xref: /openbmc/linux/include/scsi/iscsi_proto.h (revision 762f99f4f3cb41a775b5157dd761217beba65873)
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