summaryrefslogtreecommitdiffstats
path: root/lib/libcam/cam_cdbparse.3
blob: 905e652fc9fe4b4815f792a3f5bbc91673e67b87 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
.\"
.\" Copyright (c) 1998 Kenneth D. Merry.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.\" This man page borrows heavily from the old scsi(3) man page, which had
.\" the following copyright:
.\"
.\" Copyright (c) 1994 HD Associates (hd@world.std.com)
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by HD Associates
.\" 4. Neither the name of the HD Associates nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"
.Dd October 13, 1998
.Os FreeBSD
.Dt CAM_CDBPARSE 3
.Sh NAME
.Nm csio_build ,
.Nm csio_build_visit ,
.Nm csio_decode ,
.Nm csio_decode_visit ,
.Nm buff_decode ,
.Nm buff_decode_visit ,
.Nm csio_encode ,
.Nm csio_encode_visit ,
.Nm buff_encode_visit
.Nd CAM user library SCSI buffer parsing routines
.Sh LIBRARY
.Lb libcam
.Sh SYNOPSIS
.Fd #include <stdio.h>
.Fd #include <camlib.h>
.Ft int
.Fo csio_build
.Fa "struct ccb_scsiio *csio"
.Fa "u_int8_t *data_ptr"
.Fa "u_int32_t dxfer_len"
.Fa "u_int32_t flags"
.Fa "int retry_count"
.Fa "int timeout"
.Fa "char *cmd_spec"
.Fa "..."
.Fc
.Ft int
.Fo csio_build_visit
.Fa "struct ccb_scsiio *csio"
.Fa "u_int8_t *data_ptr"
.Fa "u_int32_t dxfer_len"
.Fa "u_int32_t flags"
.Fa "int retry_count"
.Fa "int timeout"
.Fa "char *cmd_spec"
.Fa "int (*arg_get)(void *hook, char *field_name)"
.Fa "void *gethook"
.Fc
.Ft int
.Fo csio_decode
.Fa "struct ccb_scsiio *csio"
.Fa "char *fmt"
.Fa "..."
.Fc
.Ft int
.Fo csio_decode_visit
.Fa "struct ccb_scsiio *csio"
.Fa "char *fmt"
.Fa "void (*arg_put)(void *hook"
.Fa "int letter"
.Fa "void *val"
.Fa "int count"
.Fa "char *name)"
.Fa "void *puthook"
.Fc
.Ft int
.Fo buff_decode
.Fa "u_int8_t *buff"
.Fa "size_t len"
.Fa "char *fmt"
.Fa "..."
.Fc
.Ft int
.Fo buff_decode_visit
.Fa "u_int8_t *buff"
.Fa "size_t len"
.Fa "char *fmt"
.Fa "void (*arg_put)(void *, int, void *, int, char *)"
.Fa "void *puthook"
.Fc
.Ft int
.Fo csio_encode
.Fa "struct ccb_scsiio *csio"
.Fa "char *fmt"
.Fa "..."
.Fc
.Ft int
.Fo csio_encode_visit
.Fa "struct ccb_scsiio *csio"
.Fa "char *fmt"
.Fa "int (*arg_get)(void *hook, char *field_name)"
.Fa "void *gethook"
.Fc
.Ft int
.Fo buff_encode_visit
.Fa "u_int8_t *buff"
.Fa "size_t len"
.Fa "char *fmt"
.Fa "int (*arg_get)(void *hook, char *field_name)"
.Fa "void *gethook"
.Fc
.Sh DESCRIPTION
The CAM buffer/CDB encoding and decoding routines provide a relatively easy
migration path for userland
.Tn SCSI
applications written with the similarly-named
.Va scsireq_ Ns *
functions from the old
.Fx
.Tn SCSI
layer.
.Pp
These functions may be used in new applications, but users may find it
easier to use the various SCSI CCB building functions included with the
.Xr cam 3
library.  (e.g. 
.Fn cam_fill_csio ,
.Fn scsi_start_stop ,
and
.Fn scsi_read_write )
.Pp
.Fn csio_build
builds up a
.Va ccb_scsiio
structure based on the information provided in
the variable argument list.
It gracefully handles a NULL
.Fa data_ptr
argument passed to it.
.Pp
.Fa dxfer_len
is the length of the data phase; the data transfer direction is
determined by the
.Fa flags
argument.
.Pp
.Fa data_ptr
is the data buffer used during the
.Tn SCSI
data phase.  If no data is to be
transferred for the
.Tn SCSI
command in question, this should be set to NULL.  If there is data to
transfer for the command, this buffer must be at least
.Fa dxfer_len
long.
.Pp
.Fa flags
are the flags defined in
.Aq Pa cam/cam_ccb.h :
.Bd -literal
/* Common CCB header */
/* CAM CCB flags */
typedef enum {
     CAM_CDB_POINTER       = 0x00000001,/* The CDB field is a pointer    */
     CAM_QUEUE_ENABLE      = 0x00000002,/* SIM queue actions are enabled */
     CAM_CDB_LINKED        = 0x00000004,/* CCB contains a linked CDB     */
     CAM_SCATTER_VALID     = 0x00000010,/* Scatter/gather list is valid  */
     CAM_DIS_AUTOSENSE     = 0x00000020,/* Disable autosense feature     */
     CAM_DIR_RESV          = 0x00000000,/* Data direction (00:reserved)  */
     CAM_DIR_IN            = 0x00000040,/* Data direction (01:DATA IN)   */
     CAM_DIR_OUT           = 0x00000080,/* Data direction (10:DATA OUT)  */
     CAM_DIR_NONE          = 0x000000C0,/* Data direction (11:no data)   */
     CAM_DIR_MASK          = 0x000000C0,/* Data direction Mask		 */
     CAM_SOFT_RST_OP       = 0x00000100,/* Use Soft reset alternative    */
     CAM_ENG_SYNC          = 0x00000200,/* Flush resid bytes on complete */
     CAM_DEV_QFRZDIS       = 0x00000400,/* Disable DEV Q freezing	 */
     CAM_DEV_QFREEZE       = 0x00000800,/* Freeze DEV Q on execution     */
     CAM_HIGH_POWER        = 0x00001000,/* Command takes a lot of power  */
     CAM_SENSE_PTR         = 0x00002000,/* Sense data is a pointer	 */
     CAM_SENSE_PHYS        = 0x00004000,/* Sense pointer is physical addr*/
     CAM_TAG_ACTION_VALID  = 0x00008000,/* Use the tag action in this ccb*/
     CAM_PASS_ERR_RECOVER  = 0x00010000,/* Pass driver does err. recovery*/
     CAM_DIS_DISCONNECT    = 0x00020000,/* Disable disconnect		 */
     CAM_SG_LIST_PHYS      = 0x00040000,/* SG list has physical addrs.   */
     CAM_MSG_BUF_PHYS      = 0x00080000,/* Message buffer ptr is physical*/
     CAM_SNS_BUF_PHYS      = 0x00100000,/* Autosense data ptr is physical*/
     CAM_DATA_PHYS         = 0x00200000,/* SG/Buffer data ptrs are phys. */
     CAM_CDB_PHYS          = 0x00400000,/* CDB poiner is physical	 */
     CAM_ENG_SGLIST        = 0x00800000,/* SG list is for the HBA engine */

/* Phase cognizant mode flags */
     CAM_DIS_AUTOSRP       = 0x01000000,/* Diable autosave/restore ptrs	*/
     CAM_DIS_AUTODISC      = 0x02000000,/* Disable auto disconnect	*/
     CAM_TGT_CCB_AVAIL     = 0x04000000,/* Target CCB available		*/
     CAM_TGT_PHASE_MODE    = 0x08000000,/* The SIM runs in phase mode	*/
     CAM_MSGB_VALID        = 0x20000000,/* Message buffer valid		*/
     CAM_STATUS_VALID      = 0x40000000,/* Status buffer valid		*/
     CAM_DATAB_VALID       = 0x80000000,/* Data buffer valid		*/
	
/* Host target Mode flags */
     CAM_TERM_IO           = 0x20000000,/* Terminate I/O Message sup.    */
     CAM_DISCONNECT        = 0x40000000,/* Disconnects are mandatory     */
     CAM_SEND_STATUS       = 0x80000000,/* Send status after data phase  */
} ccb_flags;
.Ed
.Pp
Multiple flags should be ORed together.  Any of the CCB flags may be used,
although it is worth noting several important ones here:
.Pp
.Bl -tag -width CAM_PASS_ERR_RECOVER
.It Dv CAM_DIR_IN
This indicates that the operation in question is a read operation.  i.e.,
data is being read from the
.Tn SCSI
device to the user-supplied buffer.
.It Dv CAM_DIR_OUT
This indicates that the operation is a write operation.  i.e. data is being
written from the user-supplied buffer to the device.
.It Dv CAM_DIR_NONE
This indicates that there is no data to be transferred for this command.
.It Dv CAM_DEV_QFRZDIS
This flag disables device queue freezing as an error recovery mechanism.
.It Dv CAM_PASS_ERR_RECOVER
This flag tells the
.Xr pass 4
driver to enable error recovery.  The default is to not perform error
recovery, which means that the retry count won't be honored without this
flag, among other things.
.It Dv CAM_DATA_PHYS
This indicates that the address contained in
.Fa data_ptr
is a physical address, not a virtual address.
.El
.Pp
The
.Fa retry_count
tells the kernel how many times to retry the command in question.  The
retry count is ignored unless the
.Xr pass 4
driver is told to enable error recovery via the
.Dv CAM_PASS_ERR_RECOVER
flag.
.Pp
The 
.Fa timeout
tells the kernel how long to wait for the given command to complete.  If
the timeout expires and the command hasn't completed, the CCB will be
returned from the kernel with an appropriate error status.
.Pp
.Fa cmd_spec
is a CDB format specifier used to build up the SCSI CDB.
This text string is made up of a list of field specifiers.  Field
specifiers specify the value for each CDB field (including indicating
that the value be taken from the next argument in the
variable argument list), the width
of the field in bits or bytes, and an optional name.  White space is
ignored, and the pound sign ('#') introduces a comment that ends at the
end of the current line.
.Pp
The optional name is the first part of a field specifier and
is in curly braces.  The text in curly braces in this example are
the names:
.Dl "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page"
.Pp
This field specifier has two one bit fields and one six bit field.
The second one bit field is the constant value 0 and the first
one bit field and the six bit field are taken from the variable
argument list.
Multi byte fields are swapped into the SCSI byte order in the
CDB and white space is ignored.
.Pp
When the field is a hex value or the letter v, (e.g.,
.Fa "1A"
or
.Fa "v" )
then a single byte value
is copied to the next unused byte of the CDB.
When the letter
.Fa v
is used the next integer argument is taken from the variable argument list
and that value used.
.Pp
A constant hex value followed by a field width specifier or the letter
.Fa v
followed by a field width specifier (e.g.,
.Fa 3:4 ,
.Fa 3:b4 ,
.Fa 3:i3 ,
.Fa v:i3 )
specifies a field of a given bit or byte width.
Either the constant value or (for the V specifier) the next integer value from
the variable argument list is copied to the next unused
bits or bytes of the CDB.
.Pp
A decimal number or the letter
.Fa b
followed by a decimal number field width indicates a bit field of that width.
The bit fields are packed as tightly as possible beginning with the
high bit (so that it reads the same as the SCSI spec), and a new byte of
the CDB is started whenever a byte fills completely or when an
.Fa i
field is encountered.
.Pp
A field width specifier consisting of the letter
.Fa i
followed by either
1, 2, 3 or 4 indicates a 1, 2, 3 or 4 byte integral value that must
be swapped into SCSI byte order (MSB first).
.Pp
For the
.Fa v
field specifier the next integer argument is taken from the variable argument
list and that value is used swapped into SCSI byte order.
.Pp
.Fn csio_build_visit
operates similarly to
.Fn csio_build ,
except that the values to substitute for variable arguments in
.Fa cmd_spec
are retrieved via the
.Fn arg_get
function passed in to
.Fn csio_build_visit 
instead of via
.Xr stdarg 3 .
The
.Fn arg_get
function takes two arguments:
.Bl -tag -width field_name
.It Fa gethook
is passed into the
.Fn arg_get
function at each invocation.  This enables the
.Fn arg_get
function to keep some state in between calls without using global or static
variables.
.It Fa field_name
is the field name supplied in
.Fa fmt ,
if any.
.El
.Pp
.Fn csio_decode
is used to decode information from the data in phase of the SCSI
transfer.
.Pp
The decoding is similar to
the command specifier processing of
.Fn csio_build
except that the data is extracted from the data pointed to by
.Fa csio->data_ptr .
The stdarg list should be pointers to integers instead of integer
values.
A seek field type and a suppression modifier are added.
The
.Fa *
suppression modifier (e.g.,
.Fa *i3
or
.Fa *b4 )
suppresses assignment from the field and can be used to skip
over bytes or bits in the data, without having to copy
them to a dummy variable in the arg list.
.Pp
The seek field type
.Fa s
permits you to skip over data.
This seeks to an absolute position (
.Fa s3 )
or a relative position (
.Fa s+3 )
in the data, based on whether or not the presence of the '+' sign.
The seek value can be specified as
.Fa v
and the next integer value from the argument list will be
used as the seek value.
.Pp
.Fn csio_decode_visit
operates like
.Fn csio_decode
except that instead of placing the decoded contents of the buffer in
varardic arguments, the decoded buffer contents are returned to the user
via the
.Fn arg_put
function that is passed in.
The
.Fn arg_put
function takes several arguments:
.Bl -tag -width letter
.It Fa hook
The "hook" is a mechanism to allow the
.Fn arg_put
function to save state in between calls.
.It Fa letter
is the letter describing the format of the argument being passed into the
function.
.It Fa val
is a void pointer to the value being passed into the function.
.It Fa count
is the size of the value being passed into the
.Fn arg_put
function.  The argument format determines the unit of measure.
.It Fa name
This is a text description of the field, if one was provided in the
.Fa fmt .
.El
.Pp
.Fn buff_decode
decodes an arbitrary data buffer using the method
described above for
.Fn csio_decode .
.Pp
.Fn buff_decode_visit
decodes an arbitrary data buffer using the method described above for
.Fn csio_decode_visit .
.Pp
.Fn csio_encode
encodes the
.Fa data_ptr
portion (not the CDB!) of a
.Va ccb_scsiio
structure, using the method described above for
.Fn csio_build .
.Pp
.Fn csio_encode_visit
encodes the
.Fa data_ptr
portion (not the CDB!) of a
.Va ccb_scsiio
structure, using the method described above for
.Fn csio_build_visit .
.Pp
.Fn buff_encode_visit
encodes an arbitrary data pointer, using the method described
above for
.Fn csio_build_visit .
.Sh RETURN VALUES
.Fn csio_build ,
.Fn csio_build_visit ,
.Fn csio_encode ,
.Fn csio_encode_visit ,
and
.Fn buff_encode_visit
return the number of fields processed.
.Pp
.Fn csio_decode ,
.Fn csio_decode_visit ,
.Fn buff_decode ,
and
.Fn buff_decode_visit
return the number of assignments performed.
.Sh SEE ALSO
.Xr cam 3 ,
.Xr pass 4 ,
.Xr camcontrol 8
.Sh HISTORY
.Pp
The CAM versions of these functions are based upon similar functions
implemented for the old
.Fx
.Tn SCSI
layer.  The encoding/decoding functions in the old
.Tn SCSI
code were written by Peter Dufault.
.Pp
Many systems have comparable interfaces to permit a user to construct a
SCSI command in user space.
.Pp
The old
.Va scsireq
data structure was almost identical to the SGI /dev/scsi data
structure.  If anyone knows the name of the authors it should
go here; Peter Dufault first read about it in a 1989 Sun Expert magazine.
.Pp
The new CCB data structures are derived from the CAM-2 and CAM-3
specifications.
.Pp
Peter Dufault implemented a clone of SGI's interface in 386bsd that
led to the original
.Fx
.Tn SCSI
library and the related kernel ioctl.
If anyone needs that for compatibility contact dufault@hda.com.
.Sh AUTHORS
Kenneth Merry implemented the CAM versions of these encoding and decoding
functions.  This current work is based upon earlier work by Peter Dufault.
.Sh BUGS
There should probably be a function that encodes both the CDB and the data
buffer portions of a
.Tn SCSI
CCB.  I discovered this while implementing the arbitrary command execution
code in
.Xr camcontrol 8 ,
but I haven't yet had time to implement such a function.
.Pp
Some of the CCB flag descriptions really don't belong here.  Rather they
belong in a generic CCB man page.  Since that man page hasn't yet been
written, the shorter descriptions here will have to suffice.
OpenPOWER on IntegriCloud