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1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * RFC 3720 (iSCSI) protocol data types
4  *
5  * Copyright (C) 2005 Dmitry Yusupov
6  * Copyright (C) 2005 Alex Aizman
7  * maintained by open-iscsi@googlegroups.com
8  */
9 
10 #ifndef ISCSI_PROTO_H
11 #define ISCSI_PROTO_H
12 
13 #include <linux/types.h>
14 #include <scsi/scsi.h>
15 
16 #define ISCSI_DRAFT20_VERSION	0x00
17 
18 /* default iSCSI listen port for incoming connections */
19 #define ISCSI_LISTEN_PORT	3260
20 
21 /* iSCSI header length */
22 #define ISCSI_HDR_LEN		48
23 
24 /* iSCSI CRC32C length */
25 #define ISCSI_CRC_LEN		4
26 
27 /* Padding word length */
28 #define ISCSI_PAD_LEN		4
29 
30 /*
31  * Serial Number Arithmetic, 32 bits, RFC1982
32  */
33 
iscsi_sna_lt(u32 n1,u32 n2)34 static inline int iscsi_sna_lt(u32 n1, u32 n2)
35 {
36 	return (s32)(n1 - n2) < 0;
37 }
38 
iscsi_sna_lte(u32 n1,u32 n2)39 static inline int iscsi_sna_lte(u32 n1, u32 n2)
40 {
41 	return (s32)(n1 - n2) <= 0;
42 }
43 
iscsi_sna_gt(u32 n1,u32 n2)44 static inline int iscsi_sna_gt(u32 n1, u32 n2)
45 {
46 	return (s32)(n1 - n2) > 0;
47 }
48 
iscsi_sna_gte(u32 n1,u32 n2)49 static inline int iscsi_sna_gte(u32 n1, u32 n2)
50 {
51 	return (s32)(n1 - n2) >= 0;
52 }
53 
54 /*
55  * useful common(control and data paths) macro
56  */
57 #define ntoh24(p) (((p)[0] << 16) | ((p)[1] << 8) | ((p)[2]))
58 #define hton24(p, v) { \
59         p[0] = (((v) >> 16) & 0xFF); \
60         p[1] = (((v) >> 8) & 0xFF); \
61         p[2] = ((v) & 0xFF); \
62 }
63 #define zero_data(p) {p[0]=0;p[1]=0;p[2]=0;}
64 
65 /* initiator tags; opaque for target */
66 typedef uint32_t __bitwise itt_t;
67 /* below makes sense only for initiator that created this tag */
68 #define build_itt(itt, age) ((__force itt_t)\
69 	((itt) | ((age) << ISCSI_AGE_SHIFT)))
70 #define get_itt(itt) ((__force uint32_t)(itt_t)(itt) & ISCSI_ITT_MASK)
71 #define RESERVED_ITT ((__force itt_t)0xffffffff)
72 
73 /*
74  * iSCSI Template Message Header
75  */
76 struct iscsi_hdr {
77 	uint8_t		opcode;
78 	uint8_t		flags;		/* Final bit */
79 	uint8_t		rsvd2[2];
80 	uint8_t		hlength;	/* AHSs total length */
81 	uint8_t		dlength[3];	/* Data length */
82 	struct scsi_lun	lun;
83 	itt_t		itt;		/* Initiator Task Tag, opaque for target */
84 	__be32		ttt;		/* Target Task Tag */
85 	__be32		statsn;
86 	__be32		exp_statsn;
87 	__be32		max_statsn;
88 	uint8_t		other[12];
89 };
90 
91 /************************* RFC 3720 Begin *****************************/
92 
93 #define ISCSI_RESERVED_TAG		0xffffffff
94 
95 /* Opcode encoding bits */
96 #define ISCSI_OP_RETRY			0x80
97 #define ISCSI_OP_IMMEDIATE		0x40
98 #define ISCSI_OPCODE_MASK		0x3F
99 
100 /* Initiator Opcode values */
101 #define ISCSI_OP_NOOP_OUT		0x00
102 #define ISCSI_OP_SCSI_CMD		0x01
103 #define ISCSI_OP_SCSI_TMFUNC		0x02
104 #define ISCSI_OP_LOGIN			0x03
105 #define ISCSI_OP_TEXT			0x04
106 #define ISCSI_OP_SCSI_DATA_OUT		0x05
107 #define ISCSI_OP_LOGOUT			0x06
108 #define ISCSI_OP_SNACK			0x10
109 
110 #define ISCSI_OP_VENDOR1_CMD		0x1c
111 #define ISCSI_OP_VENDOR2_CMD		0x1d
112 #define ISCSI_OP_VENDOR3_CMD		0x1e
113 #define ISCSI_OP_VENDOR4_CMD		0x1f
114 
115 /* Target Opcode values */
116 #define ISCSI_OP_NOOP_IN		0x20
117 #define ISCSI_OP_SCSI_CMD_RSP		0x21
118 #define ISCSI_OP_SCSI_TMFUNC_RSP	0x22
119 #define ISCSI_OP_LOGIN_RSP		0x23
120 #define ISCSI_OP_TEXT_RSP		0x24
121 #define ISCSI_OP_SCSI_DATA_IN		0x25
122 #define ISCSI_OP_LOGOUT_RSP		0x26
123 #define ISCSI_OP_R2T			0x31
124 #define ISCSI_OP_ASYNC_EVENT		0x32
125 #define ISCSI_OP_REJECT			0x3f
126 
127 struct iscsi_ahs_hdr {
128 	__be16 ahslength;
129 	uint8_t ahstype;
130 	uint8_t ahspec[5];
131 };
132 
133 #define ISCSI_AHSTYPE_CDB		1
134 #define ISCSI_AHSTYPE_RLENGTH		2
135 #define ISCSI_CDB_SIZE			16
136 
137 /* iSCSI PDU Header */
138 struct iscsi_scsi_req {
139 	uint8_t opcode;
140 	uint8_t flags;
141 	__be16 rsvd2;
142 	uint8_t hlength;
143 	uint8_t dlength[3];
144 	struct scsi_lun lun;
145 	itt_t	 itt;	/* Initiator Task Tag */
146 	__be32 data_length;
147 	__be32 cmdsn;
148 	__be32 exp_statsn;
149 	uint8_t cdb[ISCSI_CDB_SIZE];	/* SCSI Command Block */
150 	/* Additional Data (Command Dependent) */
151 };
152 
153 /* Command PDU flags */
154 #define ISCSI_FLAG_CMD_FINAL		0x80
155 #define ISCSI_FLAG_CMD_READ		0x40
156 #define ISCSI_FLAG_CMD_WRITE		0x20
157 #define ISCSI_FLAG_CMD_ATTR_MASK	0x07	/* 3 bits */
158 
159 /* SCSI Command Attribute values */
160 #define ISCSI_ATTR_UNTAGGED		0
161 #define ISCSI_ATTR_SIMPLE		1
162 #define ISCSI_ATTR_ORDERED		2
163 #define ISCSI_ATTR_HEAD_OF_QUEUE	3
164 #define ISCSI_ATTR_ACA			4
165 
166 struct iscsi_rlength_ahdr {
167 	__be16 ahslength;
168 	uint8_t ahstype;
169 	uint8_t reserved;
170 	__be32 read_length;
171 };
172 
173 /* Extended CDB AHS */
174 struct iscsi_ecdb_ahdr {
175 	__be16 ahslength;	/* CDB length - 15, including reserved byte */
176 	uint8_t ahstype;
177 	uint8_t reserved;
178 	/* 4-byte aligned extended CDB spillover */
179 	uint8_t ecdb[SCSI_MAX_VARLEN_CDB_SIZE - ISCSI_CDB_SIZE];
180 };
181 
182 /* SCSI Response Header */
183 struct iscsi_scsi_rsp {
184 	uint8_t opcode;
185 	uint8_t flags;
186 	uint8_t response;
187 	uint8_t cmd_status;
188 	uint8_t hlength;
189 	uint8_t dlength[3];
190 	uint8_t rsvd[8];
191 	itt_t	 itt;	/* Initiator Task Tag */
192 	__be32	rsvd1;
193 	__be32	statsn;
194 	__be32	exp_cmdsn;
195 	__be32	max_cmdsn;
196 	__be32	exp_datasn;
197 	__be32	bi_residual_count;
198 	__be32	residual_count;
199 	/* Response or Sense Data (optional) */
200 };
201 
202 /* Command Response PDU flags */
203 #define ISCSI_FLAG_CMD_BIDI_OVERFLOW	0x10
204 #define ISCSI_FLAG_CMD_BIDI_UNDERFLOW	0x08
205 #define ISCSI_FLAG_CMD_OVERFLOW		0x04
206 #define ISCSI_FLAG_CMD_UNDERFLOW	0x02
207 
208 /* iSCSI Status values. Valid if Rsp Selector bit is not set */
209 #define ISCSI_STATUS_CMD_COMPLETED	0
210 #define ISCSI_STATUS_TARGET_FAILURE	1
211 #define ISCSI_STATUS_SUBSYS_FAILURE	2
212 
213 /* Asynchronous Event Header */
214 struct iscsi_async {
215 	uint8_t opcode;
216 	uint8_t flags;
217 	uint8_t rsvd2[2];
218 	uint8_t rsvd3;
219 	uint8_t dlength[3];
220 	struct scsi_lun	lun;
221 	uint8_t rsvd4[8];
222 	__be32	statsn;
223 	__be32	exp_cmdsn;
224 	__be32	max_cmdsn;
225 	uint8_t async_event;
226 	uint8_t async_vcode;
227 	__be16	param1;
228 	__be16	param2;
229 	__be16	param3;
230 	uint8_t rsvd5[4];
231 };
232 
233 /* iSCSI Event Codes */
234 #define ISCSI_ASYNC_MSG_SCSI_EVENT			0
235 #define ISCSI_ASYNC_MSG_REQUEST_LOGOUT			1
236 #define ISCSI_ASYNC_MSG_DROPPING_CONNECTION		2
237 #define ISCSI_ASYNC_MSG_DROPPING_ALL_CONNECTIONS	3
238 #define ISCSI_ASYNC_MSG_PARAM_NEGOTIATION		4
239 #define ISCSI_ASYNC_MSG_VENDOR_SPECIFIC			255
240 
241 /* NOP-Out Message */
242 struct iscsi_nopout {
243 	uint8_t opcode;
244 	uint8_t flags;
245 	__be16	rsvd2;
246 	uint8_t rsvd3;
247 	uint8_t dlength[3];
248 	struct scsi_lun	lun;
249 	itt_t	 itt;	/* Initiator Task Tag */
250 	__be32	ttt;	/* Target Transfer Tag */
251 	__be32	cmdsn;
252 	__be32	exp_statsn;
253 	uint8_t rsvd4[16];
254 };
255 
256 /* NOP-In Message */
257 struct iscsi_nopin {
258 	uint8_t opcode;
259 	uint8_t flags;
260 	__be16	rsvd2;
261 	uint8_t rsvd3;
262 	uint8_t dlength[3];
263 	struct scsi_lun	lun;
264 	itt_t	 itt;	/* Initiator Task Tag */
265 	__be32	ttt;	/* Target Transfer Tag */
266 	__be32	statsn;
267 	__be32	exp_cmdsn;
268 	__be32	max_cmdsn;
269 	uint8_t rsvd4[12];
270 };
271 
272 /* SCSI Task Management Message Header */
273 struct iscsi_tm {
274 	uint8_t opcode;
275 	uint8_t flags;
276 	uint8_t rsvd1[2];
277 	uint8_t hlength;
278 	uint8_t dlength[3];
279 	struct scsi_lun lun;
280 	itt_t	 itt;	/* Initiator Task Tag */
281 	itt_t	 rtt;	/* Reference Task Tag */
282 	__be32	cmdsn;
283 	__be32	exp_statsn;
284 	__be32	refcmdsn;
285 	__be32	exp_datasn;
286 	uint8_t rsvd2[8];
287 };
288 
289 #define ISCSI_FLAG_TM_FUNC_MASK			0x7F
290 
291 /* Function values */
292 #define ISCSI_TM_FUNC_ABORT_TASK		1
293 #define ISCSI_TM_FUNC_ABORT_TASK_SET		2
294 #define ISCSI_TM_FUNC_CLEAR_ACA			3
295 #define ISCSI_TM_FUNC_CLEAR_TASK_SET		4
296 #define ISCSI_TM_FUNC_LOGICAL_UNIT_RESET	5
297 #define ISCSI_TM_FUNC_TARGET_WARM_RESET		6
298 #define ISCSI_TM_FUNC_TARGET_COLD_RESET		7
299 #define ISCSI_TM_FUNC_TASK_REASSIGN		8
300 
301 #define ISCSI_TM_FUNC_VALUE(hdr) ((hdr)->flags & ISCSI_FLAG_TM_FUNC_MASK)
302 
303 /* SCSI Task Management Response Header */
304 struct iscsi_tm_rsp {
305 	uint8_t opcode;
306 	uint8_t flags;
307 	uint8_t response;	/* see Response values below */
308 	uint8_t qualifier;
309 	uint8_t hlength;
310 	uint8_t dlength[3];
311 	uint8_t rsvd2[8];
312 	itt_t	 itt;	/* Initiator Task Tag */
313 	itt_t	 rtt;	/* Reference Task Tag */
314 	__be32	statsn;
315 	__be32	exp_cmdsn;
316 	__be32	max_cmdsn;
317 	uint8_t rsvd3[12];
318 };
319 
320 /* Response values */
321 #define ISCSI_TMF_RSP_COMPLETE		0x00
322 #define ISCSI_TMF_RSP_NO_TASK		0x01
323 #define ISCSI_TMF_RSP_NO_LUN		0x02
324 #define ISCSI_TMF_RSP_TASK_ALLEGIANT	0x03
325 #define ISCSI_TMF_RSP_NO_FAILOVER	0x04
326 #define ISCSI_TMF_RSP_NOT_SUPPORTED	0x05
327 #define ISCSI_TMF_RSP_AUTH_FAILED	0x06
328 #define ISCSI_TMF_RSP_REJECTED		0xff
329 
330 /* Ready To Transfer Header */
331 struct iscsi_r2t_rsp {
332 	uint8_t opcode;
333 	uint8_t flags;
334 	uint8_t rsvd2[2];
335 	uint8_t	hlength;
336 	uint8_t	dlength[3];
337 	struct scsi_lun	lun;
338 	itt_t	 itt;	/* Initiator Task Tag */
339 	__be32	ttt;	/* Target Transfer Tag */
340 	__be32	statsn;
341 	__be32	exp_cmdsn;
342 	__be32	max_cmdsn;
343 	__be32	r2tsn;
344 	__be32	data_offset;
345 	__be32	data_length;
346 };
347 
348 /* SCSI Data Hdr */
349 struct iscsi_data {
350 	uint8_t opcode;
351 	uint8_t flags;
352 	uint8_t rsvd2[2];
353 	uint8_t rsvd3;
354 	uint8_t dlength[3];
355 	struct scsi_lun lun;
356 	itt_t	 itt;
357 	__be32	ttt;
358 	__be32	rsvd4;
359 	__be32	exp_statsn;
360 	__be32	rsvd5;
361 	__be32	datasn;
362 	__be32	offset;
363 	__be32	rsvd6;
364 	/* Payload */
365 };
366 
367 /* SCSI Data Response Hdr */
368 struct iscsi_data_rsp {
369 	uint8_t opcode;
370 	uint8_t flags;
371 	uint8_t rsvd2;
372 	uint8_t cmd_status;
373 	uint8_t hlength;
374 	uint8_t dlength[3];
375 	struct scsi_lun	lun;
376 	itt_t	 itt;
377 	__be32	ttt;
378 	__be32	statsn;
379 	__be32	exp_cmdsn;
380 	__be32	max_cmdsn;
381 	__be32	datasn;
382 	__be32	offset;
383 	__be32	residual_count;
384 };
385 
386 /* Data Response PDU flags */
387 #define ISCSI_FLAG_DATA_ACK		0x40
388 #define ISCSI_FLAG_DATA_OVERFLOW	0x04
389 #define ISCSI_FLAG_DATA_UNDERFLOW	0x02
390 #define ISCSI_FLAG_DATA_STATUS		0x01
391 
392 /* Text Header */
393 struct iscsi_text {
394 	uint8_t opcode;
395 	uint8_t flags;
396 	uint8_t rsvd2[2];
397 	uint8_t hlength;
398 	uint8_t dlength[3];
399 	uint8_t rsvd4[8];
400 	itt_t	 itt;
401 	__be32	ttt;
402 	__be32	cmdsn;
403 	__be32	exp_statsn;
404 	uint8_t rsvd5[16];
405 	/* Text - key=value pairs */
406 };
407 
408 #define ISCSI_FLAG_TEXT_CONTINUE	0x40
409 
410 /* Text Response Header */
411 struct iscsi_text_rsp {
412 	uint8_t opcode;
413 	uint8_t flags;
414 	uint8_t rsvd2[2];
415 	uint8_t hlength;
416 	uint8_t dlength[3];
417 	uint8_t rsvd4[8];
418 	itt_t	 itt;
419 	__be32	ttt;
420 	__be32	statsn;
421 	__be32	exp_cmdsn;
422 	__be32	max_cmdsn;
423 	uint8_t rsvd5[12];
424 	/* Text Response - key:value pairs */
425 };
426 
427 /* Login Header */
428 struct iscsi_login_req {
429 	uint8_t opcode;
430 	uint8_t flags;
431 	uint8_t max_version;	/* Max. version supported */
432 	uint8_t min_version;	/* Min. version supported */
433 	uint8_t hlength;
434 	uint8_t dlength[3];
435 	uint8_t isid[6];	/* Initiator Session ID */
436 	__be16	tsih;	/* Target Session Handle */
437 	itt_t	 itt;	/* Initiator Task Tag */
438 	__be16	cid;
439 	__be16	rsvd3;
440 	__be32	cmdsn;
441 	__be32	exp_statsn;
442 	uint8_t rsvd5[16];
443 };
444 
445 /* Login PDU flags */
446 #define ISCSI_FLAG_LOGIN_TRANSIT		0x80
447 #define ISCSI_FLAG_LOGIN_CONTINUE		0x40
448 #define ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK	0x0C	/* 2 bits */
449 #define ISCSI_FLAG_LOGIN_CURRENT_STAGE1		0x04
450 #define ISCSI_FLAG_LOGIN_CURRENT_STAGE2		0x08
451 #define ISCSI_FLAG_LOGIN_CURRENT_STAGE3		0x0C
452 #define ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK	0x03	/* 2 bits */
453 #define ISCSI_FLAG_LOGIN_NEXT_STAGE1		0x01
454 #define ISCSI_FLAG_LOGIN_NEXT_STAGE2		0x02
455 #define ISCSI_FLAG_LOGIN_NEXT_STAGE3		0x03
456 
457 #define ISCSI_LOGIN_CURRENT_STAGE(flags) \
458 	((flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2)
459 #define ISCSI_LOGIN_NEXT_STAGE(flags) \
460 	(flags & ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK)
461 
462 /* Login Response Header */
463 struct iscsi_login_rsp {
464 	uint8_t opcode;
465 	uint8_t flags;
466 	uint8_t max_version;	/* Max. version supported */
467 	uint8_t active_version;	/* Active version */
468 	uint8_t hlength;
469 	uint8_t dlength[3];
470 	uint8_t isid[6];	/* Initiator Session ID */
471 	__be16	tsih;	/* Target Session Handle */
472 	itt_t	 itt;	/* Initiator Task Tag */
473 	__be32	rsvd3;
474 	__be32	statsn;
475 	__be32	exp_cmdsn;
476 	__be32	max_cmdsn;
477 	uint8_t status_class;	/* see Login RSP ststus classes below */
478 	uint8_t status_detail;	/* see Login RSP Status details below */
479 	uint8_t rsvd4[10];
480 };
481 
482 /* Login stage (phase) codes for CSG, NSG */
483 #define ISCSI_INITIAL_LOGIN_STAGE		-1
484 #define ISCSI_SECURITY_NEGOTIATION_STAGE	0
485 #define ISCSI_OP_PARMS_NEGOTIATION_STAGE	1
486 #define ISCSI_FULL_FEATURE_PHASE		3
487 
488 /* Login Status response classes */
489 #define ISCSI_STATUS_CLS_SUCCESS		0x00
490 #define ISCSI_STATUS_CLS_REDIRECT		0x01
491 #define ISCSI_STATUS_CLS_INITIATOR_ERR		0x02
492 #define ISCSI_STATUS_CLS_TARGET_ERR		0x03
493 
494 /* Login Status response detail codes */
495 /* Class-0 (Success) */
496 #define ISCSI_LOGIN_STATUS_ACCEPT		0x00
497 
498 /* Class-1 (Redirection) */
499 #define ISCSI_LOGIN_STATUS_TGT_MOVED_TEMP	0x01
500 #define ISCSI_LOGIN_STATUS_TGT_MOVED_PERM	0x02
501 
502 /* Class-2 (Initiator Error) */
503 #define ISCSI_LOGIN_STATUS_INIT_ERR		0x00
504 #define ISCSI_LOGIN_STATUS_AUTH_FAILED		0x01
505 #define ISCSI_LOGIN_STATUS_TGT_FORBIDDEN	0x02
506 #define ISCSI_LOGIN_STATUS_TGT_NOT_FOUND	0x03
507 #define ISCSI_LOGIN_STATUS_TGT_REMOVED		0x04
508 #define ISCSI_LOGIN_STATUS_NO_VERSION		0x05
509 #define ISCSI_LOGIN_STATUS_ISID_ERROR		0x06
510 #define ISCSI_LOGIN_STATUS_MISSING_FIELDS	0x07
511 #define ISCSI_LOGIN_STATUS_CONN_ADD_FAILED	0x08
512 #define ISCSI_LOGIN_STATUS_NO_SESSION_TYPE	0x09
513 #define ISCSI_LOGIN_STATUS_NO_SESSION		0x0a
514 #define ISCSI_LOGIN_STATUS_INVALID_REQUEST	0x0b
515 
516 /* Class-3 (Target Error) */
517 #define ISCSI_LOGIN_STATUS_TARGET_ERROR		0x00
518 #define ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE	0x01
519 #define ISCSI_LOGIN_STATUS_NO_RESOURCES		0x02
520 
521 /* Logout Header */
522 struct iscsi_logout {
523 	uint8_t opcode;
524 	uint8_t flags;
525 	uint8_t rsvd1[2];
526 	uint8_t hlength;
527 	uint8_t dlength[3];
528 	uint8_t rsvd2[8];
529 	itt_t	 itt;	/* Initiator Task Tag */
530 	__be16	cid;
531 	uint8_t rsvd3[2];
532 	__be32	cmdsn;
533 	__be32	exp_statsn;
534 	uint8_t rsvd4[16];
535 };
536 
537 /* Logout PDU flags */
538 #define ISCSI_FLAG_LOGOUT_REASON_MASK	0x7F
539 
540 /* logout reason_code values */
541 
542 #define ISCSI_LOGOUT_REASON_CLOSE_SESSION	0
543 #define ISCSI_LOGOUT_REASON_CLOSE_CONNECTION	1
544 #define ISCSI_LOGOUT_REASON_RECOVERY		2
545 #define ISCSI_LOGOUT_REASON_AEN_REQUEST		3
546 
547 /* Logout Response Header */
548 struct iscsi_logout_rsp {
549 	uint8_t opcode;
550 	uint8_t flags;
551 	uint8_t response;	/* see Logout response values below */
552 	uint8_t rsvd2;
553 	uint8_t hlength;
554 	uint8_t dlength[3];
555 	uint8_t rsvd3[8];
556 	itt_t	 itt;	/* Initiator Task Tag */
557 	__be32	rsvd4;
558 	__be32	statsn;
559 	__be32	exp_cmdsn;
560 	__be32	max_cmdsn;
561 	__be32	rsvd5;
562 	__be16	t2wait;
563 	__be16	t2retain;
564 	__be32	rsvd6;
565 };
566 
567 /* logout response status values */
568 
569 #define ISCSI_LOGOUT_SUCCESS			0
570 #define ISCSI_LOGOUT_CID_NOT_FOUND		1
571 #define ISCSI_LOGOUT_RECOVERY_UNSUPPORTED	2
572 #define ISCSI_LOGOUT_CLEANUP_FAILED		3
573 
574 /* SNACK Header */
575 struct iscsi_snack {
576 	uint8_t opcode;
577 	uint8_t flags;
578 	uint8_t rsvd2[2];
579 	uint8_t hlength;
580 	uint8_t dlength[3];
581 	uint8_t lun[8];
582 	itt_t	 itt;
583 	__be32  ttt;
584 	uint8_t rsvd3[4];
585 	__be32  exp_statsn;
586 	uint8_t rsvd4[8];
587 	__be32	begrun;
588 	__be32	runlength;
589 };
590 
591 /* SNACK PDU flags */
592 #define ISCSI_FLAG_SNACK_TYPE_DATA		0
593 #define ISCSI_FLAG_SNACK_TYPE_R2T		0
594 #define ISCSI_FLAG_SNACK_TYPE_STATUS		1
595 #define ISCSI_FLAG_SNACK_TYPE_DATA_ACK		2
596 #define ISCSI_FLAG_SNACK_TYPE_RDATA		3
597 #define ISCSI_FLAG_SNACK_TYPE_MASK	0x0F	/* 4 bits */
598 
599 /* Reject Message Header */
600 struct iscsi_reject {
601 	uint8_t opcode;
602 	uint8_t flags;
603 	uint8_t reason;
604 	uint8_t rsvd2;
605 	uint8_t hlength;
606 	uint8_t dlength[3];
607 	uint8_t rsvd3[8];
608 	__be32  ffffffff;
609 	uint8_t rsvd4[4];
610 	__be32	statsn;
611 	__be32	exp_cmdsn;
612 	__be32	max_cmdsn;
613 	__be32	datasn;
614 	uint8_t rsvd5[8];
615 	/* Text - Rejected hdr */
616 };
617 
618 /* Reason for Reject */
619 #define ISCSI_REASON_CMD_BEFORE_LOGIN	1
620 #define ISCSI_REASON_DATA_DIGEST_ERROR	2
621 #define ISCSI_REASON_DATA_SNACK_REJECT	3
622 #define ISCSI_REASON_PROTOCOL_ERROR	4
623 #define ISCSI_REASON_CMD_NOT_SUPPORTED	5
624 #define ISCSI_REASON_IMM_CMD_REJECT		6
625 #define ISCSI_REASON_TASK_IN_PROGRESS	7
626 #define ISCSI_REASON_INVALID_SNACK		8
627 #define ISCSI_REASON_BOOKMARK_INVALID	9
628 #define ISCSI_REASON_BOOKMARK_NO_RESOURCES	10
629 #define ISCSI_REASON_NEGOTIATION_RESET	11
630 
631 /* Max. number of Key=Value pairs in a text message */
632 #define MAX_KEY_VALUE_PAIRS	8192
633 
634 /* maximum length for text keys/values */
635 #define KEY_MAXLEN		64
636 #define VALUE_MAXLEN		255
637 #define TARGET_NAME_MAXLEN	VALUE_MAXLEN
638 
639 #define ISCSI_DEF_MAX_RECV_SEG_LEN		8192
640 #define ISCSI_MIN_MAX_RECV_SEG_LEN		512
641 #define ISCSI_MAX_MAX_RECV_SEG_LEN		16777215
642 
643 #define ISCSI_DEF_FIRST_BURST_LEN		65536
644 #define ISCSI_MIN_FIRST_BURST_LEN		512
645 #define ISCSI_MAX_FIRST_BURST_LEN		16777215
646 
647 #define ISCSI_DEF_MAX_BURST_LEN			262144
648 #define ISCSI_MIN_MAX_BURST_LEN			512
649 #define ISCSI_MAX_MAX_BURST_LEN			16777215
650 
651 #define ISCSI_DEF_TIME2WAIT			2
652 
653 #define ISCSI_NAME_LEN				224
654 
655 /************************* RFC 3720 End *****************************/
656 
657 #endif /* ISCSI_PROTO_H */
658