 		} else {
3223 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Transfer %u\n", transfer_len);
3224 		}
3225 	}
3226 
3227 	/* response PDU */
3228 	rsp_pdu = spdk_get_pdu();
3229 	assert(rsp_pdu != NULL);
3230 	rsph = (struct iscsi_bhs_scsi_resp *)&rsp_pdu->bhs;
3231 	assert(task->scsi.sense_data_len <= sizeof(rsp_pdu->sense.data));
3232 	memcpy(rsp_pdu->sense.data, task->scsi.sense_data, task->scsi.sense_data_len);
3233 	to_be16(&rsp_pdu->sense.length, task->scsi.sense_data_len);
3234 	rsp_pdu->data = (uint8_t *)&rsp_pdu->sense;
3235 	rsp_pdu->data_from_mempool = true;
3236 
3237 	/*
3238 	 * we need to hold onto this task/cmd because until the
3239 	 * PDU has been written out
3240 	 */
3241 	rsp_pdu->task = task;
3242 	task->scsi.ref++;
3243 
3244 	rsph->opcode = ISCSI_OP_SCSI_RSP;
3245 	rsph->flags |= 0x80; /* bit 0 is default to 1 */
3246 
3247 	if (O_bit) {
3248 		rsph->flags |= ISCSI_SCSI_OVERFLOW;
3249 	}
3250 
3251 	if (U_bit) {
3252 		rsph->flags |= ISCSI_SCSI_UNDERFLOW;
3253 	}
3254 
3255 	rsph->status = task->scsi.status;
3256 	if (task->scsi.sense_data_len) {
3257 		/* SenseLength (2 bytes) + SenseData  */
3258 		DSET24(rsph->data_segment_len, 2 + task->scsi.sense_data_len);
3259 	}
3260 	to_be32(&rsph->itt, task_tag);
3261 
3262 	to_be32(&rsph->stat_sn, conn->StatSN);
3263 	conn->StatSN++;
3264 
3265 	if (!spdk_iscsi_task_is_immediate(primary)) {
3266 		conn->sess->MaxCmdSN++;
3267 	}
3268 
3269 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
3270 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
3271 
3272 	to_be32(&rsph->bi_read_res_cnt, 0);
3273 	to_be32(&rsph->res_cnt, residual_len);
3274 
3275 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
3276 }
3277 
3278 static struct spdk_iscsi_task *
3279 get_transfer_task(struct spdk_iscsi_conn *conn, uint32_t transfer_tag)
3280 {
3281 	int i;
3282 
3283 	for (i = 0; i < conn->pending_r2t; i++) {
3284 		if (conn->outstanding_r2t_tasks[i]->ttt == transfer_tag) {
3285 			return (conn->outstanding_r2t_tasks[i]);
3286 		}
3287 	}
3288 
3289 	return NULL;
3290 }
3291 
3292 static int
3293 _iscsi_conn_abort_queued_datain_task(struct spdk_iscsi_conn *conn,
3294 				     struct spdk_iscsi_task *task)
3295 {
3296 	struct spdk_iscsi_task *subtask;
3297 	uint32_t remaining_size;
3298 
3299 	while (conn->data_in_cnt < MAX_LARGE_DATAIN_PER_CONNECTION) {
3300 		assert(task->current_datain_offset <= task->scsi.transfer_len);
3301 
3302 		/* If no IO is submitted yet, just abort the primary task. */
3303 		if (task->current_datain_offset == 0) {
3304 			TAILQ_REMOVE(&conn->queued_datain_tasks, task, link);
3305 			spdk_scsi_task_process_abort(&task->scsi);
3306 			spdk_iscsi_task_cpl(&task->scsi);
3307 			return 0;
3308 		}
3309 
3310 		/* If any IO is submitted already, abort all subtasks by repetition. */
3311 		if (task->current_datain_offset < task->scsi.transfer_len) {
3312 			remaining_size = task->scsi.transfer_len - task->current_datain_offset;
3313 			subtask = spdk_iscsi_task_get(conn, task, spdk_iscsi_task_cpl);
3314 			assert(subtask != NULL);
3315 			subtask->scsi.offset = task->current_datain_offset;
3316 			subtask->scsi.length = DMIN32(SPDK_BDEV_LARGE_BUF_MAX_SIZE, remaining_size);
3317 			spdk_scsi_task_set_data(&subtask->scsi, NULL, 0);
3318 			task->current_datain_offset += subtask->scsi.length;
3319 			conn->data_in_cnt++;
3320 
3321 			subtask->scsi.transfer_len = subtask->scsi.length;
3322 			spdk_scsi_task_process_abort(&subtask->scsi);
3323 			spdk_iscsi_task_cpl(&subtask->scsi);
3324 		}
3325 
3326 		/* Remove the primary task from the list if this is the last subtask */
3327 		if (task->current_datain_offset == task->scsi.transfer_len) {
3328 			TAILQ_REMOVE(&conn->queued_datain_tasks, task, link);
3329 			return 0;
3330 		}
3331 	}
3332 
3333 	return -1;
3334 }
3335 
3336 static int
3337 iscsi_conn_abort_queued_datain_task(struct spdk_iscsi_conn *conn,
3338 				    uint32_t ref_task_tag)
3339 {
3340 	struct spdk_iscsi_task *task;
3341 
3342 	TAILQ_FOREACH(task, &conn->queued_datain_tasks, link) {
3343 		if (task->tag == ref_task_tag) {
3344 			return _iscsi_conn_abort_queued_datain_task(conn, task);
3345 		}
3346 	}
3347 
3348 	return 0;
3349 }
3350 
3351 static int
3352 iscsi_conn_abort_queued_datain_tasks(struct spdk_iscsi_conn *conn,
3353 				     struct spdk_scsi_lun *lun,
3354 				     struct spdk_iscsi_pdu *pdu)
3355 {
3356 	struct spdk_iscsi_task *task, *task_tmp;
3357 	struct spdk_iscsi_pdu *pdu_tmp;
3358 	int rc;
3359 
3360 	TAILQ_FOREACH_SAFE(task, &conn->queued_datain_tasks, link, task_tmp) {
3361 		pdu_tmp = spdk_iscsi_task_get_pdu(task);
3362 		if ((lun == NULL || lun == task->scsi.lun) &&
3363 		    (pdu == NULL || (SN32_LT(pdu_tmp->cmd_sn, pdu->cmd_sn)))) {
3364 			rc = _iscsi_conn_abort_queued_datain_task(conn, task);
3365 			if (rc != 0) {
3366 				return rc;
3367 			}
3368 		}
3369 	}
3370 
3371 	return 0;
3372 }
3373 
3374 static int
3375 _iscsi_op_abort_task(void *arg)
3376 {
3377 	struct spdk_iscsi_task *task = arg;
3378 	int rc;
3379 
3380 	rc = iscsi_conn_abort_queued_datain_task(task->conn, task->scsi.abort_id);
3381 	if (rc != 0) {
3382 		return 1;
3383 	}
3384 
3385 	spdk_poller_unregister(&task->mgmt_poller);
3386 	iscsi_queue_mgmt_task(task->conn, task);
3387 	return 1;
3388 }
3389 
3390 static void
3391 iscsi_op_abort_task(struct spdk_iscsi_task *task, uint32_t ref_task_tag)
3392 {
3393 	task->scsi.abort_id = ref_task_tag;
3394 	task->scsi.function = SPDK_SCSI_TASK_FUNC_ABORT_TASK;
3395 	task->mgmt_poller = spdk_poller_register(_iscsi_op_abort_task, task, 10);
3396 }
3397 
3398 static int
3399 _iscsi_op_abort_task_set(void *arg)
3400 {
3401 	struct spdk_iscsi_task *task = arg;
3402 	int rc;
3403 
3404 	rc = iscsi_conn_abort_queued_datain_tasks(task->conn, task->scsi.lun,
3405 			task->pdu);
3406 	if (rc != 0) {
3407 		return 1;
3408 	}
3409 
3410 	spdk_poller_unregister(&task->mgmt_poller);
3411 	iscsi_queue_mgmt_task(task->conn, task);
3412 	return 1;
3413 }
3414 
3415 void
3416 spdk_iscsi_op_abort_task_set(struct spdk_iscsi_task *task, uint8_t function)
3417 {
3418 	task->scsi.function = function;
3419 	task->mgmt_poller = spdk_poller_register(_iscsi_op_abort_task_set, task, 10);
3420 }
3421 
3422 static int
3423 iscsi_op_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3424 {
3425 	struct iscsi_bhs_task_req *reqh;
3426 	uint64_t lun;
3427 	uint32_t task_tag;
3428 	uint32_t ref_task_tag;
3429 	uint8_t function;
3430 	int lun_i;
3431 	struct spdk_iscsi_task *task;
3432 	struct spdk_scsi_dev *dev;
3433 
3434 	if (conn->sess->session_type != SESSION_TYPE_NORMAL) {
3435 		SPDK_ERRLOG("ISCSI_OP_TASK not allowed in discovery and invalid session\n");
3436 		return SPDK_ISCSI_CONNECTION_FATAL;
3437 	}
3438 
3439 	reqh = (struct iscsi_bhs_task_req *)&pdu->bhs;
3440 	function = reqh->flags & ISCSI_TASK_FUNCTION_MASK;
3441 	lun = from_be64(&reqh->lun);
3442 	task_tag = from_be32(&reqh->itt);
3443 	ref_task_tag = from_be32(&reqh->ref_task_tag);
3444 
3445 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "I=%d, func=%d, ITT=%x, ref TT=%x, LUN=0x%16.16"PRIx64"\n",
3446 		      reqh->immediate, function, task_tag, ref_task_tag, lun);
3447 
3448 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
3449 		      conn->StatSN, conn->sess->ExpCmdSN, conn->sess->MaxCmdSN);
3450 
3451 	lun_i = spdk_scsi_lun_id_fmt_to_int(lun);
3452 	dev = conn->dev;
3453 
3454 	task = spdk_iscsi_task_get(conn, NULL, spdk_iscsi_task_mgmt_cpl);
3455 	if (!task) {
3456 		SPDK_ERRLOG("Unable to acquire task\n");
3457 		return SPDK_ISCSI_CONNECTION_FATAL;
3458 	}
3459 
3460 	spdk_iscsi_task_associate_pdu(task, pdu);
3461 	task->scsi.target_port = conn->target_port;
3462 	task->scsi.initiator_port = conn->initiator_port;
3463 	task->tag = task_tag;
3464 	task->scsi.lun = spdk_scsi_dev_get_lun(dev, lun_i);
3465 
3466 	if (task->scsi.lun == NULL) {
3467 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_INVALID_LUN;
3468 		spdk_iscsi_task_mgmt_response(conn, task);
3469 		spdk_iscsi_task_put(task);
3470 		return 0;
3471 	}
3472 
3473 	switch (function) {
3474 	/* abort task identified by Referenced Task Tag field */
3475 	case ISCSI_TASK_FUNC_ABORT_TASK:
3476 		SPDK_NOTICELOG("ABORT_TASK\n");
3477 
3478 		iscsi_op_abort_task(task, ref_task_tag);
3479 		return SPDK_SUCCESS;
3480 
3481 	/* abort all tasks issued via this session on the LUN */
3482 	case ISCSI_TASK_FUNC_ABORT_TASK_SET:
3483 		SPDK_NOTICELOG("ABORT_TASK_SET\n");
3484 
3485 		spdk_iscsi_op_abort_task_set(task, SPDK_SCSI_TASK_FUNC_ABORT_TASK_SET);
3486 		return SPDK_SUCCESS;
3487 
3488 	case ISCSI_TASK_FUNC_CLEAR_TASK_SET:
3489 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3490 		SPDK_NOTICELOG("CLEAR_TASK_SET (Unsupported)\n");
3491 		break;
3492 
3493 	case ISCSI_TASK_FUNC_CLEAR_ACA:
3494 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3495 		SPDK_NOTICELOG("CLEAR_ACA (Unsupported)\n");
3496 		break;
3497 
3498 	case ISCSI_TASK_FUNC_LOGICAL_UNIT_RESET:
3499 		SPDK_NOTICELOG("LOGICAL_UNIT_RESET\n");
3500 
3501 		spdk_iscsi_op_abort_task_set(task, SPDK_SCSI_TASK_FUNC_LUN_RESET);
3502 		return SPDK_SUCCESS;
3503 
3504 	case ISCSI_TASK_FUNC_TARGET_WARM_RESET:
3505 		SPDK_NOTICELOG("TARGET_WARM_RESET (Unsupported)\n");
3506 
3507 #if 0
3508 		spdk_iscsi_drop_conns(conn, conn->initiator_name, 1 /* drop all */);
3509 		rc = spdk_iscsi_tgt_node_reset(conn->sess->target, lun);
3510 		if (rc < 0) {
3511 			SPDK_ERRLOG("tgt_node reset failed\n");
3512 		}
3513 #else
3514 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3515 #endif
3516 		break;
3517 
3518 	case ISCSI_TASK_FUNC_TARGET_COLD_RESET:
3519 		SPDK_NOTICELOG("TARGET_COLD_RESET\n");
3520 
3521 #if 0
3522 		spdk_iscsi_drop_conns(conn, conn->initiator_name, 1 /* drop all */);
3523 
3524 		rc = spdk_iscsi_tgt_node_reset(conn->sess->target, lun);
3525 		if (rc < 0) {
3526 			SPDK_ERRLOG("tgt_node reset failed\n");
3527 		}
3528 
3529 		conn->state = ISCSI_CONN_STATE_EXITING;
3530 #else
3531 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3532 #endif
3533 		break;
3534 
3535 	case ISCSI_TASK_FUNC_TASK_REASSIGN:
3536 		SPDK_NOTICELOG("TASK_REASSIGN (Unsupported)\n");
3537 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3538 		break;
3539 
3540 	default:
3541 		SPDK_ERRLOG("unsupported function %d\n", function);
3542 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT;
3543 		break;
3544 	}
3545 
3546 	spdk_iscsi_task_mgmt_response(conn, task);
3547 	spdk_iscsi_task_put(task);
3548 	return 0;
3549 }
3550 
3551 static int
3552 iscsi_op_nopout(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3553 {
3554 	struct spdk_iscsi_pdu *rsp_pdu;
3555 	struct iscsi_bhs_nop_out *reqh;
3556 	struct iscsi_bhs_nop_in *rsph;
3557 	uint8_t *data;
3558 	uint64_t lun;
3559 	uint32_t task_tag;
3560 	uint32_t transfer_tag;
3561 	uint32_t CmdSN;
3562 	int I_bit;
3563 	int data_len;
3564 
3565 	if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
3566 		SPDK_ERRLOG("ISCSI_OP_NOPOUT not allowed in discovery session\n");
3567 		return SPDK_ISCSI_CONNECTION_FATAL;
3568 	}
3569 
3570 	reqh = (struct iscsi_bhs_nop_out *)&pdu->bhs;
3571 	I_bit = reqh->immediate;
3572 
3573 	data_len = DGET24(reqh->data_segment_len);
3574 	if (data_len > conn->MaxRecvDataSegmentLength) {
3575 		data_len = conn->MaxRecvDataSegmentLength;
3576 	}
3577 
3578 	lun = from_be64(&reqh->lun);
3579 	task_tag = from_be32(&reqh->itt);
3580 	transfer_tag = from_be32(&reqh->ttt);
3581 	CmdSN = from_be32(&reqh->cmd_sn);
3582 	pdu->cmd_sn = CmdSN;
3583 
3584 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "I=%d, ITT=%x, TTT=%x\n",
3585 		      I_bit, task_tag, transfer_tag);
3586 
3587 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "CmdSN=%u, StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
3588 		      CmdSN, conn->StatSN, conn->sess->ExpCmdSN,
3589 		      conn->sess->MaxCmdSN);
3590 
3591 	if (transfer_tag != 0xFFFFFFFF && transfer_tag != (uint32_t)conn->id) {
3592 		SPDK_ERRLOG("invalid transfer tag 0x%x\n", transfer_tag);
3593 		/*
3594 		 * Technically we should probably fail the connection here, but for now
3595 		 *  just print the error message and continue.
3596 		 */
3597 	}
3598 
3599 	/*
3600 	 * We don't actually check to see if this is a response to the NOP-In
3601 	 * that we sent.  Our goal is to just verify that the initiator is
3602 	 * alive and responding to commands, not to verify that it tags
3603 	 * NOP-Outs correctly
3604 	 */
3605 	conn->nop_outstanding = false;
3606 
3607 	if (task_tag == 0xffffffffU) {
3608 		if (I_bit == 1) {
3609 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "got NOPOUT ITT=0xffffffff\n");
3610 			return SPDK_SUCCESS;
3611 		} else {
3612 			SPDK_ERRLOG("got NOPOUT ITT=0xffffffff, I=0\n");
3613 			return SPDK_ISCSI_CONNECTION_FATAL;
3614 		}
3615 	}
3616 
3617 	data = calloc(1, data_len);
3618 	if (!data) {
3619 		SPDK_ERRLOG("calloc() failed for ping data\n");
3620 		return SPDK_ISCSI_CONNECTION_FATAL;
3621 	}
3622 
3623 	/* response of NOPOUT */
3624 	if (data_len > 0) {
3625 		/* copy ping data */
3626 		memcpy(data, pdu->data, data_len);
3627 	}
3628 
3629 	transfer_tag = 0xffffffffU;
3630 
3631 	/* response PDU */
3632 	rsp_pdu = spdk_get_pdu();
3633 	if (rsp_pdu == NULL) {
3634 		free(data);
3635 		return SPDK_ISCSI_CONNECTION_FATAL;
3636 	}
3637 	rsph = (struct iscsi_bhs_nop_in *)&rsp_pdu->bhs;
3638 	rsp_pdu->data = data;
3639 	rsph->opcode = ISCSI_OP_NOPIN;
3640 	rsph->flags |= 0x80; /* bit 0 default to 1 */
3641 	DSET24(rsph->data_segment_len, data_len);
3642 	to_be64(&rsph->lun, lun);
3643 	to_be32(&rsph->itt, task_tag);
3644 	to_be32(&rsph->ttt, transfer_tag);
3645 
3646 	to_be32(&rsph->stat_sn, conn->StatSN);
3647 	conn->StatSN++;
3648 
3649 	if (I_bit == 0) {
3650 		conn->sess->MaxCmdSN++;
3651 	}
3652 
3653 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
3654 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
3655 
3656 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
3657 	conn->last_nopin = spdk_get_ticks();
3658 
3659 	return SPDK_SUCCESS;
3660 }
3661 
3662 static int
3663 add_transfer_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
3664 {
3665 	uint32_t transfer_len;
3666 	size_t max_burst_len;
3667 	size_t segment_len;
3668 	size_t data_len;
3669 	int len;
3670 	int idx;
3671 	int rc;
3672 	int data_out_req;
3673 
3674 	transfer_len = task->scsi.transfer_len;
3675 	data_len = spdk_iscsi_task_get_pdu(task)->data_segment_len;
3676 	max_burst_len = conn->sess->MaxBurstLength;
3677 	segment_len = SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH;
3678 	data_out_req = 1 + (transfer_len - data_len - 1) / segment_len;
3679 	task->data_out_cnt = data_out_req;
3680 
3681 	/*
3682 	 * If we already have too many tasks using R2T, then queue this task
3683 	 *  and start sending R2T for it after some of the tasks using R2T/data
3684 	 *  out buffers complete.
3685 	 */
3686 	if (conn->pending_r2t >= DEFAULT_MAXR2T) {
3687 		TAILQ_INSERT_TAIL(&conn->queued_r2t_tasks, task, link);
3688 		return SPDK_SUCCESS;
3689 	}
3690 
3691 	conn->data_out_cnt += data_out_req;
3692 	idx = conn->pending_r2t++;
3693 
3694 	conn->outstanding_r2t_tasks[idx] = task;
3695 	task->next_expected_r2t_offset = data_len;
3696 	task->current_r2t_length = 0;
3697 	task->R2TSN = 0;
3698 	/* According to RFC3720 10.8.5, 0xffffffff is
3699 	 * reserved for TTT in R2T.
3700 	 */
3701 	if (++conn->ttt == 0xffffffffu) {
3702 		conn->ttt = 0;
3703 	}
3704 	task->ttt = conn->ttt;
3705 
3706 	while (data_len != transfer_len) {
3707 		len = DMIN32(max_burst_len, (transfer_len - data_len));
3708 		rc = iscsi_send_r2t(conn, task, data_len, len,
3709 				    task->ttt, &task->R2TSN);
3710 		if (rc < 0) {
3711 			SPDK_ERRLOG("iscsi_send_r2t() failed\n");
3712 			return rc;
3713 		}
3714 		data_len += len;
3715 		task->next_r2t_offset = data_len;
3716 		task->outstanding_r2t++;
3717 		if (conn->sess->MaxOutstandingR2T == task->outstanding_r2t) {
3718 			break;
3719 		}
3720 	}
3721 
3722 	TAILQ_INSERT_TAIL(&conn->active_r2t_tasks, task, link);
3723 	return SPDK_SUCCESS;
3724 }
3725 
3726 /* If there are additional large writes queued for R2Ts, start them now.
3727  *  This is called when a large write is just completed or when multiple LUNs
3728  *  are attached and large write tasks for the specific LUN are cleared.
3729  */
3730 static void
3731 start_queued_transfer_tasks(struct spdk_iscsi_conn *conn)
3732 {
3733 	struct spdk_iscsi_task *task, *tmp;
3734 
3735 	TAILQ_FOREACH_SAFE(task, &conn->queued_r2t_tasks, link, tmp) {
3736 		if (conn->pending_r2t < DEFAULT_MAXR2T) {
3737 			TAILQ_REMOVE(&conn->queued_r2t_tasks, task, link);
3738 			add_transfer_task(conn, task);
3739 		} else {
3740 			break;
3741 		}
3742 	}
3743 }
3744 
3745 void spdk_del_transfer_task(struct spdk_iscsi_conn *conn, uint32_t task_tag)
3746 {
3747 	struct spdk_iscsi_task *task;
3748 	int i;
3749 
3750 	for (i = 0; i < conn->pending_r2t; i++) {
3751 		if (conn->outstanding_r2t_tasks[i]->tag == task_tag) {
3752 			task = conn->outstanding_r2t_tasks[i];
3753 			conn->data_out_cnt -= task->data_out_cnt;
3754 
3755 			conn->pending_r2t--;
3756 			for (; i < conn->pending_r2t; i++) {
3757 				conn->outstanding_r2t_tasks[i] = conn->outstanding_r2t_tasks[i + 1];
3758 			}
3759 			conn->outstanding_r2t_tasks[conn->pending_r2t] = NULL;
3760 			break;
3761 		}
3762 	}
3763 
3764 	start_queued_transfer_tasks(conn);
3765 }
3766 
3767 static void
3768 del_connection_queued_task(struct spdk_iscsi_conn *conn, void *tailq,
3769 			   struct spdk_scsi_lun *lun,
3770 			   struct spdk_iscsi_pdu *pdu)
3771 {
3772 	struct spdk_iscsi_task *task, *task_tmp;
3773 	struct spdk_iscsi_pdu *pdu_tmp;
3774 
3775 	/*
3776 	 * Temporary used to index spdk_scsi_task related
3777 	 *  queues of the connection.
3778 	 */
3779 	TAILQ_HEAD(queued_tasks, spdk_iscsi_task) *head;
3780 	head = (struct queued_tasks *)tailq;
3781 
3782 	TAILQ_FOREACH_SAFE(task, head, link, task_tmp) {
3783 		pdu_tmp = spdk_iscsi_task_get_pdu(task);
3784 		if ((lun == NULL || lun == task->scsi.lun) &&
3785 		    (pdu == NULL || SN32_LT(pdu_tmp->cmd_sn, pdu->cmd_sn))) {
3786 			TAILQ_REMOVE(head, task, link);
3787 			if (lun != NULL && spdk_scsi_lun_is_removing(lun)) {
3788 				spdk_scsi_task_process_null_lun(&task->scsi);
3789 				spdk_iscsi_task_response(conn, task);
3790 			}
3791 			spdk_iscsi_task_put(task);
3792 		}
3793 	}
3794 }
3795 
3796 void spdk_clear_all_transfer_task(struct spdk_iscsi_conn *conn,
3797 				  struct spdk_scsi_lun *lun,
3798 				  struct spdk_iscsi_pdu *pdu)
3799 {
3800 	int i, j, pending_r2t;
3801 	struct spdk_iscsi_task *task;
3802 	struct spdk_iscsi_pdu *pdu_tmp;
3803 
3804 	pending_r2t = conn->pending_r2t;
3805 	for (i = 0; i < pending_r2t; i++) {
3806 		task = conn->outstanding_r2t_tasks[i];
3807 		pdu_tmp = spdk_iscsi_task_get_pdu(task);
3808 		if ((lun == NULL || lun == task->scsi.lun) &&
3809 		    (pdu == NULL || SN32_LT(pdu_tmp->cmd_sn, pdu->cmd_sn))) {
3810 			conn->outstanding_r2t_tasks[i] = NULL;
3811 			task->outstanding_r2t = 0;
3812 			task->next_r2t_offset = 0;
3813 			task->next_expected_r2t_offset = 0;
3814 			conn->data_out_cnt -= task->data_out_cnt;
3815 			conn->pending_r2t--;
3816 		}
3817 	}
3818 
3819 	for (i = 0; i < pending_r2t; i++) {
3820 		if (conn->outstanding_r2t_tasks[i] != NULL) {
3821 			continue;
3822 		}
3823 		for (j = i + 1; j < pending_r2t; j++) {
3824 			if (conn->outstanding_r2t_tasks[j] != NULL) {
3825 				conn->outstanding_r2t_tasks[i] = conn->outstanding_r2t_tasks[j];
3826 				conn->outstanding_r2t_tasks[j] = NULL;
3827 				break;
3828 			}
3829 		}
3830 	}
3831 
3832 	del_connection_queued_task(conn, &conn->active_r2t_tasks, lun, pdu);
3833 	del_connection_queued_task(conn, &conn->queued_r2t_tasks, lun, pdu);
3834 
3835 	start_queued_transfer_tasks(conn);
3836 }
3837 
3838 /* This function is used to handle the r2t snack */
3839 static int
3840 iscsi_handle_r2t_snack(struct spdk_iscsi_conn *conn,
3841 		       struct spdk_iscsi_task *task,
3842 		       struct spdk_iscsi_pdu *pdu, uint32_t beg_run,
3843 		       uint32_t run_length, int32_t task_tag)
3844 {
3845 	int32_t last_r2tsn;
3846 	int i;
3847 
3848 	if (beg_run < task->acked_r2tsn) {
3849 		SPDK_ERRLOG("ITT: 0x%08x, R2T SNACK requests retransmission of"
3850 			    "R2TSN: from 0x%08x to 0x%08x. But it has already"
3851 			    "ack to R2TSN:0x%08x, protocol error.\n",
3852 			    task_tag, beg_run, (beg_run + run_length),
3853 			    (task->acked_r2tsn - 1));
3854 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3855 	}
3856 
3857 	if (run_length) {
3858 		if ((beg_run + run_length) > task->R2TSN) {
3859 			SPDK_ERRLOG("ITT: 0x%08x, received R2T SNACK with"
3860 				    "BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
3861 				    "current R2TSN: 0x%08x, protocol error.\n",
3862 				    task_tag, beg_run, run_length,
3863 				    task->R2TSN);
3864 
3865 			return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_PDU_FIELD);
3866 		}
3867 		last_r2tsn = (beg_run + run_length);
3868 	} else {
3869 		last_r2tsn = task->R2TSN;
3870 	}
3871 
3872 	for (i = beg_run; i < last_r2tsn; i++) {
3873 		if (iscsi_send_r2t_recovery(conn, task, i, false) < 0) {
3874 			SPDK_ERRLOG("The r2t_sn=%d of r2t_task=%p is not sent\n", i, task);
3875 		}
3876 	}
3877 	return 0;
3878 }
3879 
3880 /* This function is used to recover the data in packet */
3881 static int
3882 iscsi_handle_recovery_datain(struct spdk_iscsi_conn *conn,
3883 			     struct spdk_iscsi_task *task,
3884 			     struct spdk_iscsi_pdu *pdu, uint32_t beg_run,
3885 			     uint32_t run_length, uint32_t task_tag)
3886 {
3887 	struct spdk_iscsi_pdu *old_pdu, *pdu_temp;
3888 	uint32_t i;
3889 	struct iscsi_bhs_data_in *datain_header;
3890 	uint32_t last_statsn;
3891 
3892 	task = spdk_iscsi_task_get_primary(task);
3893 
3894 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "iscsi_handle_recovery_datain\n");
3895 
3896 	if (beg_run < task->acked_data_sn) {
3897 		SPDK_ERRLOG("ITT: 0x%08x, DATA IN SNACK requests retransmission of"
3898 			    "DATASN: from 0x%08x to 0x%08x but already acked to "
3899 			    "DATASN: 0x%08x protocol error\n",
3900 			    task_tag, beg_run,
3901 			    (beg_run + run_length), (task->acked_data_sn - 1));
3902 
3903 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3904 	}
3905 
3906 	if (run_length == 0) {
3907 		/* as the DataSN begins at 0 */
3908 		run_length = task->datain_datasn + 1;
3909 	}
3910 
3911 	if ((beg_run + run_length - 1) > task->datain_datasn) {
3912 		SPDK_ERRLOG("Initiator requests BegRun: 0x%08x, RunLength:"
3913 			    "0x%08x greater than maximum DataSN: 0x%08x.\n",
3914 			    beg_run, run_length, task->datain_datasn);
3915 
3916 		return -1;
3917 	} else {
3918 		last_statsn = beg_run + run_length - 1;
3919 	}
3920 
3921 	for (i = beg_run; i <= last_statsn; i++) {
3922 		TAILQ_FOREACH_SAFE(old_pdu, &conn->snack_pdu_list, tailq, pdu_temp) {
3923 			if (old_pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
3924 				datain_header = (struct iscsi_bhs_data_in *)&old_pdu->bhs;
3925 				if (from_be32(&datain_header->itt) == task_tag &&
3926 				    from_be32(&datain_header->data_sn) == i) {
3927 					TAILQ_REMOVE(&conn->snack_pdu_list, old_pdu, tailq);
3928 					spdk_iscsi_conn_write_pdu(conn, old_pdu);
3929 					break;
3930 				}
3931 			}
3932 		}
3933 	}
3934 	return 0;
3935 }
3936 
3937 /* This function is used to handle the status snack */
3938 static int
3939 iscsi_handle_status_snack(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3940 {
3941 	uint32_t beg_run;
3942 	uint32_t run_length;
3943 	struct iscsi_bhs_snack_req *reqh;
3944 	uint32_t i;
3945 	uint32_t last_statsn;
3946 	bool found_pdu;
3947 	struct spdk_iscsi_pdu *old_pdu;
3948 
3949 	reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
3950 	beg_run = from_be32(&reqh->beg_run);
3951 	run_length = from_be32(&reqh->run_len);
3952 
3953 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "beg_run=%d, run_length=%d, conn->StatSN="
3954 		      "%d, conn->exp_statsn=%d\n", beg_run, run_length,
3955 		      conn->StatSN, conn->exp_statsn);
3956 
3957 	if (!beg_run) {
3958 		beg_run = conn->exp_statsn;
3959 	} else if (beg_run < conn->exp_statsn) {
3960 		SPDK_ERRLOG("Got Status SNACK Begrun: 0x%08x, RunLength: 0x%08x "
3961 			    "but already got ExpStatSN: 0x%08x on CID:%hu.\n",
3962 			    beg_run, run_length, conn->StatSN, conn->cid);
3963 
3964 		return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_PDU_FIELD);
3965 	}
3966 
3967 	last_statsn = (!run_length) ? conn->StatSN : (beg_run + run_length);
3968 
3969 	for (i = beg_run; i < last_statsn; i++) {
3970 		found_pdu = false;
3971 		TAILQ_FOREACH(old_pdu, &conn->snack_pdu_list, tailq) {
3972 			if (from_be32(&old_pdu->bhs.stat_sn) == i) {
3973 				found_pdu = true;
3974 				break;
3975 			}
3976 		}
3977 
3978 		if (!found_pdu) {
3979 			SPDK_ERRLOG("Unable to find StatSN: 0x%08x. For a Status"
3980 				    "SNACK, assuming this is a proactive SNACK "
3981 				    "for an untransmitted StatSN, ignoring.\n",
3982 				    beg_run);
3983 		} else {
3984 			TAILQ_REMOVE(&conn->snack_pdu_list, old_pdu, tailq);
3985 			spdk_iscsi_conn_write_pdu(conn, old_pdu);
3986 		}
3987 	}
3988 
3989 	return 0;
3990 }
3991 
3992 /* This function is used to handle the data ack snack */
3993 static int
3994 iscsi_handle_data_ack(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3995 {
3996 	uint32_t transfer_tag;
3997 	uint32_t beg_run;
3998 	uint32_t run_length;
3999 	struct spdk_iscsi_pdu *old_pdu;
4000 	uint32_t old_datasn;
4001 	struct iscsi_bhs_snack_req *reqh;
4002 	struct spdk_iscsi_task *task;
4003 	struct iscsi_bhs_data_in *datain_header;
4004 	struct spdk_iscsi_task *primary;
4005 
4006 	reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
4007 	transfer_tag = from_be32(&reqh->ttt);
4008 	beg_run = from_be32(&reqh->beg_run);
4009 	run_length = from_be32(&reqh->run_len);
4010 	task = NULL;
4011 	datain_header = NULL;
4012 
4013 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "beg_run=%d,transfer_tag=%d,run_len=%d\n",
4014 		      beg_run, transfer_tag, run_length);
4015 
4016 	task = get_scsi_task_from_ttt(conn, transfer_tag);
4017 	if (!task) {
4018 		SPDK_ERRLOG("Data ACK SNACK for TTT: 0x%08x is invalid.\n",
4019 			    transfer_tag);
4020 		goto reject_return;
4021 	}
4022 
4023 	primary = spdk_iscsi_task_get_primary(task);
4024 	if ((run_length != 0) || (beg_run < primary->acked_data_sn)) {
4025 		SPDK_ERRLOG("TTT: 0x%08x Data ACK SNACK BegRUN: %d is less than "
4026 			    "the next expected acked DataSN: %d\n",
4027 			    transfer_tag, beg_run, primary->acked_data_sn);
4028 		goto reject_return;
4029 	}
4030 
4031 	primary->acked_data_sn = beg_run;
4032 
4033 	/* To free the pdu */
4034 	TAILQ_FOREACH(old_pdu, &conn->snack_pdu_list, tailq) {
4035 		if (old_pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
4036 			datain_header = (struct iscsi_bhs_data_in *) &old_pdu->bhs;
4037 			old_datasn = from_be32(&datain_header->data_sn);
4038 			if ((from_be32(&datain_header->ttt) == transfer_tag) &&
4039 			    (old_datasn == beg_run - 1)) {
4040 				TAILQ_REMOVE(&conn->snack_pdu_list, old_pdu, tailq);
4041 				if (old_pdu->task) {
4042 					spdk_iscsi_task_put(old_pdu->task);
4043 				}
4044 				spdk_put_pdu(old_pdu);
4045 				break;
4046 			}
4047 		}
4048 	}
4049 
4050 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Received Data ACK SNACK for TTT: 0x%08x,"
4051 		      " updated acked DataSN to 0x%08x.\n", transfer_tag,
4052 		      (task->acked_data_sn - 1));
4053 
4054 	return 0;
4055 
4056 reject_return:
4057 	return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_SNACK);
4058 }
4059 
4060 /* This function is used to remove the r2t pdu from snack_pdu_list by < task, r2t_sn> info */
4061 static struct spdk_iscsi_pdu *
4062 iscsi_remove_r2t_pdu_from_snack_list(struct spdk_iscsi_conn *conn,
4063 				     struct spdk_iscsi_task *task,
4064 				     uint32_t r2t_sn)
4065 {
4066 	struct spdk_iscsi_pdu *pdu;
4067 	struct iscsi_bhs_r2t *r2t_header;
4068 
4069 	TAILQ_FOREACH(pdu, &conn->snack_pdu_list, tailq) {
4070 		if (pdu->bhs.opcode == ISCSI_OP_R2T) {
4071 			r2t_header = (struct iscsi_bhs_r2t *)&pdu->bhs;
4072 			if (pdu->task == task &&
4073 			    from_be32(&r2t_header->r2t_sn) == r2t_sn) {
4074 				TAILQ_REMOVE(&conn->snack_pdu_list, pdu, tailq);
4075 				return pdu;
4076 			}
4077 		}
4078 	}
4079 
4080 	return NULL;
4081 }
4082 
4083 /* This function is used re-send the r2t packet */
4084 static int
4085 iscsi_send_r2t_recovery(struct spdk_iscsi_conn *conn,
4086 			struct spdk_iscsi_task *task, uint32_t r2t_sn,
4087 			bool send_new_r2tsn)
4088 {
4089 	struct spdk_iscsi_pdu *pdu;
4090 	struct iscsi_bhs_r2t *rsph;
4091 	uint32_t transfer_len;
4092 	uint32_t len;
4093 	int rc;
4094 
4095 	/* remove the r2t pdu from the snack_list */
4096 	pdu = iscsi_remove_r2t_pdu_from_snack_list(conn, task, r2t_sn);
4097 	if (!pdu) {
4098 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "No pdu is found\n");
4099 		return -1;
4100 	}
4101 
4102 	/* flag
4103 	 * false: only need to re-send the old r2t with changing statsn
4104 	 * true: we send a r2t with new r2tsn
4105 	 */
4106 	if (!send_new_r2tsn) {
4107 		to_be32(&pdu->bhs.stat_sn, conn->StatSN);
4108 		spdk_iscsi_conn_write_pdu(conn, pdu);
4109 	} else {
4110 		rsph = (struct iscsi_bhs_r2t *)&pdu->bhs;
4111 		transfer_len = from_be32(&rsph->desired_xfer_len);
4112 
4113 		/* still need to increase the acked r2tsn */
4114 		task->acked_r2tsn++;
4115 		len = DMIN32(conn->sess->MaxBurstLength, (transfer_len -
4116 				task->next_expected_r2t_offset));
4117 
4118 		/* remove the old_r2t_pdu */
4119 		if (pdu->task) {
4120 			spdk_iscsi_task_put(pdu->task);
4121 		}
4122 		spdk_put_pdu(pdu);
4123 
4124 		/* re-send a new r2t pdu */
4125 		rc = iscsi_send_r2t(conn, task, task->next_expected_r2t_offset,
4126 				    len, task->ttt, &task->R2TSN);
4127 		if (rc < 0) {
4128 			return SPDK_ISCSI_CONNECTION_FATAL;
4129 		}
4130 	}
4131 
4132 	return 0;
4133 }
4134 
4135 /* This function is used to handle the snack request from the initiator */
4136 static int
4137 iscsi_op_snack(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4138 {
4139 	struct iscsi_bhs_snack_req *reqh;
4140 	struct spdk_iscsi_task *task;
4141 	int type;
4142 	uint32_t task_tag;
4143 	uint32_t beg_run;
4144 	uint32_t run_length;
4145 	int rc;
4146 
4147 	if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
4148 		SPDK_ERRLOG("ISCSI_OP_SNACK not allowed in  discovery session\n");
4149 		return SPDK_ISCSI_CONNECTION_FATAL;
4150 	}
4151 
4152 	reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
4153 	if (!conn->sess->ErrorRecoveryLevel) {
4154 		SPDK_ERRLOG("Got a SNACK request in ErrorRecoveryLevel=0\n");
4155 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4156 	}
4157 
4158 	type = reqh->flags & ISCSI_FLAG_SNACK_TYPE_MASK;
4159 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "The value of type is %d\n", type);
4160 
4161 	switch (type) {
4162 	case 0:
4163 		reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
4164 		task_tag = from_be32(&reqh->itt);
4165 		beg_run = from_be32(&reqh->beg_run);
4166 		run_length = from_be32(&reqh->run_len);
4167 
4168 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "beg_run=%d, run_length=%d, "
4169 			      "task_tag=%x, transfer_tag=%u\n", beg_run,
4170 			      run_length, task_tag, from_be32(&reqh->ttt));
4171 
4172 		task = get_scsi_task_from_itt(conn, task_tag,
4173 					      ISCSI_OP_SCSI_DATAIN);
4174 		if (task) {
4175 			return iscsi_handle_recovery_datain(conn, task, pdu,
4176 							    beg_run, run_length, task_tag);
4177 		}
4178 		task = get_scsi_task_from_itt(conn, task_tag, ISCSI_OP_R2T);
4179 		if (task) {
4180 			return iscsi_handle_r2t_snack(conn, task, pdu, beg_run,
4181 						      run_length, task_tag);
4182 		}
4183 		SPDK_ERRLOG("It is Neither datain nor r2t recovery request\n");
4184 		rc = -1;
4185 		break;
4186 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
4187 		rc = iscsi_handle_status_snack(conn, pdu);
4188 		break;
4189 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
4190 		rc = iscsi_handle_data_ack(conn, pdu);
4191 		break;
4192 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
4193 		SPDK_ERRLOG("R-Data SNACK is Not Supported int spdk\n");
4194 		rc = iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4195 		break;
4196 	default:
4197 		SPDK_ERRLOG("Unknown SNACK type %d, protocol error\n", type);
4198 		rc = iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4199 		break;
4200 	}
4201 
4202 	return rc;
4203 }
4204 
4205 /* This function is used to refree the pdu when it is acknowledged */
4206 static void
4207 remove_acked_pdu(struct spdk_iscsi_conn *conn, uint32_t ExpStatSN)
4208 {
4209 	struct spdk_iscsi_pdu *pdu, *pdu_temp;
4210 	uint32_t stat_sn;
4211 
4212 	conn->exp_statsn = DMIN32(ExpStatSN, conn->StatSN);
4213 	TAILQ_FOREACH_SAFE(pdu, &conn->snack_pdu_list, tailq, pdu_temp) {
4214 		stat_sn = from_be32(&pdu->bhs.stat_sn);
4215 		if (SN32_LT(stat_sn, conn->exp_statsn)) {
4216 			TAILQ_REMOVE(&conn->snack_pdu_list, pdu, tailq);
4217 			spdk_iscsi_conn_free_pdu(conn, pdu);
4218 		}
4219 	}
4220 }
4221 
4222 static int
4223 iscsi_op_data(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4224 {
4225 	struct spdk_iscsi_task	*task, *subtask;
4226 	struct iscsi_bhs_data_out *reqh;
4227 	struct spdk_scsi_lun	*lun_dev;
4228 	uint32_t transfer_tag;
4229 	uint32_t task_tag;
4230 	uint32_t transfer_len;
4231 	uint32_t DataSN;
4232 	uint32_t buffer_offset;
4233 	uint32_t len;
4234 	int F_bit;
4235 	int rc;
4236 	int reject_reason = ISCSI_REASON_INVALID_PDU_FIELD;
4237 
4238 	if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
4239 		SPDK_ERRLOG("ISCSI_OP_SCSI_DATAOUT not allowed in discovery session\n");
4240 		return SPDK_ISCSI_CONNECTION_FATAL;
4241 	}
4242 
4243 	reqh = (struct iscsi_bhs_data_out *)&pdu->bhs;
4244 	F_bit = !!(reqh->flags & ISCSI_FLAG_FINAL);
4245 	transfer_tag = from_be32(&reqh->ttt);
4246 	task_tag = from_be32(&reqh->itt);
4247 	DataSN = from_be32(&reqh->data_sn);
4248 	buffer_offset = from_be32(&reqh->buffer_offset);
4249 
4250 	task = get_transfer_task(conn, transfer_tag);
4251 	if (task == NULL) {
4252 		SPDK_ERRLOG("Not found task for transfer_tag=%x\n", transfer_tag);
4253 		goto reject_return;
4254 	}
4255 
4256 	lun_dev = spdk_scsi_dev_get_lun(conn->dev, task->lun_id);
4257 
4258 	if (pdu->data_segment_len > task->desired_data_transfer_length) {
4259 		SPDK_ERRLOG("the dataout pdu data length is larger than the value sent by R2T PDU\n");
4260 		return SPDK_ISCSI_CONNECTION_FATAL;
4261 	}
4262 
4263 	if (task->tag != task_tag) {
4264 		SPDK_ERRLOG("The r2t task tag is %u, and the dataout task tag is %u\n",
4265 			    task->tag, task_tag);
4266 		goto reject_return;
4267 	}
4268 
4269 	if (DataSN != task->r2t_datasn) {
4270 		SPDK_ERRLOG("DataSN(%u) exp=%d error\n", DataSN, task->r2t_datasn);
4271 		if (conn->sess->ErrorRecoveryLevel >= 1) {
4272 			goto send_r2t_recovery_return;
4273 		} else {
4274 			reject_reason = ISCSI_REASON_PROTOCOL_ERROR;
4275 			goto reject_return;
4276 		}
4277 	}
4278 
4279 	if (buffer_offset != task->next_expected_r2t_offset) {
4280 		SPDK_ERRLOG("offset(%u) error\n", buffer_offset);
4281 		return SPDK_ISCSI_CONNECTION_FATAL;
4282 	}
4283 
4284 	transfer_len = task->scsi.transfer_len;
4285 	task->current_r2t_length += pdu->data_segment_len;
4286 	task->next_expected_r2t_offset += pdu->data_segment_len;
4287 	task->r2t_datasn++;
4288 
4289 	if (task->current_r2t_length > conn->sess->MaxBurstLength) {
4290 		SPDK_ERRLOG("R2T burst(%u) > MaxBurstLength(%u)\n",
4291 			    task->current_r2t_length,
4292 			    conn->sess->MaxBurstLength);
4293 		return SPDK_ISCSI_CONNECTION_FATAL;
4294 	}
4295 
4296 	if (F_bit) {
4297 		/*
4298 		 * This R2T burst is done.  Clear the length before we
4299 		 *  receive a PDU for the next R2T burst.
4300 		 */
4301 		task->current_r2t_length = 0;
4302 	}
4303 
4304 	subtask = spdk_iscsi_task_get(conn, task, spdk_iscsi_task_cpl);
4305 	if (subtask == NULL) {
4306 		SPDK_ERRLOG("Unable to acquire subtask\n");
4307 		return SPDK_ISCSI_CONNECTION_FATAL;
4308 	}
4309 	subtask->scsi.offset = buffer_offset;
4310 	subtask->scsi.length = pdu->data_segment_len;
4311 	if (spdk_likely(!pdu->dif_insert_or_strip)) {
4312 		spdk_scsi_task_set_data(&subtask->scsi, pdu->data, pdu->data_segment_len);
4313 	} else {
4314 		spdk_scsi_task_set_data(&subtask->scsi, pdu->data, pdu->data_buf_len);
4315 	}
4316 	spdk_iscsi_task_associate_pdu(subtask, pdu);
4317 
4318 	if (task->next_expected_r2t_offset == transfer_len) {
4319 		task->acked_r2tsn++;
4320 	} else if (F_bit && (task->next_r2t_offset < transfer_len)) {
4321 		task->acked_r2tsn++;
4322 		len = DMIN32(conn->sess->MaxBurstLength, (transfer_len -
4323 				task->next_r2t_offset));
4324 		rc = iscsi_send_r2t(conn, task, task->next_r2t_offset, len,
4325 				    task->ttt, &task->R2TSN);
4326 		if (rc < 0) {
4327 			SPDK_ERRLOG("iscsi_send_r2t() failed\n");
4328 		}
4329 		task->next_r2t_offset += len;
4330 	}
4331 
4332 	if (lun_dev == NULL) {
4333 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "LUN %d is removed, complete the task immediately\n",
4334 			      task->lun_id);
4335 		subtask->scsi.transfer_len = subtask->scsi.length;
4336 		spdk_scsi_task_process_null_lun(&subtask->scsi);
4337 		spdk_iscsi_task_cpl(&subtask->scsi);
4338 		return 0;
4339 	}
4340 
4341 	iscsi_queue_task(conn, subtask);
4342 	return 0;
4343 
4344 send_r2t_recovery_return:
4345 	rc = iscsi_send_r2t_recovery(conn, task, task->acked_r2tsn, true);
4346 	if (rc == 0) {
4347 		return 0;
4348 	}
4349 
4350 reject_return:
4351 	return iscsi_reject(conn, pdu, reject_reason);
4352 }
4353 
4354 static int
4355 iscsi_send_r2t(struct spdk_iscsi_conn *conn,
4356 	       struct spdk_iscsi_task *task, int offset,
4357 	       int len, uint32_t transfer_tag, uint32_t *R2TSN)
4358 {
4359 	struct spdk_iscsi_pdu *rsp_pdu;
4360 	struct iscsi_bhs_r2t *rsph;
4361 	uint64_t fmt_lun;
4362 
4363 	/* R2T PDU */
4364 	rsp_pdu = spdk_get_pdu();
4365 	if (rsp_pdu == NULL) {
4366 		return SPDK_ISCSI_CONNECTION_FATAL;
4367 	}
4368 	rsph = (struct iscsi_bhs_r2t *)&rsp_pdu->bhs;
4369 	rsp_pdu->data = NULL;
4370 	rsph->opcode = ISCSI_OP_R2T;
4371 	rsph->flags |= 0x80; /* bit 0 is default to 1 */
4372 	fmt_lun = spdk_scsi_lun_id_int_to_fmt(task->lun_id);
4373 	to_be64(&rsph->lun, fmt_lun);
4374 	to_be32(&rsph->itt, task->tag);
4375 	to_be32(&rsph->ttt, transfer_tag);
4376 
4377 	to_be32(&rsph->stat_sn, conn->StatSN);
4378 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
4379 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
4380 
4381 	to_be32(&rsph->r2t_sn, *R2TSN);
4382 	*R2TSN += 1;
4383 
4384 	task->r2t_datasn = 0; /* next expected datasn to ack */
4385 
4386 	to_be32(&rsph->buffer_offset, (uint32_t)offset);
4387 	to_be32(&rsph->desired_xfer_len, (uint32_t)len);
4388 	task->desired_data_transfer_length = (size_t)len;
4389 
4390 	/* we need to hold onto this task/cmd because until the PDU has been
4391 	 * written out */
4392 	rsp_pdu->task = task;
4393 	task->scsi.ref++;
4394 
4395 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
4396 
4397 	return SPDK_SUCCESS;
4398 }
4399 
4400 void spdk_iscsi_send_nopin(struct spdk_iscsi_conn *conn)
4401 {
4402 	struct spdk_iscsi_pdu *rsp_pdu;
4403 	struct iscsi_bhs_nop_in	*rsp;
4404 
4405 	/* Only send nopin if we have logged in and are in a normal session. */
4406 	if (conn->sess == NULL ||
4407 	    !conn->full_feature ||
4408 	    !spdk_iscsi_param_eq_val(conn->sess->params, "SessionType", "Normal")) {
4409 		return;
4410 	}
4411 
4412 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "send NOPIN isid=%"PRIx64", tsih=%u, cid=%u\n",
4413 		      conn->sess->isid, conn->sess->tsih, conn->cid);
4414 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
4415 		      conn->StatSN, conn->sess->ExpCmdSN,
4416 		      conn->sess->MaxCmdSN);
4417 
4418 	rsp_pdu = spdk_get_pdu();
4419 	rsp = (struct iscsi_bhs_nop_in *) &rsp_pdu->bhs;
4420 	rsp_pdu->data = NULL;
4421 
4422 	/*
4423 	 * spdk_get_pdu() memset's the PDU for us, so only fill out the needed
4424 	 *  fields.
4425 	 */
4426 	rsp->opcode = ISCSI_OP_NOPIN;
4427 	rsp->flags = 0x80;
4428 	/*
4429 	 * Technically the to_be32() is not needed here, since
4430 	 *  to_be32(0xFFFFFFFU) returns 0xFFFFFFFFU.
4431 	 */
4432 	to_be32(&rsp->itt, 0xFFFFFFFFU);
4433 	to_be32(&rsp->ttt, conn->id);
4434 	to_be32(&rsp->stat_sn, conn->StatSN);
4435 	to_be32(&rsp->exp_cmd_sn, conn->sess->ExpCmdSN);
4436 	to_be32(&rsp->max_cmd_sn, conn->sess->MaxCmdSN);
4437 
4438 	spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
4439 	conn->last_nopin = spdk_get_ticks();
4440 	conn->nop_outstanding = true;
4441 }
4442 
4443 static void
4444 init_login_reject_response(struct spdk_iscsi_pdu *pdu, struct spdk_iscsi_pdu *rsp_pdu)
4445 {
4446 	struct iscsi_bhs_login_rsp *rsph;
4447 
4448 	memset(rsp_pdu, 0, sizeof(struct spdk_iscsi_pdu));
4449 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
4450 	rsph->version_max = ISCSI_VERSION;
4451 	rsph->version_act = ISCSI_VERSION;
4452 	rsph->opcode = ISCSI_OP_LOGIN_RSP;
4453 	rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
4454 	rsph->status_detail = ISCSI_LOGIN_INVALID_LOGIN_REQUEST;
4455 	rsph->itt = pdu->bhs.itt;
4456 }
4457 
4458 int
4459 spdk_iscsi_execute(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4460 {
4461 	int opcode;
4462 	int rc;
4463 	struct spdk_iscsi_pdu *rsp_pdu = NULL;
4464 	uint32_t ExpStatSN;
4465 	int I_bit;
4466 	struct spdk_iscsi_sess *sess;
4467 	struct iscsi_bhs_scsi_req *reqh;
4468 
4469 	if (pdu == NULL) {
4470 		return -1;
4471 	}
4472 
4473 	opcode = pdu->bhs.opcode;
4474 	reqh = (struct iscsi_bhs_scsi_req *)&pdu->bhs;
4475 	pdu->cmd_sn = from_be32(&reqh->cmd_sn);
4476 
4477 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "opcode %x\n", opcode);
4478 
4479 	if (opcode == ISCSI_OP_LOGIN) {
4480 		rc = iscsi_op_login(conn, pdu);
4481 		if (rc < 0) {
4482 			SPDK_ERRLOG("iscsi_op_login() failed\n");
4483 		}
4484 		return rc;
4485 	}
4486 
4487 	/* connection in login phase but receive non-login opcode
4488 	 * return response code 0x020b to initiator.
4489 	 * */
4490 	if (!conn->full_feature && conn->state == ISCSI_CONN_STATE_RUNNING) {
4491 		rsp_pdu = spdk_get_pdu();
4492 		if (rsp_pdu == NULL) {
4493 			return SPDK_ISCSI_CONNECTION_FATAL;
4494 		}
4495 		init_login_reject_response(pdu, rsp_pdu);
4496 		spdk_iscsi_conn_write_pdu(conn, rsp_pdu);
4497 		SPDK_ERRLOG("Received opcode %d in login phase\n", opcode);
4498 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
4499 	} else if (conn->state == ISCSI_CONN_STATE_INVALID) {
4500 		SPDK_ERRLOG("before Full Feature\n");
4501 		return SPDK_ISCSI_CONNECTION_FATAL;
4502 	}
4503 
4504 	sess = conn->sess;
4505 	if (!sess) {
4506 		SPDK_ERRLOG("Connection has no associated session!\n");
4507 		return SPDK_ISCSI_CONNECTION_FATAL;
4508 	}
4509 	I_bit = reqh->immediate;
4510 	if (I_bit == 0) {
4511 		if (SN32_LT(pdu->cmd_sn, sess->ExpCmdSN) ||
4512 		    SN32_GT(pdu->cmd_sn, sess->MaxCmdSN)) {
4513 			if (sess->session_type == SESSION_TYPE_NORMAL &&
4514 			    opcode != ISCSI_OP_SCSI_DATAOUT) {
4515 				SPDK_ERRLOG("CmdSN(%u) ignore (ExpCmdSN=%u, MaxCmdSN=%u)\n",
4516 					    pdu->cmd_sn, sess->ExpCmdSN, sess->MaxCmdSN);
4517 
4518 				if (sess->ErrorRecoveryLevel >= 1) {
4519 					SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Skip the error in ERL 1 and 2\n");
4520 				} else {
4521 					return SPDK_PDU_FATAL;
4522 				}
4523 			}
4524 		}
4525 	} else if (pdu->cmd_sn != sess->ExpCmdSN) {
4526 		SPDK_ERRLOG("CmdSN(%u) error ExpCmdSN=%u\n", pdu->cmd_sn, sess->ExpCmdSN);
4527 
4528 		if (sess->ErrorRecoveryLevel >= 1) {
4529 			SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Skip the error in ERL 1 and 2\n");
4530 		} else if (opcode != ISCSI_OP_NOPOUT) {
4531 			/*
4532 			 * The Linux initiator does not send valid CmdSNs for
4533 			 *  nopout under heavy load, so do not close the
4534 			 *  connection in that case.
4535 			 */
4536 			return SPDK_ISCSI_CONNECTION_FATAL;
4537 		}
4538 	}
4539 
4540 	ExpStatSN = from_be32(&reqh->exp_stat_sn);
4541 	if (SN32_GT(ExpStatSN, conn->StatSN)) {
4542 		SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "StatSN(%u) advanced\n", ExpStatSN);
4543 		ExpStatSN = conn->StatSN;
4544 	}
4545 
4546 	if (sess->ErrorRecoveryLevel >= 1) {
4547 		remove_acked_pdu(conn, ExpStatSN);
4548 	}
4549 
4550 	if (!I_bit && opcode != ISCSI_OP_SCSI_DATAOUT) {
4551 		sess->ExpCmdSN++;
4552 	}
4553 
4554 	switch (opcode) {
4555 	case ISCSI_OP_NOPOUT:
4556 		rc = iscsi_op_nopout(conn, pdu);
4557 		if (rc < 0) {
4558 			SPDK_ERRLOG("spdk_iscsi_op_nopout() failed\n");
4559 			return rc;
4560 		}
4561 		break;
4562 
4563 	case ISCSI_OP_SCSI:
4564 		rc = iscsi_op_scsi(conn, pdu);
4565 		if (rc < 0) {
4566 			SPDK_ERRLOG("spdk_iscsi_op_scsi() failed\n");
4567 			return rc;
4568 		}
4569 		break;
4570 	case ISCSI_OP_TASK:
4571 		rc = iscsi_op_task(conn, pdu);
4572 		if (rc < 0) {
4573 			SPDK_ERRLOG("spdk_iscsi_op_task() failed\n");
4574 			return rc;
4575 		}
4576 		break;
4577 
4578 	case ISCSI_OP_TEXT:
4579 		rc = iscsi_op_text(conn, pdu);
4580 		if (rc < 0) {
4581 			SPDK_ERRLOG("spdk_iscsi_op_text() failed\n");
4582 			return rc;
4583 		}
4584 		break;
4585 
4586 	case ISCSI_OP_LOGOUT:
4587 		rc = iscsi_op_logout(conn, pdu);
4588 		if (rc < 0) {
4589 			SPDK_ERRLOG("spdk_iscsi_op_logout() failed\n");
4590 			return rc;
4591 		}
4592 		break;
4593 
4594 	case ISCSI_OP_SCSI_DATAOUT:
4595 		rc = iscsi_op_data(conn, pdu);
4596 		if (rc < 0) {
4597 			SPDK_ERRLOG("spdk_iscsi_op_data() failed\n");
4598 			return rc;
4599 		}
4600 		break;
4601 
4602 	case ISCSI_OP_SNACK:
4603 		rc = iscsi_op_snack(conn, pdu);
4604 		if (rc < 0) {
4605 			SPDK_ERRLOG("spdk_iscsi_op_snack() failed\n");
4606 			return rc;
4607 		}
4608 		break;
4609 
4610 	default:
4611 		SPDK_ERRLOG("unsupported opcode %x\n", opcode);
4612 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4613 	}
4614 
4615 	return 0;
4616 }
4617 
4618 bool
4619 spdk_iscsi_get_dif_ctx(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu,
4620 		       struct spdk_dif_ctx *dif_ctx)
4621 {
4622 	struct iscsi_bhs *bhs;
4623 	uint32_t offset = 0;
4624 	uint8_t *cdb = NULL;
4625 	uint64_t lun;
4626 	int lun_id = 0;
4627 	struct spdk_scsi_lun *lun_dev;
4628 
4629 	/* connection is not in full feature phase but non-login opcode
4630 	 * was received.
4631 	 */
4632 	if ((!conn->full_feature && conn->state == ISCSI_CONN_STATE_RUNNING) ||
4633 	    conn->state == ISCSI_CONN_STATE_INVALID) {
4634 		return false;
4635 	}
4636 
4637 	/* SCSI Command is allowed only in normal session */
4638 	if (conn->sess == NULL ||
4639 	    conn->sess->session_type != SESSION_TYPE_NORMAL) {
4640 		return false;
4641 	}
4642 
4643 	bhs = &pdu->bhs;
4644 
4645 	switch (bhs->opcode) {
4646 	case ISCSI_OP_SCSI: {
4647 		struct iscsi_bhs_scsi_req *sbhs;
4648 
4649 		sbhs = (struct iscsi_bhs_scsi_req *)bhs;
4650 		offset = 0;
4651 		cdb = sbhs->cdb;
4652 		lun = from_be64(&sbhs->lun);
4653 		lun_id = spdk_scsi_lun_id_fmt_to_int(lun);
4654 		break;
4655 	}
4656 	case ISCSI_OP_SCSI_DATAOUT: {
4657 		struct iscsi_bhs_data_out *dbhs;
4658 		struct spdk_iscsi_task *task;
4659 		int transfer_tag;
4660 
4661 		dbhs = (struct iscsi_bhs_data_out *)bhs;
4662 		offset = from_be32(&dbhs->buffer_offset);
4663 		transfer_tag = from_be32(&dbhs->ttt);
4664 		task = get_transfer_task(conn, transfer_tag);
4665 		if (task == NULL) {
4666 			return false;
4667 		}
4668 		cdb = task->scsi.cdb;
4669 		lun_id = task->lun_id;
4670 		break;
4671 	}
4672 	case ISCSI_OP_SCSI_DATAIN: {
4673 		struct iscsi_bhs_data_in *dbhs;
4674 		struct spdk_iscsi_task *task;
4675 
4676 		dbhs = (struct iscsi_bhs_data_in *)bhs;
4677 		offset = from_be32(&dbhs->buffer_offset);
4678 		task = pdu->task;
4679 		assert(task != NULL);
4680 		cdb = task->scsi.cdb;
4681 		lun_id = task->lun_id;
4682 		break;
4683 	}
4684 	default:
4685 		return false;
4686 	}
4687 
4688 	lun_dev = spdk_scsi_dev_get_lun(conn->dev, lun_id);
4689 	if (lun_dev == NULL) {
4690 		return false;
4691 	}
4692 
4693 	return spdk_scsi_lun_get_dif_ctx(lun_dev, cdb, offset, dif_ctx);
4694 }
4695 
4696 void spdk_free_sess(struct spdk_iscsi_sess *sess)
4697 {
4698 	if (sess == NULL) {
4699 		return;
4700 	}
4701 
4702 	sess->tag = 0;
4703 	sess->target = NULL;
4704 	sess->session_type = SESSION_TYPE_INVALID;
4705 	spdk_iscsi_param_free(sess->params);
4706 	free(sess->conns);
4707 	spdk_scsi_port_free(&sess->initiator_port);
4708 	spdk_mempool_put(g_spdk_iscsi.session_pool, (void *)sess);
4709 }
4710 
4711 static int
4712 create_iscsi_sess(struct spdk_iscsi_conn *conn,
4713 		  struct spdk_iscsi_tgt_node *target,
4714 		  enum session_type session_type)
4715 {
4716 	struct spdk_iscsi_sess *sess;
4717 	int rc;
4718 
4719 	sess = spdk_mempool_get(g_spdk_iscsi.session_pool);
4720 	if (!sess) {
4721 		SPDK_ERRLOG("Unable to get session object\n");
4722 		SPDK_ERRLOG("MaxSessions set to %d\n", g_spdk_iscsi.MaxSessions);
4723 		return -ENOMEM;
4724 	}
4725 
4726 	/* configuration values */
4727 	pthread_mutex_lock(&g_spdk_iscsi.mutex);
4728 
4729 	sess->MaxConnections = g_spdk_iscsi.MaxConnectionsPerSession;
4730 	sess->MaxOutstandingR2T = DEFAULT_MAXOUTSTANDINGR2T;
4731 
4732 	sess->DefaultTime2Wait = g_spdk_iscsi.DefaultTime2Wait;
4733 	sess->DefaultTime2Retain = g_spdk_iscsi.DefaultTime2Retain;
4734 	sess->FirstBurstLength = g_spdk_iscsi.FirstBurstLength;
4735 	sess->MaxBurstLength = SPDK_ISCSI_MAX_BURST_LENGTH;
4736 	sess->InitialR2T = DEFAULT_INITIALR2T;
4737 	sess->ImmediateData = g_spdk_iscsi.ImmediateData;
4738 	sess->DataPDUInOrder = DEFAULT_DATAPDUINORDER;
4739 	sess->DataSequenceInOrder = DEFAULT_DATASEQUENCEINORDER;
4740 	sess->ErrorRecoveryLevel = g_spdk_iscsi.ErrorRecoveryLevel;
4741 
4742 	pthread_mutex_unlock(&g_spdk_iscsi.mutex);
4743 
4744 	sess->tag = conn->portal->group->tag;
4745 
4746 	sess->conns = calloc(sess->MaxConnections, sizeof(*sess->conns));
4747 	if (!sess->conns) {
4748 		SPDK_ERRLOG("calloc() failed for connection array\n");
4749 		return -ENOMEM;
4750 	}
4751 
4752 	sess->connections = 0;
4753 
4754 	sess->conns[sess->connections] = conn;
4755 	sess->connections++;
4756 
4757 	sess->params = NULL;
4758 	sess->target = target;
4759 	sess->isid = 0;
4760 	sess->session_type = session_type;
4761 	sess->current_text_itt = 0xffffffffU;
4762 
4763 	/* set default params */
4764 	rc = spdk_iscsi_sess_params_init(&sess->params);
4765 	if (rc < 0) {
4766 		SPDK_ERRLOG("iscsi_sess_params_init() failed\n");
4767 		goto error_return;
4768 	}
4769 	/* replace with config value */
4770 	rc = spdk_iscsi_param_set_int(sess->params, "MaxConnections",
4771 				      sess->MaxConnections);
4772 	if (rc < 0) {
4773 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4774 		goto error_return;
4775 	}
4776 
4777 	rc = spdk_iscsi_param_set_int(sess->params, "MaxOutstandingR2T",
4778 				      sess->MaxOutstandingR2T);
4779 	if (rc < 0) {
4780 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4781 		goto error_return;
4782 	}
4783 
4784 	rc = spdk_iscsi_param_set_int(sess->params, "DefaultTime2Wait",
4785 				      sess->DefaultTime2Wait);
4786 	if (rc < 0) {
4787 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4788 		goto error_return;
4789 	}
4790 
4791 	rc = spdk_iscsi_param_set_int(sess->params, "DefaultTime2Retain",
4792 				      sess->DefaultTime2Retain);
4793 	if (rc < 0) {
4794 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4795 		goto error_return;
4796 	}
4797 
4798 	rc = spdk_iscsi_param_set_int(sess->params, "FirstBurstLength",
4799 				      sess->FirstBurstLength);
4800 	if (rc < 0) {
4801 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4802 		goto error_return;
4803 	}
4804 
4805 	rc = spdk_iscsi_param_set_int(sess->params, "MaxBurstLength",
4806 				      sess->MaxBurstLength);
4807 	if (rc < 0) {
4808 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4809 		goto error_return;
4810 	}
4811 
4812 	rc = spdk_iscsi_param_set(sess->params, "InitialR2T",
4813 				  sess->InitialR2T ? "Yes" : "No");
4814 	if (rc < 0) {
4815 		SPDK_ERRLOG("iscsi_param_set() failed\n");
4816 		goto error_return;
4817 	}
4818 
4819 	rc = spdk_iscsi_param_set(sess->params, "ImmediateData",
4820 				  sess->ImmediateData ? "Yes" : "No");
4821 	if (rc < 0) {
4822 		SPDK_ERRLOG("iscsi_param_set() failed\n");
4823 		goto error_return;
4824 	}
4825 
4826 	rc = spdk_iscsi_param_set(sess->params, "DataPDUInOrder",
4827 				  sess->DataPDUInOrder ? "Yes" : "No");
4828 	if (rc < 0) {
4829 		SPDK_ERRLOG("iscsi_param_set() failed\n");
4830 		goto error_return;
4831 	}
4832 
4833 	rc = spdk_iscsi_param_set(sess->params, "DataSequenceInOrder",
4834 				  sess->DataSequenceInOrder ? "Yes" : "No");
4835 	if (rc < 0) {
4836 		SPDK_ERRLOG("iscsi_param_set() failed\n");
4837 		goto error_return;
4838 	}
4839 
4840 	rc = spdk_iscsi_param_set_int(sess->params, "ErrorRecoveryLevel",
4841 				      sess->ErrorRecoveryLevel);
4842 	if (rc < 0) {
4843 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4844 		goto error_return;
4845 	}
4846 
4847 	/* realloc buffer */
4848 	rc = spdk_iscsi_param_set_int(conn->params, "MaxRecvDataSegmentLength",
4849 				      conn->MaxRecvDataSegmentLength);
4850 	if (rc < 0) {
4851 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
4852 		goto error_return;
4853 	}
4854 
4855 	/* sess for first connection of session */
4856 	conn->sess = sess;
4857 	return 0;
4858 
4859 error_return:
4860 	spdk_free_sess(sess);
4861 	conn->sess = NULL;
4862 	return -1;
4863 }
4864 
4865 static struct spdk_iscsi_sess *
4866 get_iscsi_sess_by_tsih(uint16_t tsih)
4867 {
4868 	struct spdk_iscsi_sess *session;
4869 
4870 	if (tsih == 0 || tsih > g_spdk_iscsi.MaxSessions) {
4871 		return NULL;
4872 	}
4873 
4874 	session = g_spdk_iscsi.session[tsih - 1];
4875 	assert(tsih == session->tsih);
4876 
4877 	return session;
4878 }
4879 
4880 static int
4881 append_iscsi_sess(struct spdk_iscsi_conn *conn,
4882 		  const char *initiator_port_name, uint16_t tsih, uint16_t cid)
4883 {
4884 	struct spdk_iscsi_sess *sess;
4885 
4886 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "append session: init port name=%s, tsih=%u, cid=%u\n",
4887 		      initiator_port_name, tsih, cid);
4888 
4889 	sess = get_iscsi_sess_by_tsih(tsih);
4890 	if (sess == NULL) {
4891 		SPDK_ERRLOG("spdk_get_iscsi_sess_by_tsih failed\n");
4892 		return -1;
4893 	}
4894 	if ((conn->portal->group->tag != sess->tag) ||
4895 	    (strcasecmp(initiator_port_name, spdk_scsi_port_get_name(sess->initiator_port)) != 0) ||
4896 	    (conn->target != sess->target)) {
4897 		/* no match */
4898 		SPDK_ERRLOG("no MCS session for init port name=%s, tsih=%d, cid=%d\n",
4899 			    initiator_port_name, tsih, cid);
4900 		return -1;
4901 	}
4902 
4903 	if (sess->connections >= sess->MaxConnections) {
4904 		/* no slot for connection */
4905 		SPDK_ERRLOG("too many connections for init port name=%s, tsih=%d, cid=%d\n",
4906 			    initiator_port_name, tsih, cid);
4907 		return -1;
4908 	}
4909 
4910 	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Connections (tsih %d): %d\n", sess->tsih, sess->connections);
4911 	conn->sess = sess;
4912 
4913 	/*
4914 	 * TODO: need a mutex or other sync mechanism to protect the session's
4915 	 *  connection list.
4916 	 */
4917 	sess->conns[sess->connections] = conn;
4918 	sess->connections++;
4919 
4920 	return 0;
4921 }
4922 
4923 bool spdk_iscsi_is_deferred_free_pdu(struct spdk_iscsi_pdu *pdu)
4924 {
4925 	if (pdu == NULL) {
4926 		return false;
4927 	}
4928 
4929 	if (pdu->bhs.opcode == ISCSI_OP_R2T ||
4930 	    pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
4931 		return true;
4932 	}
4933 
4934 	return false;
4935 }
4936