xref: /spdk/lib/iscsi/iscsi.c (revision 4e8e97c886e47e337dc470ac8c1ffa044d729af0)
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/sock.h"
44 #include "spdk/string.h"
45 #include "spdk/queue.h"
46 #include "spdk/net.h"
47 
48 #include "iscsi/md5.h"
49 #include "iscsi/iscsi.h"
50 #include "iscsi/param.h"
51 #include "iscsi/tgt_node.h"
52 #include "iscsi/task.h"
53 #include "iscsi/conn.h"
54 #include "spdk/scsi.h"
55 #include "spdk/bdev.h"
56 #include "iscsi/portal_grp.h"
57 
58 #include "spdk/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_iscsi = {
71 	.mutex = PTHREAD_MUTEX_INITIALIZER,
72 	.portal_head = TAILQ_HEAD_INITIALIZER(g_iscsi.portal_head),
73 	.pg_head = TAILQ_HEAD_INITIALIZER(g_iscsi.pg_head),
74 	.ig_head = TAILQ_HEAD_INITIALIZER(g_iscsi.ig_head),
75 	.target_head = TAILQ_HEAD_INITIALIZER(g_iscsi.target_head),
76 	.auth_group_head = TAILQ_HEAD_INITIALIZER(g_iscsi.auth_group_head),
77 	.poll_group_head = TAILQ_HEAD_INITIALIZER(g_iscsi.poll_group_head),
78 };
79 
80 #define MATCH_DIGEST_WORD(BUF, CRC32C) \
81 	(    ((((uint32_t) *((uint8_t *)(BUF)+0)) << 0)		\
82 	    | (((uint32_t) *((uint8_t *)(BUF)+1)) << 8)		\
83 	    | (((uint32_t) *((uint8_t *)(BUF)+2)) << 16)	\
84 	    | (((uint32_t) *((uint8_t *)(BUF)+3)) << 24))	\
85 	    == (CRC32C))
86 
87 #ifndef HAVE_SRANDOMDEV
88 static void
89 srandomdev(void)
90 {
91 	unsigned long seed;
92 	time_t now;
93 	pid_t pid;
94 
95 	pid = getpid();
96 	now = time(NULL);
97 	seed = pid ^ now;
98 	srandom(seed);
99 }
100 #endif /* HAVE_SRANDOMDEV */
101 
102 #ifndef HAVE_ARC4RANDOM
103 static int g_arc4random_initialized = 0;
104 
105 static uint32_t
106 arc4random(void)
107 {
108 	uint32_t r;
109 	uint32_t r1, r2;
110 
111 	if (!g_arc4random_initialized) {
112 		srandomdev();
113 		g_arc4random_initialized = 1;
114 	}
115 	r1 = (uint32_t)(random() & 0xffff);
116 	r2 = (uint32_t)(random() & 0xffff);
117 	r = (r1 << 16) | r2;
118 	return r;
119 }
120 #endif /* HAVE_ARC4RANDOM */
121 
122 static void
123 gen_random(uint8_t *buf, size_t len)
124 {
125 	uint32_t r;
126 	size_t idx;
127 
128 	for (idx = 0; idx < len; idx++) {
129 		r = arc4random();
130 		buf[idx] = (uint8_t) r;
131 	}
132 }
133 
134 static uint64_t
135 iscsi_get_isid(const uint8_t isid[6])
136 {
137 	return (uint64_t)isid[0] << 40 |
138 	       (uint64_t)isid[1] << 32 |
139 	       (uint64_t)isid[2] << 24 |
140 	       (uint64_t)isid[3] << 16 |
141 	       (uint64_t)isid[4] << 8 |
142 	       (uint64_t)isid[5];
143 }
144 
145 static int
146 bin2hex(char *buf, size_t len, const uint8_t *data, size_t data_len)
147 {
148 	const char *digits = "0123456789ABCDEF";
149 	size_t total = 0;
150 	size_t idx;
151 
152 	if (len < 3) {
153 		return -1;
154 	}
155 	buf[total] = '0';
156 	total++;
157 	buf[total] = 'x';
158 	total++;
159 	buf[total] = '\0';
160 
161 	for (idx = 0; idx < data_len; idx++) {
162 		if (total + 3 > len) {
163 			buf[total] = '\0';
164 			return - 1;
165 		}
166 		buf[total] = digits[(data[idx] >> 4) & 0x0fU];
167 		total++;
168 		buf[total] = digits[data[idx] & 0x0fU];
169 		total++;
170 	}
171 	buf[total] = '\0';
172 	return total;
173 }
174 
175 static int
176 hex2bin(uint8_t *data, size_t data_len, const char *str)
177 {
178 	const char *digits = "0123456789ABCDEF";
179 	const char *dp;
180 	const char *p;
181 	size_t total = 0;
182 	int n0, n1;
183 
184 	p = str;
185 	if (p[0] != '0' && (p[1] != 'x' && p[1] != 'X')) {
186 		return -1;
187 	}
188 	p += 2;
189 
190 	while (p[0] != '\0' && p[1] != '\0') {
191 		if (total >= data_len) {
192 			return -1;
193 		}
194 		dp = strchr(digits, toupper((int) p[0]));
195 		if (dp == NULL) {
196 			return -1;
197 		}
198 		n0 = (int)(dp - digits);
199 		dp = strchr(digits, toupper((int) p[1]));
200 		if (dp == NULL) {
201 			return -1;
202 		}
203 		n1 = (int)(dp - digits);
204 
205 		data[total] = (uint8_t)(((n0 & 0x0fU) << 4) | (n1 & 0x0fU));
206 		total++;
207 		p += 2;
208 	}
209 	return total;
210 }
211 
212 static int
213 iscsi_reject(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu,
214 	     int reason)
215 {
216 	struct spdk_iscsi_pdu *rsp_pdu;
217 	struct iscsi_bhs_reject *rsph;
218 	uint8_t *data;
219 	int total_ahs_len;
220 	int data_len;
221 	int alloc_len;
222 
223 	pdu->is_rejected = true;
224 
225 	total_ahs_len = pdu->bhs.total_ahs_len;
226 	data_len = 0;
227 	alloc_len = ISCSI_BHS_LEN + (4 * total_ahs_len);
228 
229 	if (conn->header_digest) {
230 		alloc_len += ISCSI_DIGEST_LEN;
231 	}
232 
233 	data = calloc(1, alloc_len);
234 	if (!data) {
235 		SPDK_ERRLOG("calloc() failed for data segment\n");
236 		return -ENOMEM;
237 	}
238 
239 	SPDK_DEBUGLOG(iscsi, "Reject PDU reason=%d\n", reason);
240 
241 	if (conn->sess != NULL) {
242 		SPDK_DEBUGLOG(iscsi,
243 			      "StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
244 			      conn->StatSN, conn->sess->ExpCmdSN,
245 			      conn->sess->MaxCmdSN);
246 	} else {
247 		SPDK_DEBUGLOG(iscsi, "StatSN=%u\n", conn->StatSN);
248 	}
249 
250 	memcpy(data, &pdu->bhs, ISCSI_BHS_LEN);
251 	data_len += ISCSI_BHS_LEN;
252 
253 	if (total_ahs_len != 0) {
254 		total_ahs_len = spdk_min((4 * total_ahs_len), ISCSI_AHS_LEN);
255 		memcpy(data + data_len, pdu->ahs, total_ahs_len);
256 		data_len += total_ahs_len;
257 	}
258 
259 	if (conn->header_digest) {
260 		memcpy(data + data_len, pdu->header_digest, ISCSI_DIGEST_LEN);
261 		data_len += ISCSI_DIGEST_LEN;
262 	}
263 
264 	rsp_pdu = iscsi_get_pdu(conn);
265 	if (rsp_pdu == NULL) {
266 		free(data);
267 		return -ENOMEM;
268 	}
269 
270 	rsph = (struct iscsi_bhs_reject *)&rsp_pdu->bhs;
271 	rsp_pdu->data = data;
272 	rsph->opcode = ISCSI_OP_REJECT;
273 	rsph->flags |= 0x80;	/* bit 0 is default to 1 */
274 	rsph->reason = reason;
275 	DSET24(rsph->data_segment_len, data_len);
276 
277 	rsph->ffffffff = 0xffffffffU;
278 	to_be32(&rsph->stat_sn, conn->StatSN);
279 	conn->StatSN++;
280 
281 	if (conn->sess != NULL) {
282 		to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
283 		to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
284 	} else {
285 		to_be32(&rsph->exp_cmd_sn, 1);
286 		to_be32(&rsph->max_cmd_sn, 1);
287 	}
288 
289 	SPDK_LOGDUMP(iscsi, "PDU", (void *)&rsp_pdu->bhs, ISCSI_BHS_LEN);
290 
291 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_pdu_generic_complete, NULL);
292 
293 	return 0;
294 }
295 
296 uint32_t
297 iscsi_pdu_calc_header_digest(struct spdk_iscsi_pdu *pdu)
298 {
299 	uint32_t crc32c;
300 	uint32_t ahs_len_bytes = pdu->bhs.total_ahs_len * 4;
301 
302 	crc32c = SPDK_CRC32C_INITIAL;
303 	crc32c = spdk_crc32c_update(&pdu->bhs, ISCSI_BHS_LEN, crc32c);
304 
305 	if (ahs_len_bytes) {
306 		crc32c = spdk_crc32c_update(pdu->ahs, ahs_len_bytes, crc32c);
307 	}
308 
309 	/* BHS and AHS are always 4-byte multiples in length, so no padding is necessary. */
310 	crc32c = crc32c ^ SPDK_CRC32C_XOR;
311 	return crc32c;
312 }
313 
314 uint32_t
315 iscsi_pdu_calc_data_digest(struct spdk_iscsi_pdu *pdu)
316 {
317 	uint32_t data_len = DGET24(pdu->bhs.data_segment_len);
318 	uint32_t crc32c;
319 	uint32_t mod;
320 	struct iovec iov;
321 	uint32_t num_blocks;
322 
323 	crc32c = SPDK_CRC32C_INITIAL;
324 	if (spdk_likely(!pdu->dif_insert_or_strip)) {
325 		crc32c = spdk_crc32c_update(pdu->data, data_len, crc32c);
326 	} else {
327 		iov.iov_base = pdu->data_buf;
328 		iov.iov_len = pdu->data_buf_len;
329 		num_blocks = pdu->data_buf_len / pdu->dif_ctx.block_size;
330 
331 		spdk_dif_update_crc32c(&iov, 1, num_blocks, &crc32c, &pdu->dif_ctx);
332 	}
333 
334 	mod = data_len % ISCSI_ALIGNMENT;
335 	if (mod != 0) {
336 		uint32_t pad_length = ISCSI_ALIGNMENT - mod;
337 		uint8_t pad[3] = {0, 0, 0};
338 
339 		assert(pad_length > 0);
340 		assert(pad_length <= sizeof(pad));
341 		crc32c = spdk_crc32c_update(pad, pad_length, crc32c);
342 	}
343 
344 	crc32c = crc32c ^ SPDK_CRC32C_XOR;
345 	return crc32c;
346 }
347 
348 static int
349 iscsi_conn_read_data_segment(struct spdk_iscsi_conn *conn,
350 			     struct spdk_iscsi_pdu *pdu,
351 			     uint32_t segment_len)
352 {
353 	struct iovec buf_iov, iovs[32];
354 	int rc, _rc;
355 
356 	if (spdk_likely(!pdu->dif_insert_or_strip)) {
357 		return iscsi_conn_read_data(conn,
358 					    segment_len - pdu->data_valid_bytes,
359 					    pdu->data_buf + pdu->data_valid_bytes);
360 	} else {
361 		buf_iov.iov_base = pdu->data_buf;
362 		buf_iov.iov_len = pdu->data_buf_len;
363 		rc = spdk_dif_set_md_interleave_iovs(iovs, 32, &buf_iov, 1,
364 						     pdu->data_valid_bytes,
365 						     segment_len - pdu->data_valid_bytes, NULL,
366 						     &pdu->dif_ctx);
367 		if (rc > 0) {
368 			rc = iscsi_conn_readv_data(conn, iovs, rc);
369 			if (rc > 0) {
370 				_rc = spdk_dif_generate_stream(&buf_iov, 1,
371 							       pdu->data_valid_bytes, rc,
372 							       &pdu->dif_ctx);
373 				if (_rc != 0) {
374 					SPDK_ERRLOG("DIF generate failed\n");
375 					rc = _rc;
376 				}
377 			}
378 		} else {
379 			SPDK_ERRLOG("Setup iovs for interleaved metadata failed\n");
380 		}
381 		return rc;
382 	}
383 }
384 
385 struct _iscsi_sgl {
386 	struct iovec	*iov;
387 	int		iovcnt;
388 	uint32_t	iov_offset;
389 	uint32_t	total_size;
390 };
391 
392 static inline void
393 _iscsi_sgl_init(struct _iscsi_sgl *s, struct iovec *iovs, int iovcnt,
394 		uint32_t iov_offset)
395 {
396 	s->iov = iovs;
397 	s->iovcnt = iovcnt;
398 	s->iov_offset = iov_offset;
399 	s->total_size = 0;
400 }
401 
402 static inline bool
403 _iscsi_sgl_append(struct _iscsi_sgl *s, uint8_t *data, uint32_t data_len)
404 {
405 	if (s->iov_offset >= data_len) {
406 		s->iov_offset -= data_len;
407 	} else {
408 		assert(s->iovcnt > 0);
409 		s->iov->iov_base = data + s->iov_offset;
410 		s->iov->iov_len = data_len - s->iov_offset;
411 		s->total_size += data_len - s->iov_offset;
412 		s->iov_offset = 0;
413 		s->iov++;
414 		s->iovcnt--;
415 		if (s->iovcnt == 0) {
416 			return false;
417 		}
418 	}
419 
420 	return true;
421 }
422 
423 /* Build iovec array to leave metadata space for every data block
424  * when reading data segment from socket.
425  */
426 static inline bool
427 _iscsi_sgl_append_with_md(struct _iscsi_sgl *s,
428 			  void *buf, uint32_t buf_len, uint32_t data_len,
429 			  struct spdk_dif_ctx *dif_ctx)
430 {
431 	int rc;
432 	uint32_t total_size = 0;
433 	struct iovec buf_iov;
434 
435 	if (s->iov_offset >= data_len) {
436 		s->iov_offset -= data_len;
437 	} else {
438 		buf_iov.iov_base = buf;
439 		buf_iov.iov_len = buf_len;
440 		rc = spdk_dif_set_md_interleave_iovs(s->iov, s->iovcnt, &buf_iov, 1,
441 						     s->iov_offset, data_len - s->iov_offset,
442 						     &total_size, dif_ctx);
443 		if (rc < 0) {
444 			SPDK_ERRLOG("Failed to setup iovs for DIF strip\n");
445 			return false;
446 		}
447 
448 		s->total_size += total_size;
449 		s->iov_offset = 0;
450 		assert(s->iovcnt >= rc);
451 		s->iovcnt -= rc;
452 		s->iov += rc;
453 
454 		if (s->iovcnt == 0) {
455 			return false;
456 		}
457 	}
458 
459 	return true;
460 }
461 
462 int
463 iscsi_build_iovs(struct spdk_iscsi_conn *conn, struct iovec *iovs, int iovcnt,
464 		 struct spdk_iscsi_pdu *pdu, uint32_t *_mapped_length)
465 {
466 	struct _iscsi_sgl sgl;
467 	int enable_digest;
468 	uint32_t total_ahs_len;
469 	uint32_t data_len;
470 
471 	if (iovcnt == 0) {
472 		return 0;
473 	}
474 
475 	total_ahs_len = pdu->bhs.total_ahs_len;
476 	data_len = DGET24(pdu->bhs.data_segment_len);
477 	data_len = ISCSI_ALIGN(data_len);
478 
479 	enable_digest = 1;
480 	if (pdu->bhs.opcode == ISCSI_OP_LOGIN_RSP) {
481 		/* this PDU should be sent without digest */
482 		enable_digest = 0;
483 	}
484 
485 	_iscsi_sgl_init(&sgl, iovs, iovcnt, pdu->writev_offset);
486 
487 	/* BHS */
488 	if (!_iscsi_sgl_append(&sgl, (uint8_t *)&pdu->bhs, ISCSI_BHS_LEN)) {
489 		goto end;
490 	}
491 	/* AHS */
492 	if (total_ahs_len > 0) {
493 		if (!_iscsi_sgl_append(&sgl, pdu->ahs, 4 * total_ahs_len)) {
494 			goto end;
495 		}
496 	}
497 
498 	/* Header Digest */
499 	if (enable_digest && conn->header_digest) {
500 		if (!_iscsi_sgl_append(&sgl, pdu->header_digest, ISCSI_DIGEST_LEN)) {
501 			goto end;
502 		}
503 	}
504 
505 	/* Data Segment */
506 	if (data_len > 0) {
507 		if (!pdu->dif_insert_or_strip) {
508 			if (!_iscsi_sgl_append(&sgl, pdu->data, data_len)) {
509 				goto end;
510 			}
511 		} else {
512 			if (!_iscsi_sgl_append_with_md(&sgl, pdu->data, pdu->data_buf_len,
513 						       data_len, &pdu->dif_ctx)) {
514 				goto end;
515 			}
516 		}
517 	}
518 
519 	/* Data Digest */
520 	if (enable_digest && conn->data_digest && data_len != 0) {
521 		_iscsi_sgl_append(&sgl, pdu->data_digest, ISCSI_DIGEST_LEN);
522 	}
523 
524 end:
525 	if (_mapped_length != NULL) {
526 		*_mapped_length = sgl.total_size;
527 	}
528 
529 	return iovcnt - sgl.iovcnt;
530 }
531 
532 void iscsi_free_sess(struct spdk_iscsi_sess *sess)
533 {
534 	if (sess == NULL) {
535 		return;
536 	}
537 
538 	sess->tag = 0;
539 	sess->target = NULL;
540 	sess->session_type = SESSION_TYPE_INVALID;
541 	iscsi_param_free(sess->params);
542 	free(sess->conns);
543 	spdk_scsi_port_free(&sess->initiator_port);
544 	spdk_mempool_put(g_iscsi.session_pool, (void *)sess);
545 }
546 
547 static int
548 create_iscsi_sess(struct spdk_iscsi_conn *conn,
549 		  struct spdk_iscsi_tgt_node *target,
550 		  enum session_type session_type)
551 {
552 	struct spdk_iscsi_sess *sess;
553 	int rc;
554 
555 	sess = spdk_mempool_get(g_iscsi.session_pool);
556 	if (!sess) {
557 		SPDK_ERRLOG("Unable to get session object\n");
558 		SPDK_ERRLOG("MaxSessions set to %d\n", g_iscsi.MaxSessions);
559 		return -ENOMEM;
560 	}
561 
562 	/* configuration values */
563 	pthread_mutex_lock(&g_iscsi.mutex);
564 
565 	sess->MaxConnections = g_iscsi.MaxConnectionsPerSession;
566 	sess->MaxOutstandingR2T = DEFAULT_MAXOUTSTANDINGR2T;
567 
568 	sess->DefaultTime2Wait = g_iscsi.DefaultTime2Wait;
569 	sess->DefaultTime2Retain = g_iscsi.DefaultTime2Retain;
570 	sess->FirstBurstLength = g_iscsi.FirstBurstLength;
571 	sess->MaxBurstLength = SPDK_ISCSI_MAX_BURST_LENGTH;
572 	sess->InitialR2T = DEFAULT_INITIALR2T;
573 	sess->ImmediateData = g_iscsi.ImmediateData;
574 	sess->DataPDUInOrder = DEFAULT_DATAPDUINORDER;
575 	sess->DataSequenceInOrder = DEFAULT_DATASEQUENCEINORDER;
576 	sess->ErrorRecoveryLevel = g_iscsi.ErrorRecoveryLevel;
577 
578 	pthread_mutex_unlock(&g_iscsi.mutex);
579 
580 	sess->tag = conn->pg_tag;
581 
582 	sess->conns = calloc(sess->MaxConnections, sizeof(*sess->conns));
583 	if (!sess->conns) {
584 		SPDK_ERRLOG("calloc() failed for connection array\n");
585 		return -ENOMEM;
586 	}
587 
588 	sess->connections = 0;
589 
590 	sess->conns[sess->connections] = conn;
591 	sess->connections++;
592 
593 	sess->params = NULL;
594 	sess->target = target;
595 	sess->isid = 0;
596 	sess->session_type = session_type;
597 	sess->current_text_itt = 0xffffffffU;
598 
599 	/* set default params */
600 	rc = iscsi_sess_params_init(&sess->params);
601 	if (rc < 0) {
602 		SPDK_ERRLOG("iscsi_sess_params_init() failed\n");
603 		goto error_return;
604 	}
605 	/* replace with config value */
606 	rc = iscsi_param_set_int(sess->params, "MaxConnections",
607 				 sess->MaxConnections);
608 	if (rc < 0) {
609 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
610 		goto error_return;
611 	}
612 
613 	rc = iscsi_param_set_int(sess->params, "MaxOutstandingR2T",
614 				 sess->MaxOutstandingR2T);
615 	if (rc < 0) {
616 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
617 		goto error_return;
618 	}
619 
620 	rc = iscsi_param_set_int(sess->params, "DefaultTime2Wait",
621 				 sess->DefaultTime2Wait);
622 	if (rc < 0) {
623 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
624 		goto error_return;
625 	}
626 
627 	rc = iscsi_param_set_int(sess->params, "DefaultTime2Retain",
628 				 sess->DefaultTime2Retain);
629 	if (rc < 0) {
630 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
631 		goto error_return;
632 	}
633 
634 	rc = iscsi_param_set_int(sess->params, "FirstBurstLength",
635 				 sess->FirstBurstLength);
636 	if (rc < 0) {
637 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
638 		goto error_return;
639 	}
640 
641 	rc = iscsi_param_set_int(sess->params, "MaxBurstLength",
642 				 sess->MaxBurstLength);
643 	if (rc < 0) {
644 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
645 		goto error_return;
646 	}
647 
648 	rc = iscsi_param_set(sess->params, "InitialR2T",
649 			     sess->InitialR2T ? "Yes" : "No");
650 	if (rc < 0) {
651 		SPDK_ERRLOG("iscsi_param_set() failed\n");
652 		goto error_return;
653 	}
654 
655 	rc = iscsi_param_set(sess->params, "ImmediateData",
656 			     sess->ImmediateData ? "Yes" : "No");
657 	if (rc < 0) {
658 		SPDK_ERRLOG("iscsi_param_set() failed\n");
659 		goto error_return;
660 	}
661 
662 	rc = iscsi_param_set(sess->params, "DataPDUInOrder",
663 			     sess->DataPDUInOrder ? "Yes" : "No");
664 	if (rc < 0) {
665 		SPDK_ERRLOG("iscsi_param_set() failed\n");
666 		goto error_return;
667 	}
668 
669 	rc = iscsi_param_set(sess->params, "DataSequenceInOrder",
670 			     sess->DataSequenceInOrder ? "Yes" : "No");
671 	if (rc < 0) {
672 		SPDK_ERRLOG("iscsi_param_set() failed\n");
673 		goto error_return;
674 	}
675 
676 	rc = iscsi_param_set_int(sess->params, "ErrorRecoveryLevel",
677 				 sess->ErrorRecoveryLevel);
678 	if (rc < 0) {
679 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
680 		goto error_return;
681 	}
682 
683 	/* realloc buffer */
684 	rc = iscsi_param_set_int(conn->params, "MaxRecvDataSegmentLength",
685 				 conn->MaxRecvDataSegmentLength);
686 	if (rc < 0) {
687 		SPDK_ERRLOG("iscsi_param_set_int() failed\n");
688 		goto error_return;
689 	}
690 
691 	/* sess for first connection of session */
692 	conn->sess = sess;
693 	return 0;
694 
695 error_return:
696 	iscsi_free_sess(sess);
697 	conn->sess = NULL;
698 	return -1;
699 }
700 
701 static struct spdk_iscsi_sess *
702 get_iscsi_sess_by_tsih(uint16_t tsih)
703 {
704 	struct spdk_iscsi_sess *session;
705 
706 	if (tsih == 0 || tsih > g_iscsi.MaxSessions) {
707 		return NULL;
708 	}
709 
710 	session = g_iscsi.session[tsih - 1];
711 	assert(tsih == session->tsih);
712 
713 	return session;
714 }
715 
716 static uint8_t
717 append_iscsi_sess(struct spdk_iscsi_conn *conn,
718 		  const char *initiator_port_name, uint16_t tsih, uint16_t cid)
719 {
720 	struct spdk_iscsi_sess *sess;
721 
722 	SPDK_DEBUGLOG(iscsi, "append session: init port name=%s, tsih=%u, cid=%u\n",
723 		      initiator_port_name, tsih, cid);
724 
725 	sess = get_iscsi_sess_by_tsih(tsih);
726 	if (sess == NULL) {
727 		SPDK_ERRLOG("spdk_get_iscsi_sess_by_tsih failed\n");
728 		return ISCSI_LOGIN_CONN_ADD_FAIL;
729 	}
730 	if ((conn->pg_tag != sess->tag) ||
731 	    (strcasecmp(initiator_port_name, spdk_scsi_port_get_name(sess->initiator_port)) != 0) ||
732 	    (conn->target != sess->target)) {
733 		/* no match */
734 		SPDK_ERRLOG("no MCS session for init port name=%s, tsih=%d, cid=%d\n",
735 			    initiator_port_name, tsih, cid);
736 		return ISCSI_LOGIN_CONN_ADD_FAIL;
737 	}
738 
739 	if (sess->connections >= sess->MaxConnections) {
740 		/* no slot for connection */
741 		SPDK_ERRLOG("too many connections for init port name=%s, tsih=%d, cid=%d\n",
742 			    initiator_port_name, tsih, cid);
743 		return ISCSI_LOGIN_TOO_MANY_CONNECTIONS;
744 	}
745 
746 	SPDK_DEBUGLOG(iscsi, "Connections (tsih %d): %d\n", sess->tsih, sess->connections);
747 	conn->sess = sess;
748 
749 	/*
750 	 * TODO: need a mutex or other sync mechanism to protect the session's
751 	 *  connection list.
752 	 */
753 	sess->conns[sess->connections] = conn;
754 	sess->connections++;
755 
756 	return 0;
757 }
758 
759 static int
760 iscsi_append_text(const char *key, const char *val, uint8_t *data,
761 		  int alloc_len, int data_len)
762 {
763 	int total;
764 	int len;
765 
766 	total = data_len;
767 	if (alloc_len < 1) {
768 		return 0;
769 	}
770 	if (total > alloc_len) {
771 		total = alloc_len;
772 		data[total - 1] = '\0';
773 		return total;
774 	}
775 
776 	if (alloc_len - total < 1) {
777 		SPDK_ERRLOG("data space small %d\n", alloc_len);
778 		return total;
779 	}
780 	len = snprintf((char *) data + total, alloc_len - total, "%s=%s", key, val);
781 	total += len + 1;
782 
783 	return total;
784 }
785 
786 static int
787 iscsi_append_param(struct spdk_iscsi_conn *conn, const char *key,
788 		   uint8_t *data, int alloc_len, int data_len)
789 {
790 	struct iscsi_param *param;
791 
792 	param = iscsi_param_find(conn->params, key);
793 	if (param == NULL) {
794 		param = iscsi_param_find(conn->sess->params, key);
795 		if (param == NULL) {
796 			SPDK_DEBUGLOG(iscsi, "no key %.64s\n", key);
797 			return data_len;
798 		}
799 	}
800 	return iscsi_append_text(param->key, param->val, data,
801 				 alloc_len, data_len);
802 }
803 
804 static int
805 iscsi_auth_params(struct spdk_iscsi_conn *conn,
806 		  struct iscsi_param *params, const char *method, uint8_t *data,
807 		  int alloc_len, int data_len)
808 {
809 	char *in_val;
810 	char *in_next;
811 	char *new_val;
812 	const char *algorithm;
813 	const char *name;
814 	const char *response;
815 	const char *identifier;
816 	const char *challenge;
817 	int total;
818 	int rc;
819 
820 	if (conn == NULL || params == NULL || method == NULL) {
821 		return -1;
822 	}
823 	if (strcasecmp(method, "CHAP") == 0) {
824 		/* method OK */
825 	} else {
826 		SPDK_ERRLOG("unsupported AuthMethod %.64s\n", method);
827 		return -1;
828 	}
829 
830 	total = data_len;
831 	if (alloc_len < 1) {
832 		return 0;
833 	}
834 	if (total > alloc_len) {
835 		total = alloc_len;
836 		data[total - 1] = '\0';
837 		return total;
838 	}
839 
840 	/* for temporary store */
841 	in_val = malloc(ISCSI_TEXT_MAX_VAL_LEN + 1);
842 	if (!in_val) {
843 		SPDK_ERRLOG("malloc() failed for temporary store\n");
844 		return -ENOMEM;
845 	}
846 
847 	/* CHAP method (RFC1994) */
848 	if ((algorithm = iscsi_param_get_val(params, "CHAP_A")) != NULL) {
849 		if (conn->auth.chap_phase != ISCSI_CHAP_PHASE_WAIT_A) {
850 			SPDK_ERRLOG("CHAP sequence error\n");
851 			goto error_return;
852 		}
853 
854 		/* CHAP_A is LIST type */
855 		snprintf(in_val, ISCSI_TEXT_MAX_VAL_LEN + 1, "%s", algorithm);
856 		in_next = in_val;
857 		while ((new_val = spdk_strsepq(&in_next, ",")) != NULL) {
858 			if (strcasecmp(new_val, "5") == 0) {
859 				/* CHAP with MD5 */
860 				break;
861 			}
862 		}
863 		if (new_val == NULL) {
864 			snprintf(in_val, ISCSI_TEXT_MAX_VAL_LEN + 1, "%s", "Reject");
865 			new_val = in_val;
866 			iscsi_append_text("CHAP_A", new_val, data, alloc_len, total);
867 			goto error_return;
868 		}
869 		/* selected algorithm is 5 (MD5) */
870 		SPDK_DEBUGLOG(iscsi, "got CHAP_A=%s\n", new_val);
871 		total = iscsi_append_text("CHAP_A", new_val, data, alloc_len, total);
872 
873 		/* Identifier is one octet */
874 		gen_random(conn->auth.chap_id, 1);
875 		snprintf(in_val, ISCSI_TEXT_MAX_VAL_LEN, "%d",
876 			 (int) conn->auth.chap_id[0]);
877 		total = iscsi_append_text("CHAP_I", in_val, data, alloc_len, total);
878 
879 		/* Challenge Value is a variable stream of octets */
880 		/* (binary length MUST not exceed 1024 bytes) */
881 		conn->auth.chap_challenge_len = ISCSI_CHAP_CHALLENGE_LEN;
882 		gen_random(conn->auth.chap_challenge, conn->auth.chap_challenge_len);
883 		bin2hex(in_val, ISCSI_TEXT_MAX_VAL_LEN,
884 			conn->auth.chap_challenge, conn->auth.chap_challenge_len);
885 		total = iscsi_append_text("CHAP_C", in_val, data, alloc_len, total);
886 
887 		conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_NR;
888 	} else if ((name = iscsi_param_get_val(params, "CHAP_N")) != NULL) {
889 		uint8_t resmd5[SPDK_MD5DIGEST_LEN];
890 		uint8_t tgtmd5[SPDK_MD5DIGEST_LEN];
891 		struct spdk_md5ctx md5ctx;
892 		size_t decoded_len = 0;
893 
894 		if (conn->auth.chap_phase != ISCSI_CHAP_PHASE_WAIT_NR) {
895 			SPDK_ERRLOG("CHAP sequence error\n");
896 			goto error_return;
897 		}
898 
899 		response = iscsi_param_get_val(params, "CHAP_R");
900 		if (response == NULL) {
901 			SPDK_ERRLOG("no response\n");
902 			goto error_return;
903 		}
904 		if (response[0] == '0' &&
905 		    (response[1] == 'x' || response[1] == 'X')) {
906 			rc = hex2bin(resmd5, SPDK_MD5DIGEST_LEN, response);
907 			if (rc < 0 || rc != SPDK_MD5DIGEST_LEN) {
908 				SPDK_ERRLOG("response format error\n");
909 				goto error_return;
910 			}
911 		} else if (response[0] == '0' &&
912 			   (response[1] == 'b' || response[1] == 'B')) {
913 			response += 2;
914 			rc = spdk_base64_decode(resmd5, &decoded_len, response);
915 			if (rc < 0 || decoded_len != SPDK_MD5DIGEST_LEN) {
916 				SPDK_ERRLOG("response format error\n");
917 				goto error_return;
918 			}
919 		} else {
920 			SPDK_ERRLOG("response format error\n");
921 			goto error_return;
922 		}
923 		SPDK_DEBUGLOG(iscsi, "got CHAP_N/CHAP_R\n");
924 
925 		SPDK_DEBUGLOG(iscsi, "ag_tag=%d\n", conn->chap_group);
926 
927 		rc = iscsi_chap_get_authinfo(&conn->auth, name, conn->chap_group);
928 		if (rc < 0) {
929 			/* SPDK_ERRLOG("auth user or secret is missing\n"); */
930 			SPDK_ERRLOG("iscsi_chap_get_authinfo() failed\n");
931 			goto error_return;
932 		}
933 		if (conn->auth.user[0] == '\0' || conn->auth.secret[0] == '\0') {
934 			/* SPDK_ERRLOG("auth user or secret is missing\n"); */
935 			SPDK_ERRLOG("auth failed (name %.64s)\n", name);
936 			goto error_return;
937 		}
938 
939 		md5init(&md5ctx);
940 		/* Identifier */
941 		md5update(&md5ctx, conn->auth.chap_id, 1);
942 		/* followed by secret */
943 		md5update(&md5ctx, conn->auth.secret,
944 			  strlen(conn->auth.secret));
945 		/* followed by Challenge Value */
946 		md5update(&md5ctx, conn->auth.chap_challenge,
947 			  conn->auth.chap_challenge_len);
948 		/* tgtmd5 is expecting Response Value */
949 		md5final(tgtmd5, &md5ctx);
950 
951 		bin2hex(in_val, ISCSI_TEXT_MAX_VAL_LEN, tgtmd5, SPDK_MD5DIGEST_LEN);
952 
953 #if 0
954 		SPDK_DEBUGLOG(iscsi, "tgtmd5=%s, resmd5=%s\n", in_val, response);
955 		spdk_dump("tgtmd5", tgtmd5, SPDK_MD5DIGEST_LEN);
956 		spdk_dump("resmd5", resmd5, SPDK_MD5DIGEST_LEN);
957 #endif
958 
959 		/* compare MD5 digest */
960 		if (memcmp(tgtmd5, resmd5, SPDK_MD5DIGEST_LEN) != 0) {
961 			/* not match */
962 			/* SPDK_ERRLOG("auth user or secret is missing\n"); */
963 			SPDK_ERRLOG("auth failed (name %.64s)\n", name);
964 			goto error_return;
965 		}
966 		/* OK initiator's secret */
967 		conn->authenticated = true;
968 
969 		/* mutual CHAP? */
970 		identifier = iscsi_param_get_val(params, "CHAP_I");
971 		if (identifier != NULL) {
972 			conn->auth.chap_mid[0] = (uint8_t) strtol(identifier, NULL, 10);
973 			challenge = iscsi_param_get_val(params, "CHAP_C");
974 			if (challenge == NULL) {
975 				SPDK_ERRLOG("CHAP sequence error\n");
976 				goto error_return;
977 			}
978 			if (challenge[0] == '0' &&
979 			    (challenge[1] == 'x' || challenge[1] == 'X')) {
980 				rc = hex2bin(conn->auth.chap_mchallenge,
981 					     ISCSI_CHAP_CHALLENGE_LEN, challenge);
982 				if (rc < 0) {
983 					SPDK_ERRLOG("challenge format error\n");
984 					goto error_return;
985 				}
986 				conn->auth.chap_mchallenge_len = rc;
987 			} else if (challenge[0] == '0' &&
988 				   (challenge[1] == 'b' || challenge[1] == 'B')) {
989 				challenge += 2;
990 				rc = spdk_base64_decode(conn->auth.chap_mchallenge,
991 							&decoded_len, challenge);
992 				if (rc < 0) {
993 					SPDK_ERRLOG("challenge format error\n");
994 					goto error_return;
995 				}
996 				conn->auth.chap_mchallenge_len = decoded_len;
997 			} else {
998 				SPDK_ERRLOG("challenge format error\n");
999 				goto error_return;
1000 			}
1001 #if 0
1002 			spdk_dump("MChallenge", conn->auth.chap_mchallenge,
1003 				  conn->auth.chap_mchallenge_len);
1004 #endif
1005 			SPDK_DEBUGLOG(iscsi, "got CHAP_I/CHAP_C\n");
1006 
1007 			if (conn->auth.muser[0] == '\0' || conn->auth.msecret[0] == '\0') {
1008 				/* SPDK_ERRLOG("mutual auth user or secret is missing\n"); */
1009 				SPDK_ERRLOG("auth failed (name %.64s)\n", name);
1010 				goto error_return;
1011 			}
1012 
1013 			md5init(&md5ctx);
1014 			/* Identifier */
1015 			md5update(&md5ctx, conn->auth.chap_mid, 1);
1016 			/* followed by secret */
1017 			md5update(&md5ctx, conn->auth.msecret,
1018 				  strlen(conn->auth.msecret));
1019 			/* followed by Challenge Value */
1020 			md5update(&md5ctx, conn->auth.chap_mchallenge,
1021 				  conn->auth.chap_mchallenge_len);
1022 			/* tgtmd5 is Response Value */
1023 			md5final(tgtmd5, &md5ctx);
1024 
1025 			bin2hex(in_val, ISCSI_TEXT_MAX_VAL_LEN, tgtmd5, SPDK_MD5DIGEST_LEN);
1026 
1027 			total = iscsi_append_text("CHAP_N", conn->auth.muser, data,
1028 						  alloc_len, total);
1029 			total = iscsi_append_text("CHAP_R", in_val, data, alloc_len, total);
1030 		} else {
1031 			/* not mutual */
1032 			if (conn->mutual_chap) {
1033 				SPDK_ERRLOG("required mutual CHAP\n");
1034 				goto error_return;
1035 			}
1036 		}
1037 
1038 		conn->auth.chap_phase = ISCSI_CHAP_PHASE_END;
1039 	} else {
1040 		/* not found CHAP keys */
1041 		SPDK_DEBUGLOG(iscsi, "start CHAP\n");
1042 		conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_A;
1043 	}
1044 
1045 	free(in_val);
1046 	return total;
1047 
1048 error_return:
1049 	conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_A;
1050 	free(in_val);
1051 	return -1;
1052 }
1053 
1054 static int
1055 iscsi_check_values(struct spdk_iscsi_conn *conn)
1056 {
1057 	if (conn->sess->FirstBurstLength > conn->sess->MaxBurstLength) {
1058 		SPDK_ERRLOG("FirstBurstLength(%d) > MaxBurstLength(%d)\n",
1059 			    conn->sess->FirstBurstLength,
1060 			    conn->sess->MaxBurstLength);
1061 		return -1;
1062 	}
1063 	if (conn->sess->FirstBurstLength > g_iscsi.FirstBurstLength) {
1064 		SPDK_ERRLOG("FirstBurstLength(%d) > iSCSI target restriction(%d)\n",
1065 			    conn->sess->FirstBurstLength, g_iscsi.FirstBurstLength);
1066 		return -1;
1067 	}
1068 	if (conn->sess->MaxBurstLength > 0x00ffffff) {
1069 		SPDK_ERRLOG("MaxBurstLength(%d) > 0x00ffffff\n",
1070 			    conn->sess->MaxBurstLength);
1071 		return -1;
1072 	}
1073 
1074 	if (conn->MaxRecvDataSegmentLength < 512) {
1075 		SPDK_ERRLOG("MaxRecvDataSegmentLength(%d) < 512\n",
1076 			    conn->MaxRecvDataSegmentLength);
1077 		return -1;
1078 	}
1079 	if (conn->MaxRecvDataSegmentLength > 0x00ffffff) {
1080 		SPDK_ERRLOG("MaxRecvDataSegmentLength(%d) > 0x00ffffff\n",
1081 			    conn->MaxRecvDataSegmentLength);
1082 		return -1;
1083 	}
1084 	return 0;
1085 }
1086 
1087 static int
1088 iscsi_conn_params_update(struct spdk_iscsi_conn *conn)
1089 {
1090 	int rc;
1091 	uint32_t recv_buf_size;
1092 
1093 	/* update internal variables */
1094 	rc = iscsi_copy_param2var(conn);
1095 	if (rc < 0) {
1096 		SPDK_ERRLOG("iscsi_copy_param2var() failed\n");
1097 		if (conn->state < ISCSI_CONN_STATE_EXITING) {
1098 			conn->state = ISCSI_CONN_STATE_EXITING;
1099 		}
1100 		return rc;
1101 	}
1102 
1103 	/* check value */
1104 	rc = iscsi_check_values(conn);
1105 	if (rc < 0) {
1106 		SPDK_ERRLOG("iscsi_check_values() failed\n");
1107 		if (conn->state < ISCSI_CONN_STATE_EXITING) {
1108 			conn->state = ISCSI_CONN_STATE_EXITING;
1109 		}
1110 	}
1111 
1112 	/* The socket receive buffer may need to be adjusted based on the new parameters */
1113 
1114 	/* Don't allow the recv buffer to be 0 or very large. */
1115 	recv_buf_size = spdk_max(0x1000, spdk_min(0x2000, conn->sess->FirstBurstLength));
1116 
1117 	/* Add in extra space for the PDU */
1118 	recv_buf_size += ISCSI_BHS_LEN + ISCSI_AHS_LEN;
1119 
1120 	if (conn->header_digest) {
1121 		recv_buf_size += ISCSI_DIGEST_LEN;
1122 	}
1123 
1124 	if (conn->data_digest) {
1125 		recv_buf_size += ISCSI_DIGEST_LEN;
1126 	}
1127 
1128 	/* Set up to buffer up to 4 commands with immediate data at once */
1129 	if (spdk_sock_set_recvbuf(conn->sock, recv_buf_size * 4) < 0) {
1130 		/* Not fatal. */
1131 	}
1132 
1133 	return rc;
1134 }
1135 
1136 static void
1137 iscsi_conn_login_pdu_err_complete(void *arg)
1138 {
1139 	struct spdk_iscsi_conn *conn = arg;
1140 
1141 	if (conn->full_feature) {
1142 		iscsi_conn_params_update(conn);
1143 	}
1144 }
1145 
1146 static void
1147 iscsi_conn_login_pdu_success_complete(void *arg)
1148 {
1149 	struct spdk_iscsi_conn *conn = arg;
1150 
1151 	if (conn->state >= ISCSI_CONN_STATE_EXITING) {
1152 		/* Connection is being exited before this callback is executed. */
1153 		SPDK_DEBUGLOG(iscsi, "Connection is already exited.\n");
1154 		return;
1155 	}
1156 	if (conn->full_feature) {
1157 		if (iscsi_conn_params_update(conn) != 0) {
1158 			return;
1159 		}
1160 	}
1161 	conn->state = ISCSI_CONN_STATE_RUNNING;
1162 	if (conn->full_feature != 0) {
1163 		iscsi_conn_schedule(conn);
1164 	}
1165 }
1166 
1167 /*
1168  * The response function of spdk_iscsi_op_login
1169  */
1170 static void
1171 iscsi_op_login_response(struct spdk_iscsi_conn *conn,
1172 			struct spdk_iscsi_pdu *rsp_pdu, struct iscsi_param *params,
1173 			iscsi_conn_xfer_complete_cb cb_fn)
1174 {
1175 	struct iscsi_bhs_login_rsp *rsph;
1176 
1177 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1178 	rsph->version_max = ISCSI_VERSION;
1179 	rsph->version_act = ISCSI_VERSION;
1180 	DSET24(rsph->data_segment_len, rsp_pdu->data_segment_len);
1181 
1182 	to_be32(&rsph->stat_sn, conn->StatSN);
1183 	conn->StatSN++;
1184 
1185 	if (conn->sess != NULL) {
1186 		to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
1187 		to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
1188 	} else {
1189 		to_be32(&rsph->exp_cmd_sn, rsp_pdu->cmd_sn);
1190 		to_be32(&rsph->max_cmd_sn, rsp_pdu->cmd_sn);
1191 	}
1192 
1193 	SPDK_LOGDUMP(iscsi, "PDU", (uint8_t *)rsph, ISCSI_BHS_LEN);
1194 	SPDK_LOGDUMP(iscsi, "DATA", rsp_pdu->data, rsp_pdu->data_segment_len);
1195 
1196 	/* Set T/CSG/NSG to reserved if login error. */
1197 	if (rsph->status_class != 0) {
1198 		rsph->flags &= ~(ISCSI_LOGIN_TRANSIT | ISCSI_LOGIN_CURRENT_STAGE_MASK |
1199 				 ISCSI_LOGIN_NEXT_STAGE_MASK);
1200 	}
1201 	iscsi_param_free(params);
1202 	iscsi_conn_write_pdu(conn, rsp_pdu, cb_fn, conn);
1203 }
1204 
1205 /*
1206  * The function which is used to initialize the internal response data
1207  * structure of iscsi login function.
1208  * return:
1209  * 0, success;
1210  * otherwise, error;
1211  */
1212 static int
1213 iscsi_op_login_rsp_init(struct spdk_iscsi_conn *conn,
1214 			struct spdk_iscsi_pdu *pdu, struct spdk_iscsi_pdu *rsp_pdu)
1215 {
1216 	struct iscsi_bhs_login_req *reqh;
1217 	struct iscsi_bhs_login_rsp *rsph;
1218 
1219 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1220 	rsph->opcode = ISCSI_OP_LOGIN_RSP;
1221 	rsph->status_class = ISCSI_CLASS_SUCCESS;
1222 	rsph->status_detail = ISCSI_LOGIN_ACCEPT;
1223 	rsp_pdu->data_segment_len = 0;
1224 
1225 	/* The default MaxRecvDataSegmentLength 8192 is used during login. - RFC3720 */
1226 	rsp_pdu->data = calloc(1, 8192);
1227 	if (!rsp_pdu->data) {
1228 		SPDK_ERRLOG("calloc() failed for data segment\n");
1229 		rsph->status_class = ISCSI_CLASS_TARGET_ERROR;
1230 		rsph->status_detail = ISCSI_LOGIN_STATUS_NO_RESOURCES;
1231 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1232 	}
1233 	rsp_pdu->data_buf_len = 8192;
1234 
1235 	reqh = (struct iscsi_bhs_login_req *)&pdu->bhs;
1236 	rsph->flags |= (reqh->flags & (ISCSI_LOGIN_TRANSIT | ISCSI_LOGIN_CONTINUE |
1237 				       ISCSI_LOGIN_CURRENT_STAGE_MASK));
1238 	if (ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags)) {
1239 		rsph->flags |= (reqh->flags & ISCSI_LOGIN_NEXT_STAGE_MASK);
1240 	}
1241 
1242 	/* We don't need to convert from network byte order. Just store it */
1243 	memcpy(&rsph->isid, reqh->isid, 6);
1244 	rsph->tsih = reqh->tsih;
1245 	rsph->itt = reqh->itt;
1246 	rsp_pdu->cmd_sn = from_be32(&reqh->cmd_sn);
1247 
1248 	if (rsph->tsih) {
1249 		rsph->stat_sn = reqh->exp_stat_sn;
1250 	}
1251 
1252 	SPDK_LOGDUMP(iscsi, "PDU", (uint8_t *)&pdu->bhs, ISCSI_BHS_LEN);
1253 
1254 	SPDK_DEBUGLOG(iscsi,
1255 		      "T=%d, C=%d, CSG=%d, NSG=%d, Min=%d, Max=%d, ITT=%x\n",
1256 		      ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags),
1257 		      ISCSI_BHS_LOGIN_GET_CBIT(rsph->flags),
1258 		      ISCSI_BHS_LOGIN_GET_CSG(rsph->flags),
1259 		      ISCSI_BHS_LOGIN_GET_NSG(rsph->flags),
1260 		      reqh->version_min, reqh->version_max, from_be32(&rsph->itt));
1261 
1262 	if (conn->sess != NULL) {
1263 		SPDK_DEBUGLOG(iscsi,
1264 			      "CmdSN=%u, ExpStatSN=%u, StatSN=%u, ExpCmdSN=%u,"
1265 			      "MaxCmdSN=%u\n", rsp_pdu->cmd_sn,
1266 			      from_be32(&rsph->stat_sn), conn->StatSN,
1267 			      conn->sess->ExpCmdSN,
1268 			      conn->sess->MaxCmdSN);
1269 	} else {
1270 		SPDK_DEBUGLOG(iscsi,
1271 			      "CmdSN=%u, ExpStatSN=%u, StatSN=%u\n",
1272 			      rsp_pdu->cmd_sn, from_be32(&rsph->stat_sn),
1273 			      conn->StatSN);
1274 	}
1275 
1276 	if (ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags) &&
1277 	    ISCSI_BHS_LOGIN_GET_CBIT(rsph->flags)) {
1278 		SPDK_ERRLOG("transit error\n");
1279 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1280 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
1281 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1282 	}
1283 	/* make sure reqh->version_max < ISCSI_VERSION */
1284 	if (reqh->version_min > ISCSI_VERSION) {
1285 		SPDK_ERRLOG("unsupported version min %d/max %d, expecting %d\n", reqh->version_min,
1286 			    reqh->version_max, ISCSI_VERSION);
1287 		/* Unsupported version */
1288 		/* set all reserved flag to zero */
1289 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1290 		rsph->status_detail = ISCSI_LOGIN_UNSUPPORTED_VERSION;
1291 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1292 	}
1293 
1294 	if ((ISCSI_BHS_LOGIN_GET_NSG(rsph->flags) == ISCSI_NSG_RESERVED_CODE) &&
1295 	    ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags)) {
1296 		/* set NSG and other bits to zero */
1297 		rsph->flags &= ~(ISCSI_LOGIN_NEXT_STAGE_MASK | ISCSI_LOGIN_TRANSIT |
1298 				 ISCSI_LOGIN_CURRENT_STAGE_MASK);
1299 		SPDK_ERRLOG("Received reserved NSG code: %d\n", ISCSI_NSG_RESERVED_CODE);
1300 		/* Initiator error */
1301 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1302 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
1303 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1304 	}
1305 
1306 	return 0;
1307 }
1308 
1309 static int
1310 iscsi_op_login_store_incoming_params(struct spdk_iscsi_conn *conn,
1311 				     struct spdk_iscsi_pdu *pdu, struct spdk_iscsi_pdu *rsp_pdu,
1312 				     struct iscsi_param **params)
1313 {
1314 	struct iscsi_bhs_login_req *reqh;
1315 	struct iscsi_bhs_login_rsp *rsph;
1316 	int rc;
1317 
1318 	reqh = (struct iscsi_bhs_login_req *)&pdu->bhs;
1319 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1320 
1321 	rc = iscsi_parse_params(params, pdu->data,
1322 				pdu->data_segment_len, ISCSI_BHS_LOGIN_GET_CBIT(reqh->flags),
1323 				&conn->partial_text_parameter);
1324 	if (rc < 0) {
1325 		SPDK_ERRLOG("iscsi_parse_params() failed\n");
1326 		iscsi_param_free(*params);
1327 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1328 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
1329 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1330 	}
1331 
1332 	return 0;
1333 }
1334 
1335 /*
1336  * This function is used to initialize the port info
1337  * return
1338  * 0: success
1339  * otherwise: error
1340  */
1341 static int
1342 iscsi_op_login_initialize_port(struct spdk_iscsi_conn *conn,
1343 			       struct spdk_iscsi_pdu *rsp_pdu,
1344 			       char *initiator_port_name,
1345 			       uint32_t name_length,
1346 			       struct iscsi_param *params)
1347 {
1348 	const char *val;
1349 	struct iscsi_bhs_login_rsp *rsph;
1350 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1351 
1352 	/* Initiator Name and Port */
1353 	val = iscsi_param_get_val(params, "InitiatorName");
1354 	if (val == NULL) {
1355 		SPDK_ERRLOG("InitiatorName is empty\n");
1356 		/* Missing parameter */
1357 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1358 		rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1359 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1360 	}
1361 	snprintf(conn->initiator_name, sizeof(conn->initiator_name), "%s", val);
1362 	snprintf(initiator_port_name, name_length,
1363 		 "%s,i,0x%12.12" PRIx64, val, iscsi_get_isid(rsph->isid));
1364 	spdk_strlwr(conn->initiator_name);
1365 	spdk_strlwr(initiator_port_name);
1366 	SPDK_DEBUGLOG(iscsi, "Initiator name: %s\n", conn->initiator_name);
1367 	SPDK_DEBUGLOG(iscsi, "Initiator port: %s\n", initiator_port_name);
1368 
1369 	return 0;
1370 }
1371 
1372 /*
1373  * This function is used to judge the session type
1374  * return
1375  * 0: success
1376  * Other value: error
1377  */
1378 static int
1379 iscsi_op_login_session_type(struct spdk_iscsi_conn *conn,
1380 			    struct spdk_iscsi_pdu *rsp_pdu,
1381 			    enum session_type *session_type,
1382 			    struct iscsi_param *params)
1383 {
1384 	const char *session_type_str;
1385 	struct iscsi_bhs_login_rsp *rsph;
1386 
1387 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1388 	session_type_str = iscsi_param_get_val(params, "SessionType");
1389 	if (session_type_str == NULL) {
1390 		if (rsph->tsih != 0) {
1391 			*session_type = SESSION_TYPE_NORMAL;
1392 		} else {
1393 			SPDK_ERRLOG("SessionType is empty\n");
1394 			/* Missing parameter */
1395 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1396 			rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1397 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1398 		}
1399 	} else {
1400 		if (strcasecmp(session_type_str, "Discovery") == 0) {
1401 			*session_type = SESSION_TYPE_DISCOVERY;
1402 		} else if (strcasecmp(session_type_str, "Normal") == 0) {
1403 			*session_type = SESSION_TYPE_NORMAL;
1404 		} else {
1405 			*session_type = SESSION_TYPE_INVALID;
1406 			SPDK_ERRLOG("SessionType is invalid\n");
1407 			/* Missing parameter */
1408 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1409 			rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1410 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1411 		}
1412 	}
1413 	SPDK_DEBUGLOG(iscsi, "Session Type: %s\n", session_type_str);
1414 
1415 	return 0;
1416 }
1417 
1418 /*
1419  * This function is used to check the target info
1420  * return:
1421  * 0: success
1422  * otherwise: error
1423  */
1424 static int
1425 iscsi_op_login_check_target(struct spdk_iscsi_conn *conn,
1426 			    struct spdk_iscsi_pdu *rsp_pdu,
1427 			    const char *target_name,
1428 			    struct spdk_iscsi_tgt_node **target)
1429 {
1430 	struct iscsi_bhs_login_rsp *rsph;
1431 	char buf[MAX_TMPBUF] = {};
1432 
1433 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1434 	*target = iscsi_find_tgt_node(target_name);
1435 	if (*target == NULL) {
1436 		SPDK_WARNLOG("target %s not found\n", target_name);
1437 		/* Not found */
1438 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1439 		rsph->status_detail = ISCSI_LOGIN_TARGET_NOT_FOUND;
1440 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1441 	}
1442 	if (iscsi_tgt_node_is_destructed(*target)) {
1443 		SPDK_ERRLOG("target %s is removed\n", target_name);
1444 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1445 		rsph->status_detail = ISCSI_LOGIN_TARGET_REMOVED;
1446 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1447 	}
1448 	if (iscsi_tgt_node_is_redirected(conn, *target, buf, MAX_TMPBUF)) {
1449 		SPDK_INFOLOG(iscsi, "target %s is redirectd\n", target_name);
1450 		rsp_pdu->data_segment_len = iscsi_append_text("TargetAddress",
1451 					    buf,
1452 					    rsp_pdu->data,
1453 					    rsp_pdu->data_buf_len,
1454 					    rsp_pdu->data_segment_len);
1455 		rsph->status_class = ISCSI_CLASS_REDIRECT;
1456 		rsph->status_detail = ISCSI_LOGIN_TARGET_TEMPORARILY_MOVED;
1457 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1458 	}
1459 	if (!iscsi_tgt_node_access(conn, *target, conn->initiator_name,
1460 				   conn->initiator_addr)) {
1461 		SPDK_ERRLOG("access denied\n");
1462 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1463 		rsph->status_detail = ISCSI_LOGIN_AUTHORIZATION_FAIL;
1464 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1465 	}
1466 
1467 	return 0;
1468 }
1469 
1470 /*
1471  * This function use to check the session
1472  * return:
1473  * 0, success
1474  * otherwise: error
1475  */
1476 static int
1477 iscsi_op_login_check_session(struct spdk_iscsi_conn *conn,
1478 			     struct spdk_iscsi_pdu *rsp_pdu,
1479 			     char *initiator_port_name, int cid)
1480 
1481 {
1482 	int rc = 0;
1483 	struct iscsi_bhs_login_rsp *rsph;
1484 
1485 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1486 	/* check existing session */
1487 	SPDK_DEBUGLOG(iscsi, "isid=%"PRIx64", tsih=%u, cid=%u\n",
1488 		      iscsi_get_isid(rsph->isid), from_be16(&rsph->tsih), cid);
1489 	if (rsph->tsih != 0) {
1490 		/* multiple connections */
1491 		rc = append_iscsi_sess(conn, initiator_port_name,
1492 				       from_be16(&rsph->tsih), cid);
1493 		if (rc != 0) {
1494 			SPDK_ERRLOG("isid=%"PRIx64", tsih=%u, cid=%u:"
1495 				    "spdk_append_iscsi_sess() failed\n",
1496 				    iscsi_get_isid(rsph->isid), from_be16(&rsph->tsih),
1497 				    cid);
1498 			/* Can't include in session */
1499 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1500 			rsph->status_detail = rc;
1501 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1502 		}
1503 	} else if (!g_iscsi.AllowDuplicateIsid) {
1504 		/* new session, drop old sess by the initiator */
1505 		iscsi_drop_conns(conn, initiator_port_name, 0 /* drop old */);
1506 	}
1507 
1508 	return rc;
1509 }
1510 
1511 /*
1512  * This function is used to del the original param and update it with new
1513  * value
1514  * return:
1515  * 0: success
1516  * otherwise: error
1517  */
1518 static int
1519 iscsi_op_login_update_param(struct spdk_iscsi_conn *conn,
1520 			    const char *key, const char *value,
1521 			    const char *list)
1522 {
1523 	int rc = 0;
1524 	struct iscsi_param *new_param, *orig_param;
1525 	int index;
1526 
1527 	orig_param = iscsi_param_find(conn->params, key);
1528 	if (orig_param == NULL) {
1529 		SPDK_ERRLOG("orig_param %s not found\n", key);
1530 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1531 	}
1532 
1533 	index = orig_param->state_index;
1534 	rc = iscsi_param_del(&conn->params, key);
1535 	if (rc < 0) {
1536 		SPDK_ERRLOG("iscsi_param_del(%s) failed\n", key);
1537 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1538 	}
1539 	rc = iscsi_param_add(&conn->params, key, value, list, ISPT_LIST);
1540 	if (rc < 0) {
1541 		SPDK_ERRLOG("iscsi_param_add() failed\n");
1542 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1543 	}
1544 	new_param = iscsi_param_find(conn->params, key);
1545 	if (new_param == NULL) {
1546 		SPDK_ERRLOG("iscsi_param_find() failed\n");
1547 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1548 	}
1549 	new_param->state_index = index;
1550 	return rc;
1551 }
1552 
1553 static int
1554 iscsi_negotiate_chap_param(struct spdk_iscsi_conn *conn)
1555 {
1556 	int rc = 0;
1557 
1558 	if (conn->disable_chap) {
1559 		rc = iscsi_op_login_update_param(conn, "AuthMethod", "None", "None");
1560 	} else if (conn->require_chap) {
1561 		rc = iscsi_op_login_update_param(conn, "AuthMethod", "CHAP", "CHAP");
1562 	}
1563 
1564 	return rc;
1565 }
1566 
1567 /*
1568  * The function which is used to handle the part of session discovery
1569  * return:
1570  * 0, success;
1571  * otherwise: error;
1572  */
1573 static int
1574 iscsi_op_login_session_discovery_chap(struct spdk_iscsi_conn *conn)
1575 {
1576 	return iscsi_negotiate_chap_param(conn);
1577 }
1578 
1579 /*
1580  * This function is used to update the param related with chap
1581  * return:
1582  * 0: success
1583  * otherwise: error
1584  */
1585 static int
1586 iscsi_op_login_negotiate_chap_param(struct spdk_iscsi_conn *conn,
1587 				    struct spdk_iscsi_tgt_node *target)
1588 {
1589 	conn->disable_chap = target->disable_chap;
1590 	conn->require_chap = target->require_chap;
1591 	conn->mutual_chap = target->mutual_chap;
1592 	conn->chap_group = target->chap_group;
1593 
1594 	return iscsi_negotiate_chap_param(conn);
1595 }
1596 
1597 static int
1598 iscsi_op_login_negotiate_digest_param(struct spdk_iscsi_conn *conn,
1599 				      struct spdk_iscsi_tgt_node *target)
1600 {
1601 	int rc;
1602 
1603 	if (target->header_digest) {
1604 		/*
1605 		 * User specified header digests, so update the list of
1606 		 *  HeaderDigest values to remove "None" so that only
1607 		 *  initiators who support CRC32C can connect.
1608 		 */
1609 		rc = iscsi_op_login_update_param(conn, "HeaderDigest", "CRC32C", "CRC32C");
1610 		if (rc < 0) {
1611 			return rc;
1612 		}
1613 	}
1614 
1615 	if (target->data_digest) {
1616 		/*
1617 		 * User specified data digests, so update the list of
1618 		 *  DataDigest values to remove "None" so that only
1619 		 *  initiators who support CRC32C can connect.
1620 		 */
1621 		rc = iscsi_op_login_update_param(conn, "DataDigest", "CRC32C", "CRC32C");
1622 		if (rc < 0) {
1623 			return rc;
1624 		}
1625 	}
1626 
1627 	return 0;
1628 }
1629 
1630 /*
1631  * The function which is used to handle the part of normal login session
1632  * return:
1633  * 0, success;
1634  * SPDK_ISCSI_LOGIN_ERROR_PARAMETER, parameter error;
1635  */
1636 static int
1637 iscsi_op_login_session_normal(struct spdk_iscsi_conn *conn,
1638 			      struct spdk_iscsi_pdu *rsp_pdu,
1639 			      char *initiator_port_name,
1640 			      struct iscsi_param *params,
1641 			      int cid)
1642 {
1643 	struct spdk_iscsi_tgt_node *target = NULL;
1644 	const char *target_name;
1645 	const char *target_short_name;
1646 	struct iscsi_bhs_login_rsp *rsph;
1647 	int rc = 0;
1648 
1649 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1650 	target_name = iscsi_param_get_val(params, "TargetName");
1651 
1652 	if (target_name == NULL) {
1653 		SPDK_ERRLOG("TargetName is empty\n");
1654 		/* Missing parameter */
1655 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1656 		rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1657 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1658 	}
1659 
1660 	memset(conn->target_short_name, 0, MAX_TARGET_NAME);
1661 	target_short_name = strstr(target_name, ":");
1662 	if (target_short_name != NULL) {
1663 		target_short_name++; /* Advance past the ':' */
1664 		if (strlen(target_short_name) >= MAX_TARGET_NAME) {
1665 			SPDK_ERRLOG("Target Short Name (%s) is more than %u characters\n",
1666 				    target_short_name, MAX_TARGET_NAME);
1667 			/* Invalid request */
1668 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1669 			rsph->status_detail = ISCSI_LOGIN_INVALID_LOGIN_REQUEST;
1670 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1671 		}
1672 		snprintf(conn->target_short_name, MAX_TARGET_NAME, "%s",
1673 			 target_short_name);
1674 	}
1675 
1676 	pthread_mutex_lock(&g_iscsi.mutex);
1677 	rc = iscsi_op_login_check_target(conn, rsp_pdu, target_name, &target);
1678 	pthread_mutex_unlock(&g_iscsi.mutex);
1679 
1680 	if (rc < 0) {
1681 		return rc;
1682 	}
1683 
1684 	conn->target = target;
1685 	conn->dev = target->dev;
1686 	conn->target_port = spdk_scsi_dev_find_port_by_id(target->dev,
1687 			    conn->pg_tag);
1688 
1689 	rc = iscsi_op_login_check_session(conn, rsp_pdu,
1690 					  initiator_port_name, cid);
1691 	if (rc < 0) {
1692 		return rc;
1693 	}
1694 
1695 	/* force target flags */
1696 	pthread_mutex_lock(&target->mutex);
1697 	rc = iscsi_op_login_negotiate_chap_param(conn, target);
1698 	pthread_mutex_unlock(&target->mutex);
1699 
1700 	if (rc == 0) {
1701 		rc = iscsi_op_login_negotiate_digest_param(conn, target);
1702 	}
1703 
1704 	if (rc != 0) {
1705 		/* Invalid request */
1706 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1707 		rsph->status_detail = ISCSI_LOGIN_INVALID_LOGIN_REQUEST;
1708 	}
1709 
1710 	return rc;
1711 }
1712 
1713 /*
1714  * This function is used to set the info in the connection data structure
1715  * return
1716  * 0: success
1717  * otherwise: error
1718  */
1719 static int
1720 iscsi_op_login_set_conn_info(struct spdk_iscsi_conn *conn,
1721 			     struct spdk_iscsi_pdu *rsp_pdu,
1722 			     char *initiator_port_name,
1723 			     enum session_type session_type, int cid)
1724 {
1725 	int rc = 0;
1726 	struct spdk_iscsi_tgt_node *target;
1727 	struct iscsi_bhs_login_rsp *rsph;
1728 	struct spdk_scsi_port *initiator_port;
1729 
1730 	target = conn->target;
1731 
1732 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1733 	conn->authenticated = false;
1734 	conn->auth.chap_phase = ISCSI_CHAP_PHASE_WAIT_A;
1735 	conn->cid = cid;
1736 
1737 	if (conn->sess == NULL) {
1738 		/* create initiator port */
1739 		initiator_port = spdk_scsi_port_create(iscsi_get_isid(rsph->isid), 0, initiator_port_name);
1740 		if (initiator_port == NULL) {
1741 			SPDK_ERRLOG("create_port() failed\n");
1742 			rsph->status_class = ISCSI_CLASS_TARGET_ERROR;
1743 			rsph->status_detail = ISCSI_LOGIN_STATUS_NO_RESOURCES;
1744 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1745 		}
1746 
1747 		/* new session */
1748 		rc = create_iscsi_sess(conn, target, session_type);
1749 		if (rc < 0) {
1750 			spdk_scsi_port_free(&initiator_port);
1751 			SPDK_ERRLOG("create_sess() failed\n");
1752 			rsph->status_class = ISCSI_CLASS_TARGET_ERROR;
1753 			rsph->status_detail = ISCSI_LOGIN_STATUS_NO_RESOURCES;
1754 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1755 		}
1756 		/* initialize parameters */
1757 		conn->sess->initiator_port = initiator_port;
1758 		conn->StatSN = from_be32(&rsph->stat_sn);
1759 		conn->sess->isid = iscsi_get_isid(rsph->isid);
1760 
1761 		/* Initiator port TransportID */
1762 		spdk_scsi_port_set_iscsi_transport_id(conn->sess->initiator_port,
1763 						      conn->initiator_name,
1764 						      conn->sess->isid);
1765 
1766 		/* Discovery sessions will not have a target. */
1767 		if (target != NULL) {
1768 			conn->sess->queue_depth = target->queue_depth;
1769 		} else {
1770 			/*
1771 			 * Assume discovery sessions have an effective command
1772 			 *  windows size of 1.
1773 			 */
1774 			conn->sess->queue_depth = 1;
1775 		}
1776 		conn->sess->ExpCmdSN = rsp_pdu->cmd_sn;
1777 		conn->sess->MaxCmdSN = rsp_pdu->cmd_sn + conn->sess->queue_depth - 1;
1778 	}
1779 
1780 	conn->initiator_port = conn->sess->initiator_port;
1781 
1782 	return 0;
1783 }
1784 
1785 /*
1786  * This function is used to set the target info
1787  * return
1788  * 0: success
1789  * otherwise: error
1790  */
1791 static int
1792 iscsi_op_login_set_target_info(struct spdk_iscsi_conn *conn,
1793 			       struct spdk_iscsi_pdu *rsp_pdu,
1794 			       enum session_type session_type)
1795 {
1796 	char buf[MAX_TMPBUF];
1797 	const char *val;
1798 	int rc = 0;
1799 	struct spdk_iscsi_tgt_node *target = conn->target;
1800 
1801 	/* declarative parameters */
1802 	if (target != NULL) {
1803 		pthread_mutex_lock(&target->mutex);
1804 		if (target->alias[0] != '\0') {
1805 			snprintf(buf, sizeof buf, "%s", target->alias);
1806 		} else {
1807 			snprintf(buf, sizeof buf, "%s", "");
1808 		}
1809 		pthread_mutex_unlock(&target->mutex);
1810 		rc = iscsi_param_set(conn->sess->params, "TargetAlias", buf);
1811 		if (rc < 0) {
1812 			SPDK_ERRLOG("iscsi_param_set() failed\n");
1813 			return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1814 		}
1815 	}
1816 	snprintf(buf, sizeof buf, "%s:%s,%d", conn->portal_host, conn->portal_port,
1817 		 conn->pg_tag);
1818 	rc = iscsi_param_set(conn->sess->params, "TargetAddress", buf);
1819 	if (rc < 0) {
1820 		SPDK_ERRLOG("iscsi_param_set() failed\n");
1821 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1822 	}
1823 	snprintf(buf, sizeof buf, "%d", conn->pg_tag);
1824 	rc = iscsi_param_set(conn->sess->params, "TargetPortalGroupTag", buf);
1825 	if (rc < 0) {
1826 		SPDK_ERRLOG("iscsi_param_set() failed\n");
1827 		return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1828 	}
1829 
1830 	/* write in response */
1831 	if (target != NULL) {
1832 		val = iscsi_param_get_val(conn->sess->params, "TargetAlias");
1833 		if (val != NULL && strlen(val) != 0) {
1834 			rsp_pdu->data_segment_len = iscsi_append_param(conn,
1835 						    "TargetAlias",
1836 						    rsp_pdu->data,
1837 						    rsp_pdu->data_buf_len,
1838 						    rsp_pdu->data_segment_len);
1839 		}
1840 		if (session_type == SESSION_TYPE_DISCOVERY) {
1841 			rsp_pdu->data_segment_len = iscsi_append_param(conn,
1842 						    "TargetAddress",
1843 						    rsp_pdu->data,
1844 						    rsp_pdu->data_buf_len,
1845 						    rsp_pdu->data_segment_len);
1846 		}
1847 		rsp_pdu->data_segment_len = iscsi_append_param(conn,
1848 					    "TargetPortalGroupTag",
1849 					    rsp_pdu->data,
1850 					    rsp_pdu->data_buf_len,
1851 					    rsp_pdu->data_segment_len);
1852 	}
1853 
1854 	return rc;
1855 }
1856 
1857 /*
1858  * This function is used to handle the login of iscsi initiator when there is
1859  * no session
1860  * return:
1861  * 0, success;
1862  * SPDK_ISCSI_LOGIN_ERROR_PARAMETER, parameter error;
1863  * SPDK_ISCSI_LOGIN_ERROR_RESPONSE,  used to notify the login fail.
1864  */
1865 static int
1866 iscsi_op_login_phase_none(struct spdk_iscsi_conn *conn,
1867 			  struct spdk_iscsi_pdu *rsp_pdu,
1868 			  struct iscsi_param *params, int cid)
1869 {
1870 	enum session_type session_type;
1871 	char initiator_port_name[MAX_INITIATOR_PORT_NAME];
1872 	struct iscsi_bhs_login_rsp *rsph;
1873 	int rc = 0;
1874 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1875 
1876 	conn->target = NULL;
1877 	conn->dev = NULL;
1878 
1879 	rc = iscsi_op_login_initialize_port(conn, rsp_pdu, initiator_port_name,
1880 					    MAX_INITIATOR_PORT_NAME, params);
1881 	if (rc < 0) {
1882 		return rc;
1883 	}
1884 
1885 	rc = iscsi_op_login_session_type(conn, rsp_pdu, &session_type, params);
1886 	if (rc < 0) {
1887 		return rc;
1888 	}
1889 
1890 	/* Target Name and Port */
1891 	if (session_type == SESSION_TYPE_NORMAL) {
1892 		rc = iscsi_op_login_session_normal(conn, rsp_pdu,
1893 						   initiator_port_name,
1894 						   params, cid);
1895 		if (rc < 0) {
1896 			return rc;
1897 		}
1898 
1899 	} else if (session_type == SESSION_TYPE_DISCOVERY) {
1900 		rsph->tsih = 0;
1901 
1902 		/* force target flags */
1903 		pthread_mutex_lock(&g_iscsi.mutex);
1904 		rc = iscsi_op_login_session_discovery_chap(conn);
1905 		pthread_mutex_unlock(&g_iscsi.mutex);
1906 		if (rc < 0) {
1907 			return rc;
1908 		}
1909 	} else {
1910 		SPDK_ERRLOG("unknown session type\n");
1911 		/* Missing parameter */
1912 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1913 		rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1914 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1915 	}
1916 
1917 	rc = iscsi_op_login_set_conn_info(conn, rsp_pdu, initiator_port_name,
1918 					  session_type, cid);
1919 	if (rc < 0) {
1920 		return rc;
1921 	}
1922 
1923 	/* limit conns on discovery session */
1924 	if (session_type == SESSION_TYPE_DISCOVERY) {
1925 		conn->sess->MaxConnections = 1;
1926 		rc = iscsi_param_set_int(conn->sess->params,
1927 					 "MaxConnections",
1928 					 conn->sess->MaxConnections);
1929 		if (rc < 0) {
1930 			SPDK_ERRLOG("iscsi_param_set_int() failed\n");
1931 			return SPDK_ISCSI_LOGIN_ERROR_PARAMETER;
1932 		}
1933 	}
1934 
1935 	return iscsi_op_login_set_target_info(conn, rsp_pdu, session_type);
1936 }
1937 
1938 /*
1939  * This function is used to set the csg bit case in rsp
1940  * return:
1941  * 0, success
1942  * otherwise: error
1943  */
1944 static int
1945 iscsi_op_login_rsp_handle_csg_bit(struct spdk_iscsi_conn *conn,
1946 				  struct spdk_iscsi_pdu *rsp_pdu,
1947 				  struct iscsi_param *params)
1948 {
1949 	const char *auth_method;
1950 	int rc;
1951 	struct iscsi_bhs_login_rsp *rsph;
1952 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
1953 
1954 	switch (ISCSI_BHS_LOGIN_GET_CSG(rsph->flags)) {
1955 	case ISCSI_SECURITY_NEGOTIATION_PHASE:
1956 		/* SecurityNegotiation */
1957 		auth_method = iscsi_param_get_val(conn->params, "AuthMethod");
1958 		if (auth_method == NULL) {
1959 			SPDK_ERRLOG("AuthMethod is empty\n");
1960 			/* Missing parameter */
1961 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1962 			rsph->status_detail = ISCSI_LOGIN_MISSING_PARMS;
1963 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1964 		}
1965 		if (strcasecmp(auth_method, "None") == 0) {
1966 			conn->authenticated = true;
1967 		} else {
1968 			rc = iscsi_auth_params(conn, params, auth_method,
1969 					       rsp_pdu->data, rsp_pdu->data_buf_len,
1970 					       rsp_pdu->data_segment_len);
1971 			if (rc < 0) {
1972 				SPDK_ERRLOG("iscsi_auth_params() failed\n");
1973 				/* Authentication failure */
1974 				rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1975 				rsph->status_detail = ISCSI_LOGIN_AUTHENT_FAIL;
1976 				return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
1977 			}
1978 			rsp_pdu->data_segment_len = rc;
1979 			if (!conn->authenticated) {
1980 				/* not complete */
1981 				rsph->flags &= ~ISCSI_LOGIN_TRANSIT;
1982 			} else {
1983 				if (conn->auth.chap_phase != ISCSI_CHAP_PHASE_END) {
1984 					SPDK_DEBUGLOG(iscsi, "CHAP phase not complete");
1985 				}
1986 			}
1987 
1988 			SPDK_LOGDUMP(iscsi, "Negotiated Auth Params",
1989 				     rsp_pdu->data, rsp_pdu->data_segment_len);
1990 		}
1991 		break;
1992 
1993 	case ISCSI_OPERATIONAL_NEGOTIATION_PHASE:
1994 		/* LoginOperationalNegotiation */
1995 		if (conn->state == ISCSI_CONN_STATE_INVALID) {
1996 			if (conn->require_chap) {
1997 				/* Authentication failure */
1998 				rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
1999 				rsph->status_detail = ISCSI_LOGIN_AUTHENT_FAIL;
2000 				return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2001 			} else {
2002 				/* AuthMethod=None */
2003 				conn->authenticated = true;
2004 			}
2005 		}
2006 		if (!conn->authenticated) {
2007 			SPDK_ERRLOG("authentication error\n");
2008 			/* Authentication failure */
2009 			rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2010 			rsph->status_detail = ISCSI_LOGIN_AUTHENT_FAIL;
2011 			return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2012 		}
2013 		break;
2014 
2015 	case ISCSI_FULL_FEATURE_PHASE:
2016 		/* FullFeaturePhase */
2017 		SPDK_ERRLOG("XXX Login in FullFeaturePhase\n");
2018 		/* Initiator error */
2019 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2020 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2021 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2022 
2023 	default:
2024 		SPDK_ERRLOG("unknown stage\n");
2025 		/* Initiator error */
2026 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2027 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2028 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2029 	}
2030 
2031 	return 0;
2032 }
2033 
2034 /* This function is used to notify the session info
2035  * return
2036  * 0: success
2037  * otherwise: error
2038  */
2039 static int
2040 iscsi_op_login_notify_session_info(struct spdk_iscsi_conn *conn,
2041 				   struct spdk_iscsi_pdu *rsp_pdu)
2042 {
2043 	struct iscsi_bhs_login_rsp *rsph;
2044 
2045 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
2046 	if (conn->sess->session_type == SESSION_TYPE_NORMAL) {
2047 		/* normal session */
2048 		SPDK_DEBUGLOG(iscsi, "Login from %s (%s) on %s tgt_node%d"
2049 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2050 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2051 			      conn->initiator_name, conn->initiator_addr,
2052 			      conn->target->name, conn->target->num,
2053 			      conn->portal_host, conn->portal_port, conn->pg_tag,
2054 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2055 			      (iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2056 			       ? "on" : "off"),
2057 			      (iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2058 			       ? "on" : "off"));
2059 	} else if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
2060 		/* discovery session */
2061 		SPDK_DEBUGLOG(iscsi, "Login(discovery) from %s (%s) on"
2062 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2063 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2064 			      conn->initiator_name, conn->initiator_addr,
2065 			      conn->portal_host, conn->portal_port, conn->pg_tag,
2066 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2067 			      (iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2068 			       ? "on" : "off"),
2069 			      (iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2070 			       ? "on" : "off"));
2071 	} else {
2072 		SPDK_ERRLOG("unknown session type\n");
2073 		/* Initiator error */
2074 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2075 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2076 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2077 	}
2078 
2079 	return 0;
2080 }
2081 
2082 /*
2083  * This function is to handle the tbit cases
2084  * return
2085  * 0: success
2086  * otherwise error
2087  */
2088 static int
2089 iscsi_op_login_rsp_handle_t_bit(struct spdk_iscsi_conn *conn,
2090 				struct spdk_iscsi_pdu *rsp_pdu)
2091 {
2092 	int rc;
2093 	struct iscsi_bhs_login_rsp *rsph;
2094 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
2095 
2096 	switch (ISCSI_BHS_LOGIN_GET_NSG(rsph->flags)) {
2097 	case ISCSI_SECURITY_NEGOTIATION_PHASE:
2098 		/* SecurityNegotiation */
2099 		conn->login_phase = ISCSI_SECURITY_NEGOTIATION_PHASE;
2100 		break;
2101 
2102 	case ISCSI_OPERATIONAL_NEGOTIATION_PHASE:
2103 		/* LoginOperationalNegotiation */
2104 		conn->login_phase = ISCSI_OPERATIONAL_NEGOTIATION_PHASE;
2105 		break;
2106 
2107 	case ISCSI_FULL_FEATURE_PHASE:
2108 		/* FullFeaturePhase */
2109 		conn->login_phase = ISCSI_FULL_FEATURE_PHASE;
2110 		to_be16(&rsph->tsih, conn->sess->tsih);
2111 
2112 		rc = iscsi_op_login_notify_session_info(conn, rsp_pdu);
2113 		if (rc < 0) {
2114 			return rc;
2115 		}
2116 
2117 		conn->full_feature = 1;
2118 		break;
2119 
2120 	default:
2121 		SPDK_ERRLOG("unknown stage\n");
2122 		/* Initiator error */
2123 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2124 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2125 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2126 	}
2127 
2128 	return 0;
2129 }
2130 
2131 /*
2132  * This function is used to set the values of the internal data structure used
2133  * by spdk_iscsi_op_login function
2134  * return:
2135  * 0, used to notify the a successful login
2136  * SPDK_ISCSI_LOGIN_ERROR_RESPONSE,  used to notify a failure login.
2137  */
2138 static int
2139 iscsi_op_login_rsp_handle(struct spdk_iscsi_conn *conn,
2140 			  struct spdk_iscsi_pdu *rsp_pdu, struct iscsi_param **params)
2141 {
2142 	int rc;
2143 	struct iscsi_bhs_login_rsp *rsph;
2144 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
2145 
2146 	/* negotiate parameters */
2147 	rc = iscsi_negotiate_params(conn, params, rsp_pdu->data,
2148 				    rsp_pdu->data_buf_len,
2149 				    rsp_pdu->data_segment_len);
2150 	if (rc < 0) {
2151 		/*
2152 		 * iscsi_negotiate_params just returns -1 on failure,
2153 		 *  so translate this into meaningful response codes and
2154 		 *  return values.
2155 		 */
2156 		rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
2157 		rsph->status_detail = ISCSI_LOGIN_INITIATOR_ERROR;
2158 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
2159 	}
2160 
2161 	rsp_pdu->data_segment_len = rc;
2162 	SPDK_LOGDUMP(iscsi, "Negotiated Params", rsp_pdu->data, rc);
2163 
2164 	/* handle the CSG bit case */
2165 	rc = iscsi_op_login_rsp_handle_csg_bit(conn, rsp_pdu, *params);
2166 	if (rc < 0) {
2167 		return rc;
2168 	}
2169 
2170 	/* handle the T bit case */
2171 	if (ISCSI_BHS_LOGIN_GET_TBIT(rsph->flags)) {
2172 		rc = iscsi_op_login_rsp_handle_t_bit(conn, rsp_pdu);
2173 	}
2174 
2175 	return rc;
2176 }
2177 
2178 static int
2179 iscsi_pdu_hdr_op_login(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2180 {
2181 	int rc;
2182 	struct iscsi_bhs_login_req *reqh;
2183 	struct spdk_iscsi_pdu *rsp_pdu;
2184 
2185 	if (conn->full_feature && conn->sess != NULL &&
2186 	    conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
2187 		return SPDK_ISCSI_CONNECTION_FATAL;
2188 	}
2189 
2190 	reqh = (struct iscsi_bhs_login_req *)&pdu->bhs;
2191 	pdu->cmd_sn = from_be32(&reqh->cmd_sn);
2192 
2193 	/* During login processing, use the 8KB default FirstBurstLength as
2194 	 *  our maximum data segment length value.
2195 	 */
2196 	if (pdu->data_segment_len > SPDK_ISCSI_FIRST_BURST_LENGTH) {
2197 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
2198 	}
2199 
2200 	rsp_pdu = iscsi_get_pdu(conn);
2201 	if (rsp_pdu == NULL) {
2202 		return SPDK_ISCSI_CONNECTION_FATAL;
2203 	}
2204 	rc = iscsi_op_login_rsp_init(conn, pdu, rsp_pdu);
2205 	if (rc < 0) {
2206 		iscsi_op_login_response(conn, rsp_pdu, NULL, iscsi_conn_login_pdu_err_complete);
2207 		return 0;
2208 	}
2209 
2210 	conn->login_rsp_pdu = rsp_pdu;
2211 	return 0;
2212 }
2213 
2214 static int
2215 iscsi_pdu_payload_op_login(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2216 {
2217 	int rc;
2218 	struct iscsi_bhs_login_req *reqh;
2219 	struct spdk_iscsi_pdu *rsp_pdu;
2220 	struct iscsi_param *params = NULL;
2221 	int cid;
2222 
2223 	if (conn->login_rsp_pdu == NULL) {
2224 		return 0;
2225 	}
2226 
2227 	rsp_pdu = conn->login_rsp_pdu;
2228 
2229 	reqh = (struct iscsi_bhs_login_req *)&pdu->bhs;
2230 	cid = from_be16(&reqh->cid);
2231 
2232 	rc = iscsi_op_login_store_incoming_params(conn, pdu, rsp_pdu, &params);
2233 	if (rc < 0) {
2234 		iscsi_op_login_response(conn, rsp_pdu, NULL, iscsi_conn_login_pdu_err_complete);
2235 		return 0;
2236 	}
2237 
2238 	if (conn->state == ISCSI_CONN_STATE_INVALID) {
2239 		rc = iscsi_op_login_phase_none(conn, rsp_pdu, params, cid);
2240 		if (rc == SPDK_ISCSI_LOGIN_ERROR_RESPONSE || rc == SPDK_ISCSI_LOGIN_ERROR_PARAMETER) {
2241 			iscsi_op_login_response(conn, rsp_pdu, params, iscsi_conn_login_pdu_err_complete);
2242 			return 0;
2243 		}
2244 	}
2245 
2246 	rc = iscsi_op_login_rsp_handle(conn, rsp_pdu, &params);
2247 	if (rc == SPDK_ISCSI_LOGIN_ERROR_RESPONSE) {
2248 		iscsi_op_login_response(conn, rsp_pdu, params, iscsi_conn_login_pdu_err_complete);
2249 		return 0;
2250 	}
2251 
2252 	iscsi_op_login_response(conn, rsp_pdu, params, iscsi_conn_login_pdu_success_complete);
2253 	return 0;
2254 }
2255 
2256 static int
2257 iscsi_pdu_hdr_op_text(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2258 {
2259 	uint32_t task_tag;
2260 	uint32_t ExpStatSN;
2261 	int F_bit, C_bit;
2262 	struct iscsi_bhs_text_req *reqh;
2263 
2264 	if (pdu->data_segment_len > iscsi_get_max_immediate_data_size()) {
2265 		SPDK_ERRLOG("data segment len(=%zu) > immediate data len(=%"PRIu32")\n",
2266 			    pdu->data_segment_len, iscsi_get_max_immediate_data_size());
2267 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
2268 	}
2269 
2270 	reqh = (struct iscsi_bhs_text_req *)&pdu->bhs;
2271 
2272 	F_bit = !!(reqh->flags & ISCSI_FLAG_FINAL);
2273 	C_bit = !!(reqh->flags & ISCSI_TEXT_CONTINUE);
2274 	task_tag = from_be32(&reqh->itt);
2275 	ExpStatSN = from_be32(&reqh->exp_stat_sn);
2276 
2277 	SPDK_DEBUGLOG(iscsi, "I=%d, F=%d, C=%d, ITT=%x, TTT=%x\n",
2278 		      reqh->immediate, F_bit, C_bit, task_tag, from_be32(&reqh->ttt));
2279 
2280 	SPDK_DEBUGLOG(iscsi,
2281 		      "CmdSN=%u, ExpStatSN=%u, StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
2282 		      pdu->cmd_sn, ExpStatSN, conn->StatSN, conn->sess->ExpCmdSN,
2283 		      conn->sess->MaxCmdSN);
2284 
2285 	if (ExpStatSN != conn->StatSN) {
2286 #if 0
2287 		SPDK_ERRLOG("StatSN(%u) error\n", ExpStatSN);
2288 		return -1;
2289 #else
2290 		/* StarPort have a bug */
2291 		SPDK_DEBUGLOG(iscsi, "StatSN(%u) rewound\n", ExpStatSN);
2292 		conn->StatSN = ExpStatSN;
2293 #endif
2294 	}
2295 
2296 	if (F_bit && C_bit) {
2297 		SPDK_ERRLOG("final and continue\n");
2298 		return -1;
2299 	}
2300 
2301 	/*
2302 	 * If this is the first text op in a sequence, save the ITT so we can
2303 	 * compare it against the ITT for subsequent ops in the same sequence.
2304 	 * If a subsequent text op in same sequence has a different ITT, reject
2305 	 * that PDU.
2306 	 */
2307 	if (conn->sess->current_text_itt == 0xffffffffU) {
2308 		conn->sess->current_text_itt = task_tag;
2309 	} else if (conn->sess->current_text_itt != task_tag) {
2310 		SPDK_ERRLOG("The correct itt is %u, and the current itt is %u...\n",
2311 			    conn->sess->current_text_itt, task_tag);
2312 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
2313 	}
2314 
2315 	return 0;
2316 }
2317 
2318 static void
2319 iscsi_conn_text_pdu_complete(void *arg)
2320 {
2321 	struct spdk_iscsi_conn *conn = arg;
2322 
2323 	iscsi_conn_params_update(conn);
2324 }
2325 
2326 static int
2327 iscsi_pdu_payload_op_text(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2328 {
2329 	struct iscsi_param *params = NULL;
2330 	struct spdk_iscsi_pdu *rsp_pdu;
2331 	uint8_t *data;
2332 	uint64_t lun;
2333 	uint32_t task_tag;
2334 	const char *val;
2335 	int F_bit, C_bit;
2336 	int data_len;
2337 	int alloc_len;
2338 	int rc;
2339 	struct iscsi_bhs_text_req *reqh;
2340 	struct iscsi_bhs_text_resp *rsph;
2341 
2342 	data_len = 0;
2343 	alloc_len = conn->MaxRecvDataSegmentLength;
2344 
2345 	reqh = (struct iscsi_bhs_text_req *)&pdu->bhs;
2346 
2347 	F_bit = !!(reqh->flags & ISCSI_FLAG_FINAL);
2348 	C_bit = !!(reqh->flags & ISCSI_TEXT_CONTINUE);
2349 	lun = from_be64(&reqh->lun);
2350 	task_tag = from_be32(&reqh->itt);
2351 
2352 	/* store incoming parameters */
2353 	rc = iscsi_parse_params(&params, pdu->data, pdu->data_segment_len,
2354 				C_bit, &conn->partial_text_parameter);
2355 	if (rc < 0) {
2356 		SPDK_ERRLOG("iscsi_parse_params() failed\n");
2357 		iscsi_param_free(params);
2358 		return -1;
2359 	}
2360 
2361 	data = calloc(1, alloc_len);
2362 	if (!data) {
2363 		SPDK_ERRLOG("calloc() failed for data segment\n");
2364 		iscsi_param_free(params);
2365 		return -ENOMEM;
2366 	}
2367 
2368 	/* negotiate parameters */
2369 	data_len = iscsi_negotiate_params(conn, &params,
2370 					  data, alloc_len, data_len);
2371 	if (data_len < 0) {
2372 		SPDK_ERRLOG("iscsi_negotiate_params() failed\n");
2373 		iscsi_param_free(params);
2374 		free(data);
2375 		return -1;
2376 	}
2377 
2378 	/* sendtargets is special case */
2379 	val = iscsi_param_get_val(params, "SendTargets");
2380 	if (val != NULL) {
2381 		if (iscsi_param_eq_val(conn->sess->params,
2382 				       "SessionType", "Discovery")) {
2383 			if (strcasecmp(val, "") == 0) {
2384 				val = "ALL";
2385 			}
2386 
2387 			data_len = iscsi_send_tgts(conn,
2388 						   conn->initiator_name,
2389 						   val, data, alloc_len,
2390 						   data_len);
2391 		} else {
2392 			if (strcasecmp(val, "") == 0) {
2393 				val = conn->target->name;
2394 			}
2395 
2396 			if (strcasecmp(val, "ALL") == 0) {
2397 				/* not in discovery session */
2398 				data_len = iscsi_append_text("SendTargets", "Reject",
2399 							     data, alloc_len, data_len);
2400 			} else {
2401 				data_len = iscsi_send_tgts(conn,
2402 							   conn->initiator_name,
2403 							   val, data, alloc_len,
2404 							   data_len);
2405 			}
2406 		}
2407 	} else {
2408 		if (iscsi_param_eq_val(conn->sess->params, "SessionType", "Discovery")) {
2409 			iscsi_param_free(params);
2410 			free(data);
2411 			return SPDK_ISCSI_CONNECTION_FATAL;
2412 		}
2413 	}
2414 
2415 	iscsi_param_free(params);
2416 	SPDK_LOGDUMP(iscsi, "Negotiated Params", data, data_len);
2417 
2418 	/* response PDU */
2419 	rsp_pdu = iscsi_get_pdu(conn);
2420 	if (rsp_pdu == NULL) {
2421 		free(data);
2422 		return SPDK_ISCSI_CONNECTION_FATAL;
2423 	}
2424 	rsph = (struct iscsi_bhs_text_resp *)&rsp_pdu->bhs;
2425 
2426 	rsp_pdu->data = data;
2427 	rsph->opcode = ISCSI_OP_TEXT_RSP;
2428 
2429 	if (F_bit) {
2430 		rsph->flags |= ISCSI_FLAG_FINAL;
2431 	}
2432 
2433 	if (C_bit) {
2434 		rsph->flags |= ISCSI_TEXT_CONTINUE;
2435 	}
2436 
2437 	DSET24(rsph->data_segment_len, data_len);
2438 	to_be64(&rsph->lun, lun);
2439 	to_be32(&rsph->itt, task_tag);
2440 
2441 	if (F_bit) {
2442 		rsph->ttt = 0xffffffffU;
2443 		conn->sess->current_text_itt = 0xffffffffU;
2444 	} else {
2445 		to_be32(&rsph->ttt, 1 + conn->id);
2446 	}
2447 
2448 	to_be32(&rsph->stat_sn, conn->StatSN);
2449 	conn->StatSN++;
2450 
2451 	if (reqh->immediate == 0) {
2452 		conn->sess->MaxCmdSN++;
2453 	}
2454 
2455 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
2456 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
2457 
2458 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_text_pdu_complete, conn);
2459 	return 0;
2460 }
2461 
2462 static void iscsi_conn_logout_pdu_complete(void *arg)
2463 {
2464 	struct spdk_iscsi_conn *conn = arg;
2465 
2466 	if (conn->sess == NULL) {
2467 		/*
2468 		 * login failed but initiator still sent a logout rather than
2469 		 *  just closing the TCP connection.
2470 		 */
2471 		SPDK_DEBUGLOG(iscsi, "Logout(login failed) from %s (%s) on"
2472 			      " (%s:%s,%d)\n",
2473 			      conn->initiator_name, conn->initiator_addr,
2474 			      conn->portal_host, conn->portal_port, conn->pg_tag);
2475 	} else if (iscsi_param_eq_val(conn->sess->params, "SessionType", "Normal")) {
2476 		SPDK_DEBUGLOG(iscsi, "Logout from %s (%s) on %s tgt_node%d"
2477 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2478 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2479 			      conn->initiator_name, conn->initiator_addr,
2480 			      conn->target->name, conn->target->num,
2481 			      conn->portal_host, conn->portal_port, conn->pg_tag,
2482 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2483 			      (iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2484 			       ? "on" : "off"),
2485 			      (iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2486 			       ? "on" : "off"));
2487 	} else {
2488 		/* discovery session */
2489 		SPDK_DEBUGLOG(iscsi, "Logout(discovery) from %s (%s) on"
2490 			      " (%s:%s,%d), ISID=%"PRIx64", TSIH=%u,"
2491 			      " CID=%u, HeaderDigest=%s, DataDigest=%s\n",
2492 			      conn->initiator_name, conn->initiator_addr,
2493 			      conn->portal_host, conn->portal_port, conn->pg_tag,
2494 			      conn->sess->isid, conn->sess->tsih, conn->cid,
2495 			      (iscsi_param_eq_val(conn->params, "HeaderDigest", "CRC32C")
2496 			       ? "on" : "off"),
2497 			      (iscsi_param_eq_val(conn->params, "DataDigest", "CRC32C")
2498 			       ? "on" : "off"));
2499 	}
2500 }
2501 
2502 static int
2503 iscsi_pdu_hdr_op_logout(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
2504 {
2505 	struct spdk_iscsi_pdu *rsp_pdu;
2506 	uint32_t task_tag;
2507 	uint32_t ExpStatSN;
2508 	int response;
2509 	struct iscsi_bhs_logout_req *reqh;
2510 	struct iscsi_bhs_logout_resp *rsph;
2511 	uint16_t cid;
2512 
2513 	reqh = (struct iscsi_bhs_logout_req *)&pdu->bhs;
2514 
2515 	cid = from_be16(&reqh->cid);
2516 	task_tag = from_be32(&reqh->itt);
2517 	ExpStatSN = from_be32(&reqh->exp_stat_sn);
2518 
2519 	SPDK_DEBUGLOG(iscsi, "reason=%d, ITT=%x, cid=%d\n",
2520 		      reqh->reason, task_tag, cid);
2521 
2522 	if (conn->sess != NULL) {
2523 		if (conn->sess->session_type == SESSION_TYPE_DISCOVERY &&
2524 		    reqh->reason != ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
2525 			SPDK_ERRLOG("Target can accept logout only with reason \"close the session\" "
2526 				    "on discovery session. %d is not acceptable reason.\n",
2527 				    reqh->reason);
2528 			return SPDK_ISCSI_CONNECTION_FATAL;
2529 		}
2530 
2531 		SPDK_DEBUGLOG(iscsi,
2532 			      "CmdSN=%u, ExpStatSN=%u, StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
2533 			      pdu->cmd_sn, ExpStatSN, conn->StatSN,
2534 			      conn->sess->ExpCmdSN, conn->sess->MaxCmdSN);
2535 
2536 		if (pdu->cmd_sn != conn->sess->ExpCmdSN) {
2537 			SPDK_DEBUGLOG(iscsi, "CmdSN(%u) might have dropped\n", pdu->cmd_sn);
2538 			/* ignore error */
2539 		}
2540 	} else {
2541 		SPDK_DEBUGLOG(iscsi, "CmdSN=%u, ExpStatSN=%u, StatSN=%u\n",
2542 			      pdu->cmd_sn, ExpStatSN, conn->StatSN);
2543 	}
2544 
2545 	if (ExpStatSN != conn->StatSN) {
2546 		SPDK_DEBUGLOG(iscsi, "StatSN(%u/%u) might have dropped\n",
2547 			      ExpStatSN, conn->StatSN);
2548 		/* ignore error */
2549 	}
2550 
2551 	if (conn->id == cid) {
2552 		/* connection or session closed successfully */
2553 		response = 0;
2554 		iscsi_conn_logout(conn);
2555 	} else {
2556 		response = 1;
2557 	}
2558 
2559 	/* response PDU */
2560 	rsp_pdu = iscsi_get_pdu(conn);
2561 	if (rsp_pdu == NULL) {
2562 		return SPDK_ISCSI_CONNECTION_FATAL;
2563 	}
2564 	rsph = (struct iscsi_bhs_logout_resp *)&rsp_pdu->bhs;
2565 	rsp_pdu->data = NULL;
2566 	rsph->opcode = ISCSI_OP_LOGOUT_RSP;
2567 	rsph->flags |= 0x80; /* bit 0 must be 1 */
2568 	rsph->response = response;
2569 	DSET24(rsph->data_segment_len, 0);
2570 	to_be32(&rsph->itt, task_tag);
2571 
2572 	if (conn->sess != NULL) {
2573 		to_be32(&rsph->stat_sn, conn->StatSN);
2574 		conn->StatSN++;
2575 
2576 		if (conn->sess->connections == 1) {
2577 			conn->sess->MaxCmdSN++;
2578 		}
2579 
2580 		to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
2581 		to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
2582 	} else {
2583 		to_be32(&rsph->stat_sn, conn->StatSN);
2584 		conn->StatSN++;
2585 		to_be32(&rsph->exp_cmd_sn, pdu->cmd_sn);
2586 		to_be32(&rsph->max_cmd_sn, pdu->cmd_sn);
2587 	}
2588 
2589 	rsph->time_2_wait = 0;
2590 	rsph->time_2_retain = 0;
2591 
2592 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_logout_pdu_complete, conn);
2593 
2594 	return 0;
2595 }
2596 
2597 static int
2598 iscsi_send_r2t(struct spdk_iscsi_conn *conn,
2599 	       struct spdk_iscsi_task *task, int offset,
2600 	       int len, uint32_t transfer_tag, uint32_t *R2TSN)
2601 {
2602 	struct spdk_iscsi_pdu *rsp_pdu;
2603 	struct iscsi_bhs_r2t *rsph;
2604 	uint64_t fmt_lun;
2605 
2606 	/* R2T PDU */
2607 	rsp_pdu = iscsi_get_pdu(conn);
2608 	if (rsp_pdu == NULL) {
2609 		return SPDK_ISCSI_CONNECTION_FATAL;
2610 	}
2611 	rsph = (struct iscsi_bhs_r2t *)&rsp_pdu->bhs;
2612 	rsp_pdu->data = NULL;
2613 	rsph->opcode = ISCSI_OP_R2T;
2614 	rsph->flags |= 0x80; /* bit 0 is default to 1 */
2615 	fmt_lun = spdk_scsi_lun_id_int_to_fmt(task->lun_id);
2616 	to_be64(&rsph->lun, fmt_lun);
2617 	to_be32(&rsph->itt, task->tag);
2618 	to_be32(&rsph->ttt, transfer_tag);
2619 
2620 	to_be32(&rsph->stat_sn, conn->StatSN);
2621 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
2622 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
2623 
2624 	to_be32(&rsph->r2t_sn, *R2TSN);
2625 	*R2TSN += 1;
2626 
2627 	task->r2t_datasn = 0; /* next expected datasn to ack */
2628 
2629 	to_be32(&rsph->buffer_offset, (uint32_t)offset);
2630 	to_be32(&rsph->desired_xfer_len, (uint32_t)len);
2631 	task->desired_data_transfer_length = (size_t)len;
2632 
2633 	/* we need to hold onto this task/cmd because until the PDU has been
2634 	 * written out */
2635 	rsp_pdu->task = task;
2636 	task->scsi.ref++;
2637 
2638 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_pdu_generic_complete, NULL);
2639 
2640 	return 0;
2641 }
2642 
2643 /* This function is used to remove the r2t pdu from snack_pdu_list by < task, r2t_sn> info */
2644 static struct spdk_iscsi_pdu *
2645 iscsi_remove_r2t_pdu_from_snack_list(struct spdk_iscsi_conn *conn,
2646 				     struct spdk_iscsi_task *task,
2647 				     uint32_t r2t_sn)
2648 {
2649 	struct spdk_iscsi_pdu *pdu;
2650 	struct iscsi_bhs_r2t *r2t_header;
2651 
2652 	TAILQ_FOREACH(pdu, &conn->snack_pdu_list, tailq) {
2653 		if (pdu->bhs.opcode == ISCSI_OP_R2T) {
2654 			r2t_header = (struct iscsi_bhs_r2t *)&pdu->bhs;
2655 			if (pdu->task == task &&
2656 			    from_be32(&r2t_header->r2t_sn) == r2t_sn) {
2657 				TAILQ_REMOVE(&conn->snack_pdu_list, pdu, tailq);
2658 				return pdu;
2659 			}
2660 		}
2661 	}
2662 
2663 	return NULL;
2664 }
2665 
2666 /* This function is used re-send the r2t packet */
2667 static int
2668 iscsi_send_r2t_recovery(struct spdk_iscsi_conn *conn,
2669 			struct spdk_iscsi_task *task, uint32_t r2t_sn,
2670 			bool send_new_r2tsn)
2671 {
2672 	struct spdk_iscsi_pdu *pdu;
2673 	struct iscsi_bhs_r2t *rsph;
2674 	uint32_t transfer_len;
2675 	uint32_t len;
2676 	int rc;
2677 
2678 	/* remove the r2t pdu from the snack_list */
2679 	pdu = iscsi_remove_r2t_pdu_from_snack_list(conn, task, r2t_sn);
2680 	if (!pdu) {
2681 		SPDK_DEBUGLOG(iscsi, "No pdu is found\n");
2682 		return -1;
2683 	}
2684 
2685 	/* flag
2686 	 * false: only need to re-send the old r2t with changing statsn
2687 	 * true: we send a r2t with new r2tsn
2688 	 */
2689 	if (!send_new_r2tsn) {
2690 		to_be32(&pdu->bhs.stat_sn, conn->StatSN);
2691 		iscsi_conn_write_pdu(conn, pdu, iscsi_conn_pdu_generic_complete, NULL);
2692 	} else {
2693 		rsph = (struct iscsi_bhs_r2t *)&pdu->bhs;
2694 		transfer_len = from_be32(&rsph->desired_xfer_len);
2695 
2696 		/* still need to increase the acked r2tsn */
2697 		task->acked_r2tsn++;
2698 		len = spdk_min(conn->sess->MaxBurstLength,
2699 			       (transfer_len - task->next_expected_r2t_offset));
2700 
2701 		/* remove the old_r2t_pdu */
2702 		iscsi_conn_free_pdu(conn, pdu);
2703 
2704 		/* re-send a new r2t pdu */
2705 		rc = iscsi_send_r2t(conn, task, task->next_expected_r2t_offset,
2706 				    len, task->ttt, &task->R2TSN);
2707 		if (rc < 0) {
2708 			return SPDK_ISCSI_CONNECTION_FATAL;
2709 		}
2710 	}
2711 
2712 	return 0;
2713 }
2714 
2715 static int
2716 add_transfer_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
2717 {
2718 	uint32_t transfer_len;
2719 	size_t max_burst_len;
2720 	size_t segment_len;
2721 	size_t data_len;
2722 	int len;
2723 	int rc;
2724 	int data_out_req;
2725 
2726 	transfer_len = task->scsi.transfer_len;
2727 	data_len = iscsi_task_get_pdu(task)->data_segment_len;
2728 	max_burst_len = conn->sess->MaxBurstLength;
2729 	segment_len = SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH;
2730 	data_out_req = 1 + (transfer_len - data_len - 1) / segment_len;
2731 	task->data_out_cnt = data_out_req;
2732 
2733 	/*
2734 	 * If we already have too many tasks using R2T, then queue this task
2735 	 *  and start sending R2T for it after some of the tasks using R2T/data
2736 	 *  out buffers complete.
2737 	 */
2738 	if (conn->pending_r2t >= g_iscsi.MaxR2TPerConnection) {
2739 		TAILQ_INSERT_TAIL(&conn->queued_r2t_tasks, task, link);
2740 		return 0;
2741 	}
2742 
2743 	conn->data_out_cnt += data_out_req;
2744 	conn->pending_r2t++;
2745 
2746 	task->next_expected_r2t_offset = data_len;
2747 	task->current_r2t_length = 0;
2748 	task->R2TSN = 0;
2749 	/* According to RFC3720 10.8.5, 0xffffffff is
2750 	 * reserved for TTT in R2T.
2751 	 */
2752 	if (++conn->ttt == 0xffffffffu) {
2753 		conn->ttt = 0;
2754 	}
2755 	task->ttt = conn->ttt;
2756 
2757 	while (data_len != transfer_len) {
2758 		len = spdk_min(max_burst_len, (transfer_len - data_len));
2759 		rc = iscsi_send_r2t(conn, task, data_len, len,
2760 				    task->ttt, &task->R2TSN);
2761 		if (rc < 0) {
2762 			SPDK_ERRLOG("iscsi_send_r2t() failed\n");
2763 			return rc;
2764 		}
2765 		data_len += len;
2766 		task->next_r2t_offset = data_len;
2767 		task->outstanding_r2t++;
2768 		if (conn->sess->MaxOutstandingR2T == task->outstanding_r2t) {
2769 			break;
2770 		}
2771 	}
2772 
2773 	TAILQ_INSERT_TAIL(&conn->active_r2t_tasks, task, link);
2774 	task->is_r2t_active = true;
2775 	return 0;
2776 }
2777 
2778 /* If there are additional large writes queued for R2Ts, start them now.
2779  *  This is called when a large write is just completed or when multiple LUNs
2780  *  are attached and large write tasks for the specific LUN are cleared.
2781  */
2782 static void
2783 start_queued_transfer_tasks(struct spdk_iscsi_conn *conn)
2784 {
2785 	struct spdk_iscsi_task *task, *tmp;
2786 
2787 	TAILQ_FOREACH_SAFE(task, &conn->queued_r2t_tasks, link, tmp) {
2788 		if (conn->pending_r2t < g_iscsi.MaxR2TPerConnection) {
2789 			TAILQ_REMOVE(&conn->queued_r2t_tasks, task, link);
2790 			add_transfer_task(conn, task);
2791 		} else {
2792 			break;
2793 		}
2794 	}
2795 }
2796 
2797 bool
2798 iscsi_del_transfer_task(struct spdk_iscsi_conn *conn, uint32_t task_tag)
2799 {
2800 	struct spdk_iscsi_task *task, *tmp;
2801 
2802 	TAILQ_FOREACH_SAFE(task, &conn->active_r2t_tasks, link, tmp) {
2803 		if (task->tag == task_tag) {
2804 			assert(conn->data_out_cnt >= task->data_out_cnt);
2805 			conn->data_out_cnt -= task->data_out_cnt;
2806 
2807 			assert(conn->pending_r2t > 0);
2808 			conn->pending_r2t--;
2809 
2810 			assert(task->is_r2t_active == true);
2811 			TAILQ_REMOVE(&conn->active_r2t_tasks, task, link);
2812 			task->is_r2t_active = false;
2813 			iscsi_task_put(task);
2814 
2815 			start_queued_transfer_tasks(conn);
2816 			return true;
2817 		}
2818 	}
2819 	return false;
2820 }
2821 
2822 void iscsi_clear_all_transfer_task(struct spdk_iscsi_conn *conn,
2823 				   struct spdk_scsi_lun *lun,
2824 				   struct spdk_iscsi_pdu *pdu)
2825 {
2826 	struct spdk_iscsi_task *task, *task_tmp;
2827 	struct spdk_iscsi_pdu *pdu_tmp;
2828 
2829 	TAILQ_FOREACH_SAFE(task, &conn->active_r2t_tasks, link, task_tmp) {
2830 		pdu_tmp = iscsi_task_get_pdu(task);
2831 		if ((lun == NULL || lun == task->scsi.lun) &&
2832 		    (pdu == NULL || spdk_sn32_lt(pdu_tmp->cmd_sn, pdu->cmd_sn))) {
2833 			task->outstanding_r2t = 0;
2834 			task->next_r2t_offset = 0;
2835 			task->next_expected_r2t_offset = 0;
2836 			assert(conn->data_out_cnt >= task->data_out_cnt);
2837 			conn->data_out_cnt -= task->data_out_cnt;
2838 			assert(conn->pending_r2t > 0);
2839 			conn->pending_r2t--;
2840 
2841 			TAILQ_REMOVE(&conn->active_r2t_tasks, task, link);
2842 			task->is_r2t_active = false;
2843 			if (lun != NULL && spdk_scsi_lun_is_removing(lun)) {
2844 				spdk_scsi_task_process_null_lun(&task->scsi);
2845 				iscsi_task_response(conn, task);
2846 			}
2847 			iscsi_task_put(task);
2848 		}
2849 	}
2850 
2851 	TAILQ_FOREACH_SAFE(task, &conn->queued_r2t_tasks, link, task_tmp) {
2852 		pdu_tmp = iscsi_task_get_pdu(task);
2853 		if ((lun == NULL || lun == task->scsi.lun) &&
2854 		    (pdu == NULL || spdk_sn32_lt(pdu_tmp->cmd_sn, pdu->cmd_sn))) {
2855 			TAILQ_REMOVE(&conn->queued_r2t_tasks, task, link);
2856 			task->is_r2t_active = false;
2857 			if (lun != NULL && spdk_scsi_lun_is_removing(lun)) {
2858 				spdk_scsi_task_process_null_lun(&task->scsi);
2859 				iscsi_task_response(conn, task);
2860 			}
2861 			iscsi_task_put(task);
2862 		}
2863 	}
2864 
2865 	start_queued_transfer_tasks(conn);
2866 }
2867 
2868 static struct spdk_iscsi_task *
2869 get_transfer_task(struct spdk_iscsi_conn *conn, uint32_t transfer_tag)
2870 {
2871 	struct spdk_iscsi_task *task;
2872 
2873 	TAILQ_FOREACH(task, &conn->active_r2t_tasks, link) {
2874 		if (task->ttt == transfer_tag) {
2875 			return task;
2876 		}
2877 	}
2878 
2879 	return NULL;
2880 }
2881 
2882 static void
2883 iscsi_conn_datain_pdu_complete(void *arg)
2884 {
2885 	struct spdk_iscsi_conn *conn = arg;
2886 
2887 	iscsi_conn_handle_queued_datain_tasks(conn);
2888 }
2889 
2890 static int
2891 iscsi_send_datain(struct spdk_iscsi_conn *conn,
2892 		  struct spdk_iscsi_task *task, int datain_flag,
2893 		  int residual_len, int offset, int DataSN, int len)
2894 {
2895 	struct spdk_iscsi_pdu *rsp_pdu;
2896 	struct iscsi_bhs_data_in *rsph;
2897 	uint32_t task_tag;
2898 	uint32_t transfer_tag;
2899 	int F_bit, U_bit, O_bit, S_bit;
2900 	struct spdk_iscsi_task *primary;
2901 	struct spdk_scsi_lun *lun_dev;
2902 
2903 	primary = iscsi_task_get_primary(task);
2904 
2905 	/* DATA PDU */
2906 	rsp_pdu = iscsi_get_pdu(conn);
2907 	rsph = (struct iscsi_bhs_data_in *)&rsp_pdu->bhs;
2908 	rsp_pdu->data = task->scsi.iovs[0].iov_base + offset;
2909 	rsp_pdu->data_buf_len = task->scsi.iovs[0].iov_len - offset;
2910 	rsp_pdu->data_from_mempool = true;
2911 
2912 	task_tag = task->tag;
2913 	transfer_tag = 0xffffffffU;
2914 
2915 	F_bit = datain_flag & ISCSI_FLAG_FINAL;
2916 	O_bit = datain_flag & ISCSI_DATAIN_OVERFLOW;
2917 	U_bit = datain_flag & ISCSI_DATAIN_UNDERFLOW;
2918 	S_bit = datain_flag & ISCSI_DATAIN_STATUS;
2919 
2920 	/*
2921 	 * we need to hold onto this task/cmd because until the
2922 	 * PDU has been written out
2923 	 */
2924 	rsp_pdu->task = task;
2925 	task->scsi.ref++;
2926 
2927 	rsph->opcode = ISCSI_OP_SCSI_DATAIN;
2928 
2929 	if (F_bit) {
2930 		rsph->flags |= ISCSI_FLAG_FINAL;
2931 	}
2932 
2933 	/* we leave the A_bit clear */
2934 
2935 	if (F_bit && S_bit)  {
2936 		if (O_bit) {
2937 			rsph->flags |= ISCSI_DATAIN_OVERFLOW;
2938 		}
2939 
2940 		if (U_bit) {
2941 			rsph->flags |= ISCSI_DATAIN_UNDERFLOW;
2942 		}
2943 	}
2944 
2945 	if (S_bit) {
2946 		rsph->flags |= ISCSI_DATAIN_STATUS;
2947 		rsph->status = task->scsi.status;
2948 	}
2949 
2950 	DSET24(rsph->data_segment_len, len);
2951 
2952 	to_be32(&rsph->itt, task_tag);
2953 	to_be32(&rsph->ttt, transfer_tag);
2954 
2955 	if (S_bit) {
2956 		to_be32(&rsph->stat_sn, conn->StatSN);
2957 		conn->StatSN++;
2958 	}
2959 
2960 	if (F_bit && S_bit && !iscsi_task_is_immediate(primary)) {
2961 		conn->sess->MaxCmdSN++;
2962 	}
2963 
2964 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
2965 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
2966 
2967 	to_be32(&rsph->data_sn, DataSN);
2968 
2969 	if (conn->sess->ErrorRecoveryLevel >= 1) {
2970 		primary->datain_datasn = DataSN;
2971 	}
2972 	DataSN++;
2973 
2974 	if (task->parent) {
2975 		offset += primary->scsi.data_transferred;
2976 	}
2977 	to_be32(&rsph->buffer_offset, (uint32_t)offset);
2978 	task->scsi.offset = offset;
2979 
2980 	if (F_bit && S_bit) {
2981 		to_be32(&rsph->res_cnt, residual_len);
2982 	}
2983 
2984 	lun_dev = spdk_scsi_dev_get_lun(conn->dev, task->lun_id);
2985 	if (spdk_likely(lun_dev != NULL)) {
2986 		if (spdk_unlikely(spdk_scsi_lun_get_dif_ctx(lun_dev, &task->scsi,
2987 				  &rsp_pdu->dif_ctx))) {
2988 			rsp_pdu->dif_insert_or_strip = true;
2989 		}
2990 	}
2991 
2992 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_datain_pdu_complete, conn);
2993 
2994 	return DataSN;
2995 }
2996 
2997 static int
2998 iscsi_transfer_in(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
2999 {
3000 	uint32_t DataSN;
3001 	uint32_t transfer_len;
3002 	uint32_t data_len;
3003 	uint32_t segment_len;
3004 	uint32_t offset;
3005 	uint32_t residual_len = 0;
3006 	int sent_status;
3007 	uint32_t len;
3008 	int datain_flag = 0;
3009 	int datain_seq_cnt;
3010 	int i;
3011 	uint32_t sequence_end;
3012 	struct spdk_iscsi_task *primary;
3013 
3014 	primary = iscsi_task_get_primary(task);
3015 	segment_len = conn->MaxRecvDataSegmentLength;
3016 	data_len = task->scsi.data_transferred;
3017 	transfer_len = task->scsi.length;
3018 
3019 	if (task->scsi.status != SPDK_SCSI_STATUS_GOOD) {
3020 		return 0;
3021 	}
3022 
3023 	if (data_len < transfer_len) {
3024 		/* underflow */
3025 		SPDK_DEBUGLOG(iscsi, "Underflow %u/%u\n", data_len, transfer_len);
3026 		residual_len = transfer_len - data_len;
3027 		transfer_len = data_len;
3028 		datain_flag |= ISCSI_DATAIN_UNDERFLOW;
3029 	} else if (data_len > transfer_len) {
3030 		/* overflow */
3031 		SPDK_DEBUGLOG(iscsi, "Overflow %u/%u\n", data_len, transfer_len);
3032 		residual_len = data_len - transfer_len;
3033 		datain_flag |= ISCSI_DATAIN_OVERFLOW;
3034 	} else {
3035 		SPDK_DEBUGLOG(iscsi, "Transfer %u\n", transfer_len);
3036 		residual_len = 0;
3037 	}
3038 
3039 	DataSN = primary->datain_datasn;
3040 	sent_status = 0;
3041 
3042 	/* calculate the number of sequences for all data-in pdus */
3043 	datain_seq_cnt = 1 + ((transfer_len - 1) / (int)conn->sess->MaxBurstLength);
3044 	for (i = 0; i < datain_seq_cnt; i++) {
3045 		offset = i * conn->sess->MaxBurstLength;
3046 		sequence_end = spdk_min(((i + 1) * conn->sess->MaxBurstLength),
3047 					transfer_len);
3048 
3049 		/* send data splitted by segment_len */
3050 		for (; offset < sequence_end; offset += segment_len) {
3051 			len = spdk_min(segment_len, (sequence_end - offset));
3052 
3053 			datain_flag &= ~(ISCSI_FLAG_FINAL | ISCSI_DATAIN_STATUS);
3054 
3055 			if (offset + len == sequence_end) {
3056 				/* last PDU in a sequence */
3057 				datain_flag |= ISCSI_FLAG_FINAL;
3058 				if (task->scsi.sense_data_len == 0) {
3059 					/* The last pdu in all data-in pdus */
3060 					if ((offset + len) == transfer_len &&
3061 					    (primary->bytes_completed == primary->scsi.transfer_len)) {
3062 						datain_flag |= ISCSI_DATAIN_STATUS;
3063 						sent_status = 1;
3064 					}
3065 				}
3066 			}
3067 
3068 			SPDK_DEBUGLOG(iscsi, "Transfer=%d, Offset=%d, Len=%d\n",
3069 				      sequence_end, offset, len);
3070 			SPDK_DEBUGLOG(iscsi, "StatSN=%u, DataSN=%u, Offset=%u, Len=%d\n",
3071 				      conn->StatSN, DataSN, offset, len);
3072 
3073 			DataSN = iscsi_send_datain(conn, task, datain_flag, residual_len,
3074 						   offset, DataSN, len);
3075 		}
3076 	}
3077 
3078 	if (task != primary) {
3079 		primary->scsi.data_transferred += task->scsi.data_transferred;
3080 	}
3081 	primary->datain_datasn = DataSN;
3082 
3083 	return sent_status;
3084 }
3085 
3086 void iscsi_task_response(struct spdk_iscsi_conn *conn,
3087 			 struct spdk_iscsi_task *task)
3088 {
3089 	struct spdk_iscsi_pdu *rsp_pdu;
3090 	struct iscsi_bhs_scsi_resp *rsph;
3091 	uint32_t task_tag;
3092 	uint32_t transfer_len;
3093 	size_t residual_len;
3094 	size_t data_len;
3095 	int O_bit, U_bit;
3096 	int rc;
3097 	struct spdk_iscsi_task *primary;
3098 
3099 	primary = iscsi_task_get_primary(task);
3100 
3101 	transfer_len = primary->scsi.transfer_len;
3102 	task_tag = task->tag;
3103 
3104 	/* transfer data from logical unit */
3105 	/* (direction is view of initiator side) */
3106 	if (iscsi_task_is_read(primary)) {
3107 		rc = iscsi_transfer_in(conn, task);
3108 		if (rc > 0) {
3109 			/* sent status by last DATAIN PDU */
3110 			return;
3111 		}
3112 
3113 		if (primary->bytes_completed != primary->scsi.transfer_len) {
3114 			return;
3115 		}
3116 	}
3117 
3118 	O_bit = U_bit = 0;
3119 	residual_len = 0;
3120 	data_len = primary->scsi.data_transferred;
3121 
3122 	if ((transfer_len != 0) &&
3123 	    (task->scsi.status == SPDK_SCSI_STATUS_GOOD)) {
3124 		if (data_len < transfer_len) {
3125 			/* underflow */
3126 			SPDK_DEBUGLOG(iscsi, "Underflow %zu/%u\n", data_len, transfer_len);
3127 			residual_len = transfer_len - data_len;
3128 			U_bit = 1;
3129 		} else if (data_len > transfer_len) {
3130 			/* overflow */
3131 			SPDK_DEBUGLOG(iscsi, "Overflow %zu/%u\n", data_len, transfer_len);
3132 			residual_len = data_len - transfer_len;
3133 			O_bit = 1;
3134 		} else {
3135 			SPDK_DEBUGLOG(iscsi, "Transfer %u\n", transfer_len);
3136 		}
3137 	}
3138 
3139 	/* response PDU */
3140 	rsp_pdu = iscsi_get_pdu(conn);
3141 	assert(rsp_pdu != NULL);
3142 	rsph = (struct iscsi_bhs_scsi_resp *)&rsp_pdu->bhs;
3143 	assert(task->scsi.sense_data_len <= sizeof(rsp_pdu->sense.data));
3144 	memcpy(rsp_pdu->sense.data, task->scsi.sense_data, task->scsi.sense_data_len);
3145 	to_be16(&rsp_pdu->sense.length, task->scsi.sense_data_len);
3146 	rsp_pdu->data = (uint8_t *)&rsp_pdu->sense;
3147 	rsp_pdu->data_from_mempool = true;
3148 
3149 	/*
3150 	 * we need to hold onto this task/cmd because until the
3151 	 * PDU has been written out
3152 	 */
3153 	rsp_pdu->task = task;
3154 	task->scsi.ref++;
3155 
3156 	rsph->opcode = ISCSI_OP_SCSI_RSP;
3157 	rsph->flags |= 0x80; /* bit 0 is default to 1 */
3158 
3159 	if (O_bit) {
3160 		rsph->flags |= ISCSI_SCSI_OVERFLOW;
3161 	}
3162 
3163 	if (U_bit) {
3164 		rsph->flags |= ISCSI_SCSI_UNDERFLOW;
3165 	}
3166 
3167 	rsph->status = task->scsi.status;
3168 	if (task->scsi.sense_data_len) {
3169 		/* SenseLength (2 bytes) + SenseData  */
3170 		DSET24(rsph->data_segment_len, 2 + task->scsi.sense_data_len);
3171 	}
3172 	to_be32(&rsph->itt, task_tag);
3173 
3174 	to_be32(&rsph->stat_sn, conn->StatSN);
3175 	conn->StatSN++;
3176 
3177 	if (!iscsi_task_is_immediate(primary)) {
3178 		conn->sess->MaxCmdSN++;
3179 	}
3180 
3181 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
3182 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
3183 
3184 	to_be32(&rsph->bi_read_res_cnt, 0);
3185 	to_be32(&rsph->res_cnt, residual_len);
3186 
3187 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_pdu_generic_complete, NULL);
3188 }
3189 
3190 /*
3191  *  This function compare the input pdu's bhs with the pdu's bhs associated by
3192  *  active_r2t_tasks and queued_r2t_tasks in a connection
3193  */
3194 static bool
3195 iscsi_compare_pdu_bhs_within_existed_r2t_tasks(struct spdk_iscsi_conn *conn,
3196 		struct spdk_iscsi_pdu *pdu)
3197 {
3198 	struct spdk_iscsi_task	*task;
3199 
3200 	TAILQ_FOREACH(task, &conn->active_r2t_tasks, link) {
3201 		if (!memcmp(&pdu->bhs, iscsi_task_get_bhs(task), ISCSI_BHS_LEN)) {
3202 			return true;
3203 		}
3204 	}
3205 
3206 	TAILQ_FOREACH(task, &conn->queued_r2t_tasks, link) {
3207 		if (!memcmp(&pdu->bhs, iscsi_task_get_bhs(task), ISCSI_BHS_LEN)) {
3208 			return true;
3209 		}
3210 	}
3211 
3212 	return false;
3213 }
3214 
3215 void
3216 iscsi_queue_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
3217 {
3218 	spdk_trace_record(TRACE_ISCSI_TASK_QUEUE, conn->id, task->scsi.length,
3219 			  (uintptr_t)task, (uintptr_t)task->pdu);
3220 	task->is_queued = true;
3221 	spdk_scsi_dev_queue_task(conn->dev, &task->scsi);
3222 }
3223 
3224 static int
3225 iscsi_pdu_payload_op_scsi_read(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
3226 {
3227 	if (task->scsi.transfer_len <= SPDK_BDEV_LARGE_BUF_MAX_SIZE) {
3228 		task->parent = NULL;
3229 		task->scsi.offset = 0;
3230 		task->scsi.length = task->scsi.transfer_len;
3231 		spdk_scsi_task_set_data(&task->scsi, NULL, 0);
3232 
3233 		iscsi_queue_task(conn, task);
3234 		return 0;
3235 	} else {
3236 		TAILQ_INIT(&task->subtask_list);
3237 		task->current_datain_offset = 0;
3238 		TAILQ_INSERT_TAIL(&conn->queued_datain_tasks, task, link);
3239 
3240 		return iscsi_conn_handle_queued_datain_tasks(conn);
3241 	}
3242 }
3243 
3244 static int
3245 iscsi_pdu_payload_op_scsi_write(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
3246 {
3247 	struct spdk_iscsi_pdu *pdu;
3248 	struct iscsi_bhs_scsi_req *reqh;
3249 	uint32_t transfer_len;
3250 	uint32_t scsi_data_len;
3251 	int rc;
3252 
3253 	pdu = iscsi_task_get_pdu(task);
3254 	reqh = (struct iscsi_bhs_scsi_req *)&pdu->bhs;
3255 
3256 	transfer_len = task->scsi.transfer_len;
3257 
3258 	if (spdk_likely(!pdu->dif_insert_or_strip)) {
3259 		scsi_data_len = pdu->data_segment_len;
3260 	} else {
3261 		scsi_data_len = pdu->data_buf_len;
3262 	}
3263 
3264 	if (reqh->final_bit &&
3265 	    pdu->data_segment_len < transfer_len) {
3266 		/* needs R2T */
3267 		rc = add_transfer_task(conn, task);
3268 		if (rc < 0) {
3269 			SPDK_ERRLOG("add_transfer_task() failed\n");
3270 			iscsi_task_put(task);
3271 			return SPDK_ISCSI_CONNECTION_FATAL;
3272 		}
3273 
3274 		/* Non-immediate writes */
3275 		if (pdu->data_segment_len == 0) {
3276 			return 0;
3277 		} else {
3278 			/* we are doing the first partial write task */
3279 			task->scsi.ref++;
3280 			spdk_scsi_task_set_data(&task->scsi, pdu->data, scsi_data_len);
3281 			task->scsi.length = pdu->data_segment_len;
3282 		}
3283 	}
3284 
3285 	if (pdu->data_segment_len == transfer_len) {
3286 		/* we are doing small writes with no R2T */
3287 		spdk_scsi_task_set_data(&task->scsi, pdu->data, scsi_data_len);
3288 		task->scsi.length = transfer_len;
3289 	}
3290 
3291 	iscsi_queue_task(conn, task);
3292 	return 0;
3293 }
3294 
3295 static int
3296 iscsi_pdu_hdr_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3297 {
3298 	struct spdk_iscsi_task	*task;
3299 	struct spdk_scsi_dev	*dev;
3300 	uint8_t *cdb;
3301 	uint64_t lun;
3302 	uint32_t task_tag;
3303 	uint32_t transfer_len;
3304 	int R_bit, W_bit;
3305 	int lun_i;
3306 	struct iscsi_bhs_scsi_req *reqh;
3307 
3308 	if (conn->sess->session_type != SESSION_TYPE_NORMAL) {
3309 		SPDK_ERRLOG("ISCSI_OP_SCSI not allowed in discovery and invalid session\n");
3310 		return SPDK_ISCSI_CONNECTION_FATAL;
3311 	}
3312 
3313 	reqh = (struct iscsi_bhs_scsi_req *)&pdu->bhs;
3314 
3315 	R_bit = reqh->read_bit;
3316 	W_bit = reqh->write_bit;
3317 	lun = from_be64(&reqh->lun);
3318 	task_tag = from_be32(&reqh->itt);
3319 	transfer_len = from_be32(&reqh->expected_data_xfer_len);
3320 	cdb = reqh->cdb;
3321 
3322 	SPDK_LOGDUMP(iscsi, "CDB", cdb, 16);
3323 
3324 	task = iscsi_task_get(conn, NULL, iscsi_task_cpl);
3325 	if (!task) {
3326 		SPDK_ERRLOG("Unable to acquire task\n");
3327 		return SPDK_ISCSI_CONNECTION_FATAL;
3328 	}
3329 
3330 	iscsi_task_associate_pdu(task, pdu);
3331 	lun_i = spdk_scsi_lun_id_fmt_to_int(lun);
3332 	task->lun_id = lun_i;
3333 	dev = conn->dev;
3334 	task->scsi.lun = spdk_scsi_dev_get_lun(dev, lun_i);
3335 
3336 	if ((R_bit != 0) && (W_bit != 0)) {
3337 		SPDK_ERRLOG("Bidirectional CDB is not supported\n");
3338 		iscsi_task_put(task);
3339 		return SPDK_ISCSI_CONNECTION_FATAL;
3340 	}
3341 
3342 	task->scsi.cdb = cdb;
3343 	task->tag = task_tag;
3344 	task->scsi.transfer_len = transfer_len;
3345 	task->scsi.target_port = conn->target_port;
3346 	task->scsi.initiator_port = conn->initiator_port;
3347 	task->parent = NULL;
3348 	task->rsp_scsi_status = SPDK_SCSI_STATUS_GOOD;
3349 
3350 	if (task->scsi.lun == NULL) {
3351 		spdk_scsi_task_process_null_lun(&task->scsi);
3352 		iscsi_task_cpl(&task->scsi);
3353 		return 0;
3354 	}
3355 
3356 	/* no bi-directional support */
3357 	if (R_bit) {
3358 		task->scsi.dxfer_dir = SPDK_SCSI_DIR_FROM_DEV;
3359 	} else if (W_bit) {
3360 		task->scsi.dxfer_dir = SPDK_SCSI_DIR_TO_DEV;
3361 
3362 		if ((conn->sess->ErrorRecoveryLevel >= 1) &&
3363 		    (iscsi_compare_pdu_bhs_within_existed_r2t_tasks(conn, pdu))) {
3364 			iscsi_task_response(conn, task);
3365 			iscsi_task_put(task);
3366 			return 0;
3367 		}
3368 
3369 		if (pdu->data_segment_len > iscsi_get_max_immediate_data_size()) {
3370 			SPDK_ERRLOG("data segment len(=%zu) > immediate data len(=%"PRIu32")\n",
3371 				    pdu->data_segment_len, iscsi_get_max_immediate_data_size());
3372 			iscsi_task_put(task);
3373 			return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3374 		}
3375 
3376 		if (pdu->data_segment_len > transfer_len) {
3377 			SPDK_ERRLOG("data segment len(=%zu) > task transfer len(=%d)\n",
3378 				    pdu->data_segment_len, transfer_len);
3379 			iscsi_task_put(task);
3380 			return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3381 		}
3382 
3383 		/* check the ImmediateData and also pdu->data_segment_len */
3384 		if ((!conn->sess->ImmediateData && (pdu->data_segment_len > 0)) ||
3385 		    (pdu->data_segment_len > conn->sess->FirstBurstLength)) {
3386 			iscsi_task_put(task);
3387 			return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3388 		}
3389 
3390 		if (spdk_unlikely(spdk_scsi_lun_get_dif_ctx(task->scsi.lun, &task->scsi, &pdu->dif_ctx))) {
3391 			pdu->dif_insert_or_strip = true;
3392 		}
3393 	} else {
3394 		/* neither R nor W bit set */
3395 		task->scsi.dxfer_dir = SPDK_SCSI_DIR_NONE;
3396 		if (transfer_len > 0) {
3397 			iscsi_task_put(task);
3398 			SPDK_ERRLOG("Reject scsi cmd with EDTL > 0 but (R | W) == 0\n");
3399 			return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_PDU_FIELD);
3400 		}
3401 	}
3402 
3403 	pdu->task = task;
3404 	return 0;
3405 }
3406 
3407 static int
3408 iscsi_pdu_payload_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3409 {
3410 	struct spdk_iscsi_task *task;
3411 
3412 	if (pdu->task == NULL) {
3413 		return 0;
3414 	}
3415 
3416 	task = pdu->task;
3417 
3418 	if (spdk_scsi_dev_get_lun(conn->dev, task->lun_id) == NULL) {
3419 		spdk_scsi_task_process_null_lun(&task->scsi);
3420 		iscsi_task_cpl(&task->scsi);
3421 		return 0;
3422 	}
3423 
3424 	switch (task->scsi.dxfer_dir) {
3425 	case SPDK_SCSI_DIR_FROM_DEV:
3426 		return iscsi_pdu_payload_op_scsi_read(conn, task);
3427 	case SPDK_SCSI_DIR_TO_DEV:
3428 		return iscsi_pdu_payload_op_scsi_write(conn, task);
3429 	case SPDK_SCSI_DIR_NONE:
3430 		iscsi_queue_task(conn, task);
3431 		return 0;
3432 	default:
3433 		assert(false);
3434 		iscsi_task_put(task);
3435 		break;
3436 	}
3437 
3438 	return SPDK_ISCSI_CONNECTION_FATAL;
3439 }
3440 
3441 void
3442 iscsi_task_mgmt_response(struct spdk_iscsi_conn *conn,
3443 			 struct spdk_iscsi_task *task)
3444 {
3445 	struct spdk_iscsi_pdu *rsp_pdu;
3446 	struct iscsi_bhs_task_req *reqh;
3447 	struct iscsi_bhs_task_resp *rsph;
3448 
3449 	if (task->pdu == NULL) {
3450 		/*
3451 		 * This was an internally generated task management command,
3452 		 *  usually from LUN cleanup when a connection closes.
3453 		 */
3454 		return;
3455 	}
3456 
3457 	reqh = (struct iscsi_bhs_task_req *)&task->pdu->bhs;
3458 	/* response PDU */
3459 	rsp_pdu = iscsi_get_pdu(conn);
3460 	rsph = (struct iscsi_bhs_task_resp *)&rsp_pdu->bhs;
3461 	rsph->opcode = ISCSI_OP_TASK_RSP;
3462 	rsph->flags |= 0x80; /* bit 0 default to 1 */
3463 	switch (task->scsi.response) {
3464 	case SPDK_SCSI_TASK_MGMT_RESP_COMPLETE:
3465 		rsph->response = ISCSI_TASK_FUNC_RESP_COMPLETE;
3466 		break;
3467 	case SPDK_SCSI_TASK_MGMT_RESP_SUCCESS:
3468 		rsph->response = ISCSI_TASK_FUNC_RESP_COMPLETE;
3469 		break;
3470 	case SPDK_SCSI_TASK_MGMT_RESP_REJECT:
3471 		rsph->response = ISCSI_TASK_FUNC_REJECTED;
3472 		break;
3473 	case SPDK_SCSI_TASK_MGMT_RESP_INVALID_LUN:
3474 		rsph->response = ISCSI_TASK_FUNC_RESP_LUN_NOT_EXIST;
3475 		break;
3476 	case SPDK_SCSI_TASK_MGMT_RESP_TARGET_FAILURE:
3477 		rsph->response = ISCSI_TASK_FUNC_REJECTED;
3478 		break;
3479 	case SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED:
3480 		rsph->response = ISCSI_TASK_FUNC_RESP_FUNC_NOT_SUPPORTED;
3481 		break;
3482 	}
3483 	rsph->itt = reqh->itt;
3484 
3485 	to_be32(&rsph->stat_sn, conn->StatSN);
3486 	conn->StatSN++;
3487 
3488 	if (reqh->immediate == 0) {
3489 		conn->sess->MaxCmdSN++;
3490 	}
3491 
3492 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
3493 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
3494 
3495 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_pdu_generic_complete, NULL);
3496 }
3497 
3498 static void
3499 iscsi_queue_mgmt_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task)
3500 {
3501 	struct spdk_scsi_lun *lun;
3502 
3503 	lun = spdk_scsi_dev_get_lun(conn->dev, task->lun_id);
3504 	if (lun == NULL) {
3505 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_INVALID_LUN;
3506 		iscsi_task_mgmt_response(conn, task);
3507 		iscsi_task_put(task);
3508 		return;
3509 	}
3510 
3511 	spdk_scsi_dev_queue_mgmt_task(conn->dev, &task->scsi);
3512 }
3513 
3514 static int
3515 _iscsi_op_abort_task(void *arg)
3516 {
3517 	struct spdk_iscsi_task *task = arg;
3518 	int rc;
3519 
3520 	rc = iscsi_conn_abort_queued_datain_task(task->conn, task->scsi.abort_id);
3521 	if (rc != 0) {
3522 		return SPDK_POLLER_BUSY;
3523 	}
3524 
3525 	spdk_poller_unregister(&task->mgmt_poller);
3526 	iscsi_queue_mgmt_task(task->conn, task);
3527 	return SPDK_POLLER_BUSY;
3528 }
3529 
3530 static void
3531 iscsi_op_abort_task(struct spdk_iscsi_task *task, uint32_t ref_task_tag)
3532 {
3533 	task->scsi.abort_id = ref_task_tag;
3534 	task->scsi.function = SPDK_SCSI_TASK_FUNC_ABORT_TASK;
3535 	task->mgmt_poller = SPDK_POLLER_REGISTER(_iscsi_op_abort_task, task, 10);
3536 }
3537 
3538 static int
3539 _iscsi_op_abort_task_set(void *arg)
3540 {
3541 	struct spdk_iscsi_task *task = arg;
3542 	int rc;
3543 
3544 	rc = iscsi_conn_abort_queued_datain_tasks(task->conn, task->scsi.lun,
3545 			task->pdu);
3546 	if (rc != 0) {
3547 		return SPDK_POLLER_BUSY;
3548 	}
3549 
3550 	spdk_poller_unregister(&task->mgmt_poller);
3551 	iscsi_queue_mgmt_task(task->conn, task);
3552 	return SPDK_POLLER_BUSY;
3553 }
3554 
3555 void
3556 iscsi_op_abort_task_set(struct spdk_iscsi_task *task, uint8_t function)
3557 {
3558 	task->scsi.function = function;
3559 	task->mgmt_poller = SPDK_POLLER_REGISTER(_iscsi_op_abort_task_set, task, 10);
3560 }
3561 
3562 static int
3563 iscsi_pdu_hdr_op_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3564 {
3565 	struct iscsi_bhs_task_req *reqh;
3566 	uint64_t lun;
3567 	uint32_t task_tag;
3568 	uint32_t ref_task_tag;
3569 	uint8_t function;
3570 	int lun_i;
3571 	struct spdk_iscsi_task *task;
3572 	struct spdk_scsi_dev *dev;
3573 
3574 	if (conn->sess->session_type != SESSION_TYPE_NORMAL) {
3575 		SPDK_ERRLOG("ISCSI_OP_TASK not allowed in discovery and invalid session\n");
3576 		return SPDK_ISCSI_CONNECTION_FATAL;
3577 	}
3578 
3579 	reqh = (struct iscsi_bhs_task_req *)&pdu->bhs;
3580 	function = reqh->flags & ISCSI_TASK_FUNCTION_MASK;
3581 	lun = from_be64(&reqh->lun);
3582 	task_tag = from_be32(&reqh->itt);
3583 	ref_task_tag = from_be32(&reqh->ref_task_tag);
3584 
3585 	SPDK_DEBUGLOG(iscsi, "I=%d, func=%d, ITT=%x, ref TT=%x, LUN=0x%16.16"PRIx64"\n",
3586 		      reqh->immediate, function, task_tag, ref_task_tag, lun);
3587 
3588 	SPDK_DEBUGLOG(iscsi, "StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
3589 		      conn->StatSN, conn->sess->ExpCmdSN, conn->sess->MaxCmdSN);
3590 
3591 	lun_i = spdk_scsi_lun_id_fmt_to_int(lun);
3592 	dev = conn->dev;
3593 
3594 	task = iscsi_task_get(conn, NULL, iscsi_task_mgmt_cpl);
3595 	if (!task) {
3596 		SPDK_ERRLOG("Unable to acquire task\n");
3597 		return SPDK_ISCSI_CONNECTION_FATAL;
3598 	}
3599 
3600 	iscsi_task_associate_pdu(task, pdu);
3601 	task->scsi.target_port = conn->target_port;
3602 	task->scsi.initiator_port = conn->initiator_port;
3603 	task->tag = task_tag;
3604 	task->scsi.lun = spdk_scsi_dev_get_lun(dev, lun_i);
3605 	task->lun_id = lun_i;
3606 
3607 	if (task->scsi.lun == NULL) {
3608 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_INVALID_LUN;
3609 		iscsi_task_mgmt_response(conn, task);
3610 		iscsi_task_put(task);
3611 		return 0;
3612 	}
3613 
3614 	switch (function) {
3615 	/* abort task identified by Referenced Task Tag field */
3616 	case ISCSI_TASK_FUNC_ABORT_TASK:
3617 		SPDK_NOTICELOG("ABORT_TASK\n");
3618 
3619 		iscsi_del_transfer_task(conn, ref_task_tag);
3620 		iscsi_op_abort_task(task, ref_task_tag);
3621 		return 0;
3622 
3623 	/* abort all tasks issued via this session on the LUN */
3624 	case ISCSI_TASK_FUNC_ABORT_TASK_SET:
3625 		SPDK_NOTICELOG("ABORT_TASK_SET\n");
3626 
3627 		iscsi_clear_all_transfer_task(conn, task->scsi.lun, pdu);
3628 		iscsi_op_abort_task_set(task, SPDK_SCSI_TASK_FUNC_ABORT_TASK_SET);
3629 		return 0;
3630 
3631 	case ISCSI_TASK_FUNC_CLEAR_TASK_SET:
3632 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3633 		SPDK_NOTICELOG("CLEAR_TASK_SET (Unsupported)\n");
3634 		break;
3635 
3636 	case ISCSI_TASK_FUNC_CLEAR_ACA:
3637 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3638 		SPDK_NOTICELOG("CLEAR_ACA (Unsupported)\n");
3639 		break;
3640 
3641 	case ISCSI_TASK_FUNC_LOGICAL_UNIT_RESET:
3642 		SPDK_NOTICELOG("LOGICAL_UNIT_RESET\n");
3643 
3644 		iscsi_clear_all_transfer_task(conn, task->scsi.lun, pdu);
3645 		iscsi_op_abort_task_set(task, SPDK_SCSI_TASK_FUNC_LUN_RESET);
3646 		return 0;
3647 
3648 	case ISCSI_TASK_FUNC_TARGET_WARM_RESET:
3649 		SPDK_NOTICELOG("TARGET_WARM_RESET (Unsupported)\n");
3650 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3651 		break;
3652 
3653 	case ISCSI_TASK_FUNC_TARGET_COLD_RESET:
3654 		SPDK_NOTICELOG("TARGET_COLD_RESET (Unsupported)\n");
3655 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3656 		break;
3657 
3658 	case ISCSI_TASK_FUNC_TASK_REASSIGN:
3659 		SPDK_NOTICELOG("TASK_REASSIGN (Unsupported)\n");
3660 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT_FUNC_NOT_SUPPORTED;
3661 		break;
3662 
3663 	default:
3664 		SPDK_ERRLOG("unsupported function %d\n", function);
3665 		task->scsi.response = SPDK_SCSI_TASK_MGMT_RESP_REJECT;
3666 		break;
3667 	}
3668 
3669 	iscsi_task_mgmt_response(conn, task);
3670 	iscsi_task_put(task);
3671 	return 0;
3672 }
3673 
3674 static int
3675 iscsi_pdu_hdr_op_nopout(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3676 {
3677 	struct iscsi_bhs_nop_out *reqh;
3678 	uint32_t task_tag;
3679 	uint32_t transfer_tag;
3680 	int I_bit;
3681 
3682 	if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
3683 		SPDK_ERRLOG("ISCSI_OP_NOPOUT not allowed in discovery session\n");
3684 		return SPDK_ISCSI_CONNECTION_FATAL;
3685 	}
3686 
3687 	reqh = (struct iscsi_bhs_nop_out *)&pdu->bhs;
3688 	I_bit = reqh->immediate;
3689 
3690 	if (pdu->data_segment_len > SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH) {
3691 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3692 	}
3693 
3694 	task_tag = from_be32(&reqh->itt);
3695 	transfer_tag = from_be32(&reqh->ttt);
3696 
3697 	SPDK_DEBUGLOG(iscsi, "I=%d, ITT=%x, TTT=%x\n",
3698 		      I_bit, task_tag, transfer_tag);
3699 
3700 	SPDK_DEBUGLOG(iscsi, "CmdSN=%u, StatSN=%u, ExpCmdSN=%u, MaxCmdSN=%u\n",
3701 		      pdu->cmd_sn, conn->StatSN, conn->sess->ExpCmdSN,
3702 		      conn->sess->MaxCmdSN);
3703 
3704 	if (transfer_tag != 0xFFFFFFFF && transfer_tag != (uint32_t)conn->id) {
3705 		SPDK_ERRLOG("invalid transfer tag 0x%x\n", transfer_tag);
3706 		/*
3707 		 * Technically we should probably fail the connection here, but for now
3708 		 *  just print the error message and continue.
3709 		 */
3710 	}
3711 
3712 	if (task_tag == 0xffffffffU && I_bit == 0) {
3713 		SPDK_ERRLOG("got NOPOUT ITT=0xffffffff, I=0\n");
3714 		return SPDK_ISCSI_CONNECTION_FATAL;
3715 	}
3716 
3717 	return 0;
3718 }
3719 
3720 static int
3721 iscsi_pdu_payload_op_nopout(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3722 {
3723 	struct spdk_iscsi_pdu *rsp_pdu;
3724 	struct iscsi_bhs_nop_out *reqh;
3725 	struct iscsi_bhs_nop_in *rsph;
3726 	uint8_t *data;
3727 	uint64_t lun;
3728 	uint32_t task_tag;
3729 	int I_bit;
3730 	int data_len;
3731 
3732 	reqh = (struct iscsi_bhs_nop_out *)&pdu->bhs;
3733 	I_bit = reqh->immediate;
3734 
3735 	data_len = pdu->data_segment_len;
3736 	if (data_len > conn->MaxRecvDataSegmentLength) {
3737 		data_len = conn->MaxRecvDataSegmentLength;
3738 	}
3739 
3740 	lun = from_be64(&reqh->lun);
3741 	task_tag = from_be32(&reqh->itt);
3742 
3743 	/*
3744 	 * We don't actually check to see if this is a response to the NOP-In
3745 	 * that we sent.  Our goal is to just verify that the initiator is
3746 	 * alive and responding to commands, not to verify that it tags
3747 	 * NOP-Outs correctly
3748 	 */
3749 	conn->nop_outstanding = false;
3750 
3751 	if (task_tag == 0xffffffffU) {
3752 		assert(I_bit == 1);
3753 		SPDK_DEBUGLOG(iscsi, "got NOPOUT ITT=0xffffffff\n");
3754 		return 0;
3755 	}
3756 
3757 	data = calloc(1, data_len);
3758 	if (!data) {
3759 		SPDK_ERRLOG("calloc() failed for ping data\n");
3760 		return SPDK_ISCSI_CONNECTION_FATAL;
3761 	}
3762 
3763 	/* response of NOPOUT */
3764 	if (data_len > 0) {
3765 		/* copy ping data */
3766 		memcpy(data, pdu->data, data_len);
3767 	}
3768 
3769 	/* response PDU */
3770 	rsp_pdu = iscsi_get_pdu(conn);
3771 	assert(rsp_pdu != NULL);
3772 
3773 	rsph = (struct iscsi_bhs_nop_in *)&rsp_pdu->bhs;
3774 	rsp_pdu->data = data;
3775 	rsph->opcode = ISCSI_OP_NOPIN;
3776 	rsph->flags |= 0x80; /* bit 0 default to 1 */
3777 	DSET24(rsph->data_segment_len, data_len);
3778 	to_be64(&rsph->lun, lun);
3779 	to_be32(&rsph->itt, task_tag);
3780 	to_be32(&rsph->ttt, 0xffffffffU);
3781 
3782 	to_be32(&rsph->stat_sn, conn->StatSN);
3783 	conn->StatSN++;
3784 
3785 	if (I_bit == 0) {
3786 		conn->sess->MaxCmdSN++;
3787 	}
3788 
3789 	to_be32(&rsph->exp_cmd_sn, conn->sess->ExpCmdSN);
3790 	to_be32(&rsph->max_cmd_sn, conn->sess->MaxCmdSN);
3791 
3792 	iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_pdu_generic_complete, NULL);
3793 	conn->last_nopin = spdk_get_ticks();
3794 
3795 	return 0;
3796 }
3797 
3798 /* This function returns the spdk_scsi_task by searching the snack list via
3799  * task transfertag and the pdu's opcode
3800  */
3801 static struct spdk_iscsi_task *
3802 get_scsi_task_from_ttt(struct spdk_iscsi_conn *conn, uint32_t transfer_tag)
3803 {
3804 	struct spdk_iscsi_pdu *pdu;
3805 	struct iscsi_bhs_data_in *datain_bhs;
3806 
3807 	TAILQ_FOREACH(pdu, &conn->snack_pdu_list, tailq) {
3808 		if (pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
3809 			datain_bhs = (struct iscsi_bhs_data_in *)&pdu->bhs;
3810 			if (from_be32(&datain_bhs->ttt) == transfer_tag) {
3811 				return pdu->task;
3812 			}
3813 		}
3814 	}
3815 
3816 	return NULL;
3817 }
3818 
3819 /* This function returns the spdk_scsi_task by searching the snack list via
3820  * initiator task tag and the pdu's opcode
3821  */
3822 static struct spdk_iscsi_task *
3823 get_scsi_task_from_itt(struct spdk_iscsi_conn *conn,
3824 		       uint32_t task_tag, enum iscsi_op opcode)
3825 {
3826 	struct spdk_iscsi_pdu *pdu;
3827 
3828 	TAILQ_FOREACH(pdu, &conn->snack_pdu_list, tailq) {
3829 		if (pdu->bhs.opcode == opcode &&
3830 		    pdu->task != NULL &&
3831 		    pdu->task->tag == task_tag) {
3832 			return pdu->task;
3833 		}
3834 	}
3835 
3836 	return NULL;
3837 }
3838 
3839 /* This function is used to handle the r2t snack */
3840 static int
3841 iscsi_handle_r2t_snack(struct spdk_iscsi_conn *conn,
3842 		       struct spdk_iscsi_task *task,
3843 		       struct spdk_iscsi_pdu *pdu, uint32_t beg_run,
3844 		       uint32_t run_length, int32_t task_tag)
3845 {
3846 	int32_t last_r2tsn;
3847 	int i;
3848 
3849 	if (beg_run < task->acked_r2tsn) {
3850 		SPDK_ERRLOG("ITT: 0x%08x, R2T SNACK requests retransmission of"
3851 			    "R2TSN: from 0x%08x to 0x%08x. But it has already"
3852 			    "ack to R2TSN:0x%08x, protocol error.\n",
3853 			    task_tag, beg_run, (beg_run + run_length),
3854 			    (task->acked_r2tsn - 1));
3855 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3856 	}
3857 
3858 	if (run_length) {
3859 		if ((beg_run + run_length) > task->R2TSN) {
3860 			SPDK_ERRLOG("ITT: 0x%08x, received R2T SNACK with"
3861 				    "BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
3862 				    "current R2TSN: 0x%08x, protocol error.\n",
3863 				    task_tag, beg_run, run_length,
3864 				    task->R2TSN);
3865 
3866 			return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_PDU_FIELD);
3867 		}
3868 		last_r2tsn = (beg_run + run_length);
3869 	} else {
3870 		last_r2tsn = task->R2TSN;
3871 	}
3872 
3873 	for (i = beg_run; i < last_r2tsn; i++) {
3874 		if (iscsi_send_r2t_recovery(conn, task, i, false) < 0) {
3875 			SPDK_ERRLOG("The r2t_sn=%d of r2t_task=%p is not sent\n", i, task);
3876 		}
3877 	}
3878 	return 0;
3879 }
3880 
3881 /* This function is used to recover the data in packet */
3882 static int
3883 iscsi_handle_recovery_datain(struct spdk_iscsi_conn *conn,
3884 			     struct spdk_iscsi_task *task,
3885 			     struct spdk_iscsi_pdu *pdu, uint32_t beg_run,
3886 			     uint32_t run_length, uint32_t task_tag)
3887 {
3888 	struct spdk_iscsi_pdu *old_pdu, *pdu_temp;
3889 	uint32_t i;
3890 	struct iscsi_bhs_data_in *datain_header;
3891 	uint32_t last_statsn;
3892 
3893 	task = iscsi_task_get_primary(task);
3894 
3895 	SPDK_DEBUGLOG(iscsi, "iscsi_handle_recovery_datain\n");
3896 
3897 	if (beg_run < task->acked_data_sn) {
3898 		SPDK_ERRLOG("ITT: 0x%08x, DATA IN SNACK requests retransmission of"
3899 			    "DATASN: from 0x%08x to 0x%08x but already acked to "
3900 			    "DATASN: 0x%08x protocol error\n",
3901 			    task_tag, beg_run,
3902 			    (beg_run + run_length), (task->acked_data_sn - 1));
3903 
3904 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
3905 	}
3906 
3907 	if (run_length == 0) {
3908 		/* as the DataSN begins at 0 */
3909 		run_length = task->datain_datasn + 1;
3910 	}
3911 
3912 	if ((beg_run + run_length - 1) > task->datain_datasn) {
3913 		SPDK_ERRLOG("Initiator requests BegRun: 0x%08x, RunLength:"
3914 			    "0x%08x greater than maximum DataSN: 0x%08x.\n",
3915 			    beg_run, run_length, task->datain_datasn);
3916 
3917 		return -1;
3918 	} else {
3919 		last_statsn = beg_run + run_length - 1;
3920 	}
3921 
3922 	for (i = beg_run; i <= last_statsn; i++) {
3923 		TAILQ_FOREACH_SAFE(old_pdu, &conn->snack_pdu_list, tailq, pdu_temp) {
3924 			if (old_pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
3925 				datain_header = (struct iscsi_bhs_data_in *)&old_pdu->bhs;
3926 				if (from_be32(&datain_header->itt) == task_tag &&
3927 				    from_be32(&datain_header->data_sn) == i) {
3928 					TAILQ_REMOVE(&conn->snack_pdu_list, old_pdu, tailq);
3929 					iscsi_conn_write_pdu(conn, old_pdu, old_pdu->cb_fn, old_pdu->cb_arg);
3930 					break;
3931 				}
3932 			}
3933 		}
3934 	}
3935 	return 0;
3936 }
3937 
3938 /* This function is used to handle the status snack */
3939 static int
3940 iscsi_handle_status_snack(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3941 {
3942 	uint32_t beg_run;
3943 	uint32_t run_length;
3944 	struct iscsi_bhs_snack_req *reqh;
3945 	uint32_t i;
3946 	uint32_t last_statsn;
3947 	bool found_pdu;
3948 	struct spdk_iscsi_pdu *old_pdu;
3949 
3950 	reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
3951 	beg_run = from_be32(&reqh->beg_run);
3952 	run_length = from_be32(&reqh->run_len);
3953 
3954 	SPDK_DEBUGLOG(iscsi, "beg_run=%d, run_length=%d, conn->StatSN="
3955 		      "%d, conn->exp_statsn=%d\n", beg_run, run_length,
3956 		      conn->StatSN, conn->exp_statsn);
3957 
3958 	if (!beg_run) {
3959 		beg_run = conn->exp_statsn;
3960 	} else if (beg_run < conn->exp_statsn) {
3961 		SPDK_ERRLOG("Got Status SNACK Begrun: 0x%08x, RunLength: 0x%08x "
3962 			    "but already got ExpStatSN: 0x%08x on CID:%hu.\n",
3963 			    beg_run, run_length, conn->StatSN, conn->cid);
3964 
3965 		return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_PDU_FIELD);
3966 	}
3967 
3968 	last_statsn = (!run_length) ? conn->StatSN : (beg_run + run_length);
3969 
3970 	for (i = beg_run; i < last_statsn; i++) {
3971 		found_pdu = false;
3972 		TAILQ_FOREACH(old_pdu, &conn->snack_pdu_list, tailq) {
3973 			if (from_be32(&old_pdu->bhs.stat_sn) == i) {
3974 				found_pdu = true;
3975 				break;
3976 			}
3977 		}
3978 
3979 		if (!found_pdu) {
3980 			SPDK_ERRLOG("Unable to find StatSN: 0x%08x. For a Status"
3981 				    "SNACK, assuming this is a proactive SNACK "
3982 				    "for an untransmitted StatSN, ignoring.\n",
3983 				    beg_run);
3984 		} else {
3985 			TAILQ_REMOVE(&conn->snack_pdu_list, old_pdu, tailq);
3986 			iscsi_conn_write_pdu(conn, old_pdu, old_pdu->cb_fn, old_pdu->cb_arg);
3987 		}
3988 	}
3989 
3990 	return 0;
3991 }
3992 
3993 /* This function is used to handle the data ack snack */
3994 static int
3995 iscsi_handle_data_ack(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
3996 {
3997 	uint32_t transfer_tag;
3998 	uint32_t beg_run;
3999 	uint32_t run_length;
4000 	struct spdk_iscsi_pdu *old_pdu;
4001 	uint32_t old_datasn;
4002 	struct iscsi_bhs_snack_req *reqh;
4003 	struct spdk_iscsi_task *task;
4004 	struct iscsi_bhs_data_in *datain_header;
4005 	struct spdk_iscsi_task *primary;
4006 
4007 	reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
4008 	transfer_tag = from_be32(&reqh->ttt);
4009 	beg_run = from_be32(&reqh->beg_run);
4010 	run_length = from_be32(&reqh->run_len);
4011 	task = NULL;
4012 	datain_header = NULL;
4013 
4014 	SPDK_DEBUGLOG(iscsi, "beg_run=%d,transfer_tag=%d,run_len=%d\n",
4015 		      beg_run, transfer_tag, run_length);
4016 
4017 	task = get_scsi_task_from_ttt(conn, transfer_tag);
4018 	if (!task) {
4019 		SPDK_ERRLOG("Data ACK SNACK for TTT: 0x%08x is invalid.\n",
4020 			    transfer_tag);
4021 		goto reject_return;
4022 	}
4023 
4024 	primary = iscsi_task_get_primary(task);
4025 	if ((run_length != 0) || (beg_run < primary->acked_data_sn)) {
4026 		SPDK_ERRLOG("TTT: 0x%08x Data ACK SNACK BegRUN: %d is less than "
4027 			    "the next expected acked DataSN: %d\n",
4028 			    transfer_tag, beg_run, primary->acked_data_sn);
4029 		goto reject_return;
4030 	}
4031 
4032 	primary->acked_data_sn = beg_run;
4033 
4034 	/* To free the pdu */
4035 	TAILQ_FOREACH(old_pdu, &conn->snack_pdu_list, tailq) {
4036 		if (old_pdu->bhs.opcode == ISCSI_OP_SCSI_DATAIN) {
4037 			datain_header = (struct iscsi_bhs_data_in *) &old_pdu->bhs;
4038 			old_datasn = from_be32(&datain_header->data_sn);
4039 			if ((from_be32(&datain_header->ttt) == transfer_tag) &&
4040 			    (old_datasn == beg_run - 1)) {
4041 				TAILQ_REMOVE(&conn->snack_pdu_list, old_pdu, tailq);
4042 				iscsi_conn_free_pdu(conn, old_pdu);
4043 				break;
4044 			}
4045 		}
4046 	}
4047 
4048 	SPDK_DEBUGLOG(iscsi, "Received Data ACK SNACK for TTT: 0x%08x,"
4049 		      " updated acked DataSN to 0x%08x.\n", transfer_tag,
4050 		      (task->acked_data_sn - 1));
4051 
4052 	return 0;
4053 
4054 reject_return:
4055 	return iscsi_reject(conn, pdu, ISCSI_REASON_INVALID_SNACK);
4056 }
4057 
4058 /* This function is used to handle the snack request from the initiator */
4059 static int
4060 iscsi_pdu_hdr_op_snack(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4061 {
4062 	struct iscsi_bhs_snack_req *reqh;
4063 	struct spdk_iscsi_task *task;
4064 	int type;
4065 	uint32_t task_tag;
4066 	uint32_t beg_run;
4067 	uint32_t run_length;
4068 	int rc;
4069 
4070 	if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
4071 		SPDK_ERRLOG("ISCSI_OP_SNACK not allowed in  discovery session\n");
4072 		return SPDK_ISCSI_CONNECTION_FATAL;
4073 	}
4074 
4075 	reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
4076 	if (!conn->sess->ErrorRecoveryLevel) {
4077 		SPDK_ERRLOG("Got a SNACK request in ErrorRecoveryLevel=0\n");
4078 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4079 	}
4080 
4081 	type = reqh->flags & ISCSI_FLAG_SNACK_TYPE_MASK;
4082 	SPDK_DEBUGLOG(iscsi, "The value of type is %d\n", type);
4083 
4084 	switch (type) {
4085 	case 0:
4086 		reqh = (struct iscsi_bhs_snack_req *)&pdu->bhs;
4087 		task_tag = from_be32(&reqh->itt);
4088 		beg_run = from_be32(&reqh->beg_run);
4089 		run_length = from_be32(&reqh->run_len);
4090 
4091 		SPDK_DEBUGLOG(iscsi, "beg_run=%d, run_length=%d, "
4092 			      "task_tag=%x, transfer_tag=%u\n", beg_run,
4093 			      run_length, task_tag, from_be32(&reqh->ttt));
4094 
4095 		task = get_scsi_task_from_itt(conn, task_tag,
4096 					      ISCSI_OP_SCSI_DATAIN);
4097 		if (task) {
4098 			return iscsi_handle_recovery_datain(conn, task, pdu,
4099 							    beg_run, run_length, task_tag);
4100 		}
4101 		task = get_scsi_task_from_itt(conn, task_tag, ISCSI_OP_R2T);
4102 		if (task) {
4103 			return iscsi_handle_r2t_snack(conn, task, pdu, beg_run,
4104 						      run_length, task_tag);
4105 		}
4106 		SPDK_ERRLOG("It is Neither datain nor r2t recovery request\n");
4107 		rc = -1;
4108 		break;
4109 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
4110 		rc = iscsi_handle_status_snack(conn, pdu);
4111 		break;
4112 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
4113 		rc = iscsi_handle_data_ack(conn, pdu);
4114 		break;
4115 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
4116 		SPDK_ERRLOG("R-Data SNACK is Not Supported int spdk\n");
4117 		rc = iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4118 		break;
4119 	default:
4120 		SPDK_ERRLOG("Unknown SNACK type %d, protocol error\n", type);
4121 		rc = iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4122 		break;
4123 	}
4124 
4125 	return rc;
4126 }
4127 
4128 static int
4129 iscsi_pdu_hdr_op_data(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4130 {
4131 	struct spdk_iscsi_task	*task, *subtask;
4132 	struct iscsi_bhs_data_out *reqh;
4133 	struct spdk_scsi_lun	*lun_dev;
4134 	uint32_t transfer_tag;
4135 	uint32_t task_tag;
4136 	uint32_t transfer_len;
4137 	uint32_t DataSN;
4138 	uint32_t buffer_offset;
4139 	uint32_t len;
4140 	int F_bit;
4141 	int rc;
4142 	int reject_reason = ISCSI_REASON_INVALID_PDU_FIELD;
4143 
4144 	if (conn->sess->session_type == SESSION_TYPE_DISCOVERY) {
4145 		SPDK_ERRLOG("ISCSI_OP_SCSI_DATAOUT not allowed in discovery session\n");
4146 		return SPDK_ISCSI_CONNECTION_FATAL;
4147 	}
4148 
4149 	reqh = (struct iscsi_bhs_data_out *)&pdu->bhs;
4150 	F_bit = !!(reqh->flags & ISCSI_FLAG_FINAL);
4151 	transfer_tag = from_be32(&reqh->ttt);
4152 	task_tag = from_be32(&reqh->itt);
4153 	DataSN = from_be32(&reqh->data_sn);
4154 	buffer_offset = from_be32(&reqh->buffer_offset);
4155 
4156 	if (pdu->data_segment_len > SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH) {
4157 		reject_reason = ISCSI_REASON_PROTOCOL_ERROR;
4158 		goto reject_return;
4159 	}
4160 
4161 	task = get_transfer_task(conn, transfer_tag);
4162 	if (task == NULL) {
4163 		SPDK_ERRLOG("Not found task for transfer_tag=%x\n", transfer_tag);
4164 		goto reject_return;
4165 	}
4166 
4167 	lun_dev = spdk_scsi_dev_get_lun(conn->dev, task->lun_id);
4168 
4169 	if (pdu->data_segment_len > task->desired_data_transfer_length) {
4170 		SPDK_ERRLOG("the dataout pdu data length is larger than the value sent by R2T PDU\n");
4171 		return SPDK_ISCSI_CONNECTION_FATAL;
4172 	}
4173 
4174 	if (task->tag != task_tag) {
4175 		SPDK_ERRLOG("The r2t task tag is %u, and the dataout task tag is %u\n",
4176 			    task->tag, task_tag);
4177 		goto reject_return;
4178 	}
4179 
4180 	if (DataSN != task->r2t_datasn) {
4181 		SPDK_ERRLOG("DataSN(%u) exp=%d error\n", DataSN, task->r2t_datasn);
4182 		if (conn->sess->ErrorRecoveryLevel >= 1) {
4183 			goto send_r2t_recovery_return;
4184 		} else {
4185 			reject_reason = ISCSI_REASON_PROTOCOL_ERROR;
4186 			goto reject_return;
4187 		}
4188 	}
4189 
4190 	if (buffer_offset != task->next_expected_r2t_offset) {
4191 		SPDK_ERRLOG("offset(%u) error\n", buffer_offset);
4192 		return SPDK_ISCSI_CONNECTION_FATAL;
4193 	}
4194 
4195 	transfer_len = task->scsi.transfer_len;
4196 	task->current_r2t_length += pdu->data_segment_len;
4197 	task->next_expected_r2t_offset += pdu->data_segment_len;
4198 	task->r2t_datasn++;
4199 
4200 	if (task->current_r2t_length > conn->sess->MaxBurstLength) {
4201 		SPDK_ERRLOG("R2T burst(%u) > MaxBurstLength(%u)\n",
4202 			    task->current_r2t_length,
4203 			    conn->sess->MaxBurstLength);
4204 		return SPDK_ISCSI_CONNECTION_FATAL;
4205 	}
4206 
4207 	if (F_bit) {
4208 		/*
4209 		 * This R2T burst is done. Clear the length before we
4210 		 *  receive a PDU for the next R2t burst.
4211 		 */
4212 		task->current_r2t_length = 0;
4213 	}
4214 
4215 	subtask = iscsi_task_get(conn, task, iscsi_task_cpl);
4216 	if (subtask == NULL) {
4217 		SPDK_ERRLOG("Unable to acquire subtask\n");
4218 		return SPDK_ISCSI_CONNECTION_FATAL;
4219 	}
4220 	subtask->scsi.offset = buffer_offset;
4221 	subtask->scsi.length = pdu->data_segment_len;
4222 	iscsi_task_associate_pdu(subtask, pdu);
4223 
4224 	if (task->next_expected_r2t_offset == transfer_len) {
4225 		task->acked_r2tsn++;
4226 	} else if (F_bit && (task->next_r2t_offset < transfer_len)) {
4227 		task->acked_r2tsn++;
4228 		len = spdk_min(conn->sess->MaxBurstLength,
4229 			       (transfer_len - task->next_r2t_offset));
4230 		rc = iscsi_send_r2t(conn, task, task->next_r2t_offset, len,
4231 				    task->ttt, &task->R2TSN);
4232 		if (rc < 0) {
4233 			SPDK_ERRLOG("iscsi_send_r2t() failed\n");
4234 		}
4235 		task->next_r2t_offset += len;
4236 	}
4237 
4238 	if (lun_dev == NULL) {
4239 		SPDK_DEBUGLOG(iscsi, "LUN %d is removed, complete the task immediately\n",
4240 			      task->lun_id);
4241 		subtask->scsi.transfer_len = subtask->scsi.length;
4242 		spdk_scsi_task_process_null_lun(&subtask->scsi);
4243 		iscsi_task_cpl(&subtask->scsi);
4244 		return 0;
4245 	}
4246 
4247 	if (spdk_unlikely(spdk_scsi_lun_get_dif_ctx(lun_dev, &subtask->scsi, &pdu->dif_ctx))) {
4248 		pdu->dif_insert_or_strip = true;
4249 	}
4250 
4251 	pdu->task = subtask;
4252 	return 0;
4253 
4254 send_r2t_recovery_return:
4255 	rc = iscsi_send_r2t_recovery(conn, task, task->acked_r2tsn, true);
4256 	if (rc == 0) {
4257 		return 0;
4258 	}
4259 
4260 reject_return:
4261 	return iscsi_reject(conn, pdu, reject_reason);
4262 }
4263 
4264 static int
4265 iscsi_pdu_payload_op_data(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4266 {
4267 	struct spdk_iscsi_task *subtask;
4268 	struct iscsi_bhs_data_out *reqh;
4269 	uint32_t transfer_tag;
4270 
4271 	if (pdu->task == NULL) {
4272 		return 0;
4273 	}
4274 
4275 	subtask = pdu->task;
4276 
4277 	reqh = (struct iscsi_bhs_data_out *)&pdu->bhs;
4278 	transfer_tag = from_be32(&reqh->ttt);
4279 
4280 	if (get_transfer_task(conn, transfer_tag) == NULL) {
4281 		SPDK_ERRLOG("Not found for transfer_tag=%x\n", transfer_tag);
4282 		subtask->scsi.transfer_len = subtask->scsi.length;
4283 		spdk_scsi_task_process_abort(&subtask->scsi);
4284 		iscsi_task_cpl(&subtask->scsi);
4285 		return 0;
4286 	}
4287 
4288 	if (spdk_likely(!pdu->dif_insert_or_strip)) {
4289 		spdk_scsi_task_set_data(&subtask->scsi, pdu->data, pdu->data_segment_len);
4290 	} else {
4291 		spdk_scsi_task_set_data(&subtask->scsi, pdu->data, pdu->data_buf_len);
4292 	}
4293 
4294 	if (spdk_scsi_dev_get_lun(conn->dev, subtask->lun_id) == NULL) {
4295 		SPDK_DEBUGLOG(iscsi, "LUN %d is removed, complete the task immediately\n",
4296 			      subtask->lun_id);
4297 		subtask->scsi.transfer_len = subtask->scsi.length;
4298 		spdk_scsi_task_process_null_lun(&subtask->scsi);
4299 		iscsi_task_cpl(&subtask->scsi);
4300 		return 0;
4301 	}
4302 
4303 	iscsi_queue_task(conn, subtask);
4304 	return 0;
4305 }
4306 
4307 static void
4308 init_login_reject_response(struct spdk_iscsi_pdu *pdu, struct spdk_iscsi_pdu *rsp_pdu)
4309 {
4310 	struct iscsi_bhs_login_rsp *rsph;
4311 
4312 	memset(rsp_pdu, 0, sizeof(struct spdk_iscsi_pdu));
4313 	rsph = (struct iscsi_bhs_login_rsp *)&rsp_pdu->bhs;
4314 	rsph->version_max = ISCSI_VERSION;
4315 	rsph->version_act = ISCSI_VERSION;
4316 	rsph->opcode = ISCSI_OP_LOGIN_RSP;
4317 	rsph->status_class = ISCSI_CLASS_INITIATOR_ERROR;
4318 	rsph->status_detail = ISCSI_LOGIN_INVALID_LOGIN_REQUEST;
4319 	rsph->itt = pdu->bhs.itt;
4320 }
4321 
4322 static void
4323 iscsi_pdu_dump(struct spdk_iscsi_pdu *pdu)
4324 {
4325 	spdk_log_dump(stderr, "PDU", (uint8_t *)&pdu->bhs, ISCSI_BHS_LEN);
4326 }
4327 
4328 /* This function is used to refree the pdu when it is acknowledged */
4329 static void
4330 remove_acked_pdu(struct spdk_iscsi_conn *conn, uint32_t ExpStatSN)
4331 {
4332 	struct spdk_iscsi_pdu *pdu, *pdu_temp;
4333 	uint32_t stat_sn;
4334 
4335 	conn->exp_statsn = spdk_min(ExpStatSN, conn->StatSN);
4336 	TAILQ_FOREACH_SAFE(pdu, &conn->snack_pdu_list, tailq, pdu_temp) {
4337 		stat_sn = from_be32(&pdu->bhs.stat_sn);
4338 		if (spdk_sn32_lt(stat_sn, conn->exp_statsn)) {
4339 			TAILQ_REMOVE(&conn->snack_pdu_list, pdu, tailq);
4340 			iscsi_conn_free_pdu(conn, pdu);
4341 		}
4342 	}
4343 }
4344 
4345 static int
4346 iscsi_update_cmdsn(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4347 {
4348 	int opcode;
4349 	uint32_t ExpStatSN;
4350 	int I_bit;
4351 	struct spdk_iscsi_sess *sess;
4352 	struct iscsi_bhs_scsi_req *reqh;
4353 
4354 	sess = conn->sess;
4355 	if (!sess) {
4356 		SPDK_ERRLOG("Connection has no associated session!\n");
4357 		return SPDK_ISCSI_CONNECTION_FATAL;
4358 	}
4359 
4360 	opcode = pdu->bhs.opcode;
4361 	reqh = (struct iscsi_bhs_scsi_req *)&pdu->bhs;
4362 
4363 	pdu->cmd_sn = from_be32(&reqh->cmd_sn);
4364 
4365 	I_bit = reqh->immediate;
4366 	if (I_bit == 0) {
4367 		if (spdk_sn32_lt(pdu->cmd_sn, sess->ExpCmdSN) ||
4368 		    spdk_sn32_gt(pdu->cmd_sn, sess->MaxCmdSN)) {
4369 			if (sess->session_type == SESSION_TYPE_NORMAL &&
4370 			    opcode != ISCSI_OP_SCSI_DATAOUT) {
4371 				SPDK_ERRLOG("CmdSN(%u) ignore (ExpCmdSN=%u, MaxCmdSN=%u)\n",
4372 					    pdu->cmd_sn, sess->ExpCmdSN, sess->MaxCmdSN);
4373 
4374 				if (sess->ErrorRecoveryLevel >= 1) {
4375 					SPDK_DEBUGLOG(iscsi, "Skip the error in ERL 1 and 2\n");
4376 				} else {
4377 					return SPDK_PDU_FATAL;
4378 				}
4379 			}
4380 		}
4381 	} else if (pdu->cmd_sn != sess->ExpCmdSN) {
4382 		SPDK_ERRLOG("CmdSN(%u) error ExpCmdSN=%u\n", pdu->cmd_sn, sess->ExpCmdSN);
4383 
4384 		if (sess->ErrorRecoveryLevel >= 1) {
4385 			SPDK_DEBUGLOG(iscsi, "Skip the error in ERL 1 and 2\n");
4386 		} else if (opcode != ISCSI_OP_NOPOUT) {
4387 			/*
4388 			 * The Linux initiator does not send valid CmdSNs for
4389 			 *  nopout under heavy load, so do not close the
4390 			 *  connection in that case.
4391 			 */
4392 			return SPDK_ISCSI_CONNECTION_FATAL;
4393 		}
4394 	}
4395 
4396 	ExpStatSN = from_be32(&reqh->exp_stat_sn);
4397 	if (spdk_sn32_gt(ExpStatSN, conn->StatSN)) {
4398 		SPDK_DEBUGLOG(iscsi, "StatSN(%u) advanced\n", ExpStatSN);
4399 		ExpStatSN = conn->StatSN;
4400 	}
4401 
4402 	if (sess->ErrorRecoveryLevel >= 1) {
4403 		remove_acked_pdu(conn, ExpStatSN);
4404 	}
4405 
4406 	if (!I_bit && opcode != ISCSI_OP_SCSI_DATAOUT) {
4407 		sess->ExpCmdSN++;
4408 	}
4409 
4410 	return 0;
4411 }
4412 
4413 static int
4414 iscsi_pdu_hdr_handle(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4415 {
4416 	int opcode;
4417 	int rc;
4418 	struct spdk_iscsi_pdu *rsp_pdu = NULL;
4419 
4420 	if (pdu == NULL) {
4421 		return -1;
4422 	}
4423 
4424 	opcode = pdu->bhs.opcode;
4425 
4426 	SPDK_DEBUGLOG(iscsi, "opcode %x\n", opcode);
4427 
4428 	if (opcode == ISCSI_OP_LOGIN) {
4429 		return iscsi_pdu_hdr_op_login(conn, pdu);
4430 	}
4431 
4432 	/* connection in login phase but receive non-login opcode
4433 	 * return response code 0x020b to initiator.
4434 	 * */
4435 	if (!conn->full_feature && conn->state == ISCSI_CONN_STATE_RUNNING) {
4436 		rsp_pdu = iscsi_get_pdu(conn);
4437 		if (rsp_pdu == NULL) {
4438 			return SPDK_ISCSI_CONNECTION_FATAL;
4439 		}
4440 		init_login_reject_response(pdu, rsp_pdu);
4441 		iscsi_conn_write_pdu(conn, rsp_pdu, iscsi_conn_pdu_generic_complete, NULL);
4442 		SPDK_ERRLOG("Received opcode %d in login phase\n", opcode);
4443 		return SPDK_ISCSI_LOGIN_ERROR_RESPONSE;
4444 	} else if (conn->state == ISCSI_CONN_STATE_INVALID) {
4445 		SPDK_ERRLOG("before Full Feature\n");
4446 		iscsi_pdu_dump(pdu);
4447 		return SPDK_ISCSI_CONNECTION_FATAL;
4448 	}
4449 
4450 	rc = iscsi_update_cmdsn(conn, pdu);
4451 	if (rc != 0) {
4452 		return rc;
4453 	}
4454 
4455 	switch (opcode) {
4456 	case ISCSI_OP_NOPOUT:
4457 		rc = iscsi_pdu_hdr_op_nopout(conn, pdu);
4458 		break;
4459 
4460 	case ISCSI_OP_SCSI:
4461 		rc = iscsi_pdu_hdr_op_scsi(conn, pdu);
4462 		break;
4463 	case ISCSI_OP_TASK:
4464 		rc = iscsi_pdu_hdr_op_task(conn, pdu);
4465 		break;
4466 
4467 	case ISCSI_OP_TEXT:
4468 		rc = iscsi_pdu_hdr_op_text(conn, pdu);
4469 		break;
4470 
4471 	case ISCSI_OP_LOGOUT:
4472 		rc = iscsi_pdu_hdr_op_logout(conn, pdu);
4473 		break;
4474 
4475 	case ISCSI_OP_SCSI_DATAOUT:
4476 		rc = iscsi_pdu_hdr_op_data(conn, pdu);
4477 		break;
4478 
4479 	case ISCSI_OP_SNACK:
4480 		rc = iscsi_pdu_hdr_op_snack(conn, pdu);
4481 		break;
4482 
4483 	default:
4484 		SPDK_ERRLOG("unsupported opcode %x\n", opcode);
4485 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4486 	}
4487 
4488 	if (rc < 0) {
4489 		SPDK_ERRLOG("processing PDU header (opcode=%x) failed on %s(%s)\n",
4490 			    opcode,
4491 			    conn->target_port != NULL ? spdk_scsi_port_get_name(conn->target_port) : "NULL",
4492 			    conn->initiator_port != NULL ? spdk_scsi_port_get_name(conn->initiator_port) : "NULL");
4493 	}
4494 
4495 	return rc;
4496 }
4497 
4498 static int
4499 iscsi_pdu_payload_handle(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)
4500 {
4501 	int opcode;
4502 	int rc = 0;
4503 
4504 	opcode = pdu->bhs.opcode;
4505 
4506 	SPDK_DEBUGLOG(iscsi, "opcode %x\n", opcode);
4507 
4508 	switch (opcode) {
4509 	case ISCSI_OP_LOGIN:
4510 		rc = iscsi_pdu_payload_op_login(conn, pdu);
4511 		break;
4512 	case ISCSI_OP_NOPOUT:
4513 		rc = iscsi_pdu_payload_op_nopout(conn, pdu);
4514 		break;
4515 	case ISCSI_OP_SCSI:
4516 		rc = iscsi_pdu_payload_op_scsi(conn, pdu);
4517 		break;
4518 	case ISCSI_OP_TASK:
4519 		break;
4520 	case ISCSI_OP_TEXT:
4521 		rc = iscsi_pdu_payload_op_text(conn, pdu);
4522 		break;
4523 	case ISCSI_OP_LOGOUT:
4524 		break;
4525 	case ISCSI_OP_SCSI_DATAOUT:
4526 		rc = iscsi_pdu_payload_op_data(conn, pdu);
4527 		break;
4528 	case ISCSI_OP_SNACK:
4529 		break;
4530 	default:
4531 		SPDK_ERRLOG("unsupported opcode %x\n", opcode);
4532 		return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);
4533 	}
4534 
4535 	if (rc < 0) {
4536 		SPDK_ERRLOG("processing PDU payload (opcode=%x) failed on %s(%s)\n",
4537 			    opcode,
4538 			    conn->target_port != NULL ? spdk_scsi_port_get_name(conn->target_port) : "NULL",
4539 			    conn->initiator_port != NULL ? spdk_scsi_port_get_name(conn->initiator_port) : "NULL");
4540 	}
4541 
4542 	return rc;
4543 }
4544 
4545 static int
4546 iscsi_read_pdu(struct spdk_iscsi_conn *conn)
4547 {
4548 	enum iscsi_pdu_recv_state prev_state;
4549 	struct spdk_iscsi_pdu *pdu;
4550 	struct spdk_mempool *pool;
4551 	uint32_t crc32c;
4552 	int ahs_len;
4553 	uint32_t data_len;
4554 	int rc;
4555 
4556 	do {
4557 		prev_state = conn->pdu_recv_state;
4558 		pdu = conn->pdu_in_progress;
4559 
4560 		switch (conn->pdu_recv_state) {
4561 		case ISCSI_PDU_RECV_STATE_AWAIT_PDU_READY:
4562 			assert(conn->pdu_in_progress == NULL);
4563 
4564 			conn->pdu_in_progress = iscsi_get_pdu(conn);
4565 			if (conn->pdu_in_progress == NULL) {
4566 				return SPDK_ISCSI_CONNECTION_FATAL;
4567 			}
4568 			conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_AWAIT_PDU_HDR;
4569 			break;
4570 		case ISCSI_PDU_RECV_STATE_AWAIT_PDU_HDR:
4571 			if (pdu->bhs_valid_bytes < ISCSI_BHS_LEN) {
4572 				rc = iscsi_conn_read_data(conn,
4573 							  ISCSI_BHS_LEN - pdu->bhs_valid_bytes,
4574 							  (uint8_t *)&pdu->bhs + pdu->bhs_valid_bytes);
4575 				if (rc < 0) {
4576 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4577 					break;
4578 				}
4579 				pdu->bhs_valid_bytes += rc;
4580 				if (pdu->bhs_valid_bytes < ISCSI_BHS_LEN) {
4581 					return 0;
4582 				}
4583 			}
4584 
4585 			/* conn->is_logged_out must be checked after completing to process
4586 			 * logout request, i.e., before processing PDU header in this state
4587 			 * machine, otherwise logout response may not be sent to initiator
4588 			 * and initiator may get logout timeout.
4589 			 */
4590 			if (spdk_unlikely(conn->is_logged_out)) {
4591 				SPDK_DEBUGLOG(iscsi, "pdu received after logout\n");
4592 				conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4593 				break;
4594 			}
4595 
4596 			pdu->data_segment_len = ISCSI_ALIGN(DGET24(pdu->bhs.data_segment_len));
4597 
4598 			/* AHS */
4599 			ahs_len = pdu->bhs.total_ahs_len * 4;
4600 			if (ahs_len > ISCSI_AHS_LEN) {
4601 				SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "pdu ahs length %d is invalid\n", ahs_len);
4602 				conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4603 				break;
4604 			}
4605 
4606 			if (pdu->ahs_valid_bytes < ahs_len) {
4607 				rc = iscsi_conn_read_data(conn,
4608 							  ahs_len - pdu->ahs_valid_bytes,
4609 							  pdu->ahs + pdu->ahs_valid_bytes);
4610 				if (rc < 0) {
4611 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4612 					break;
4613 				}
4614 
4615 				pdu->ahs_valid_bytes += rc;
4616 				if (pdu->ahs_valid_bytes < ahs_len) {
4617 					return 0;
4618 				}
4619 			}
4620 
4621 			/* Header Digest */
4622 			if (conn->header_digest &&
4623 			    pdu->hdigest_valid_bytes < ISCSI_DIGEST_LEN) {
4624 				rc = iscsi_conn_read_data(conn,
4625 							  ISCSI_DIGEST_LEN - pdu->hdigest_valid_bytes,
4626 							  pdu->header_digest + pdu->hdigest_valid_bytes);
4627 				if (rc < 0) {
4628 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4629 					break;
4630 				}
4631 
4632 				pdu->hdigest_valid_bytes += rc;
4633 				if (pdu->hdigest_valid_bytes < ISCSI_DIGEST_LEN) {
4634 					return 0;
4635 				}
4636 			}
4637 
4638 			if (conn->header_digest) {
4639 				crc32c = iscsi_pdu_calc_header_digest(pdu);
4640 				rc = MATCH_DIGEST_WORD(pdu->header_digest, crc32c);
4641 				if (rc == 0) {
4642 					SPDK_ERRLOG("header digest error (%s)\n", conn->initiator_name);
4643 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4644 					break;
4645 				}
4646 			}
4647 
4648 			rc = iscsi_pdu_hdr_handle(conn, pdu);
4649 			if (rc < 0) {
4650 				SPDK_ERRLOG("Critical error is detected. Close the connection\n");
4651 				conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4652 				break;
4653 			}
4654 
4655 			conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_AWAIT_PDU_PAYLOAD;
4656 			break;
4657 		case ISCSI_PDU_RECV_STATE_AWAIT_PDU_PAYLOAD:
4658 			data_len = pdu->data_segment_len;
4659 
4660 			if (data_len != 0 && pdu->data_buf == NULL) {
4661 				if (data_len <= iscsi_get_max_immediate_data_size()) {
4662 					pool = g_iscsi.pdu_immediate_data_pool;
4663 					pdu->data_buf_len = SPDK_BDEV_BUF_SIZE_WITH_MD(iscsi_get_max_immediate_data_size());
4664 				} else if (data_len <= SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH) {
4665 					pool = g_iscsi.pdu_data_out_pool;
4666 					pdu->data_buf_len = SPDK_BDEV_BUF_SIZE_WITH_MD(SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH);
4667 				} else {
4668 					SPDK_ERRLOG("Data(%d) > MaxSegment(%d)\n",
4669 						    data_len, SPDK_ISCSI_MAX_RECV_DATA_SEGMENT_LENGTH);
4670 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4671 					break;
4672 				}
4673 				pdu->mobj = spdk_mempool_get(pool);
4674 				if (pdu->mobj == NULL) {
4675 					return 0;
4676 				}
4677 				pdu->data_buf = pdu->mobj->buf;
4678 				pdu->data = pdu->mobj->buf;
4679 				pdu->data_from_mempool = true;
4680 			}
4681 
4682 			/* copy the actual data into local buffer */
4683 			if (pdu->data_valid_bytes < data_len) {
4684 				rc = iscsi_conn_read_data_segment(conn, pdu, data_len);
4685 				if (rc < 0) {
4686 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4687 					break;
4688 				}
4689 
4690 				pdu->data_valid_bytes += rc;
4691 				if (pdu->data_valid_bytes < data_len) {
4692 					return 0;
4693 				}
4694 			}
4695 
4696 			/* copy out the data digest */
4697 			if (conn->data_digest && data_len != 0 &&
4698 			    pdu->ddigest_valid_bytes < ISCSI_DIGEST_LEN) {
4699 				rc = iscsi_conn_read_data(conn,
4700 							  ISCSI_DIGEST_LEN - pdu->ddigest_valid_bytes,
4701 							  pdu->data_digest + pdu->ddigest_valid_bytes);
4702 				if (rc < 0) {
4703 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4704 					break;
4705 				}
4706 
4707 				pdu->ddigest_valid_bytes += rc;
4708 				if (pdu->ddigest_valid_bytes < ISCSI_DIGEST_LEN) {
4709 					return 0;
4710 				}
4711 			}
4712 
4713 			/* All data for this PDU has now been read from the socket. */
4714 			spdk_trace_record(TRACE_ISCSI_READ_PDU, conn->id, pdu->data_valid_bytes,
4715 					  (uintptr_t)pdu, pdu->bhs.opcode);
4716 
4717 			/* check data digest */
4718 			if (conn->data_digest && data_len != 0) {
4719 				crc32c = iscsi_pdu_calc_data_digest(pdu);
4720 				rc = MATCH_DIGEST_WORD(pdu->data_digest, crc32c);
4721 				if (rc == 0) {
4722 					SPDK_ERRLOG("data digest error (%s)\n", conn->initiator_name);
4723 					conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4724 					break;
4725 				}
4726 			}
4727 
4728 			if (!pdu->is_rejected) {
4729 				rc = iscsi_pdu_payload_handle(conn, pdu);
4730 			} else {
4731 				rc = 0;
4732 			}
4733 			if (rc == 0) {
4734 				spdk_trace_record(TRACE_ISCSI_TASK_EXECUTED, 0, 0, (uintptr_t)pdu, 0);
4735 				iscsi_put_pdu(pdu);
4736 				conn->pdu_in_progress = NULL;
4737 				conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_AWAIT_PDU_READY;
4738 				return 1;
4739 			} else {
4740 				conn->pdu_recv_state = ISCSI_PDU_RECV_STATE_ERROR;
4741 			}
4742 			break;
4743 		case ISCSI_PDU_RECV_STATE_ERROR:
4744 			return SPDK_ISCSI_CONNECTION_FATAL;
4745 		default:
4746 			assert(false);
4747 			SPDK_ERRLOG("code should not come here\n");
4748 			break;
4749 		}
4750 	} while (prev_state != conn->pdu_recv_state);
4751 
4752 	return 0;
4753 }
4754 
4755 #define GET_PDU_LOOP_COUNT	16
4756 
4757 int
4758 iscsi_handle_incoming_pdus(struct spdk_iscsi_conn *conn)
4759 {
4760 	int i, rc;
4761 
4762 	/* Read new PDUs from network */
4763 	for (i = 0; i < GET_PDU_LOOP_COUNT; i++) {
4764 		rc = iscsi_read_pdu(conn);
4765 		if (rc == 0) {
4766 			break;
4767 		} else if (rc < 0) {
4768 			return rc;
4769 		}
4770 
4771 		if (conn->is_stopped) {
4772 			break;
4773 		}
4774 	}
4775 
4776 	return i;
4777 }
4778