1.\" 2.\" Copyright (c) 1998 Kenneth D. Merry. 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. The name of the author may not be used to endorse or promote products 14.\" derived from this software without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD: src/lib/libcam/cam_cdbparse.3,v 1.3.2.11 2002/12/29 16:35:35 schweikh Exp $ 29.\" $DragonFly: src/lib/libcam/cam_cdbparse.3,v 1.5 2008/05/02 02:05:04 swildner Exp $ 30.\" 31.\" This man page borrows heavily from the old scsi(3) man page, which had 32.\" the following copyright: 33.\" 34.\" Copyright (c) 1994 HD Associates (hd@world.std.com) 35.\" All rights reserved. 36.\" 37.\" Redistribution and use in source and binary forms, with or without 38.\" modification, are permitted provided that the following conditions 39.\" are met: 40.\" 1. Redistributions of source code must retain the above copyright 41.\" notice, this list of conditions and the following disclaimer. 42.\" 2. Redistributions in binary form must reproduce the above copyright 43.\" notice, this list of conditions and the following disclaimer in the 44.\" documentation and/or other materials provided with the distribution. 45.\" 3. All advertising materials mentioning features or use of this software 46.\" must display the following acknowledgement: 47.\" This product includes software developed by HD Associates 48.\" 4. Neither the name of the HD Associates nor the names of its contributors 49.\" may be used to endorse or promote products derived from this software 50.\" without specific prior written permission. 51.\" 52.\" THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES``AS IS'' AND 53.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55.\" ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE 56.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62.\" SUCH DAMAGE. 63.\" 64.\" 65.Dd October 13, 1998 66.Os 67.Dt CAM_CDBPARSE 3 68.Sh NAME 69.Nm csio_build , 70.Nm csio_build_visit , 71.Nm csio_decode , 72.Nm csio_decode_visit , 73.Nm buff_decode , 74.Nm buff_decode_visit , 75.Nm csio_encode , 76.Nm csio_encode_visit , 77.Nm buff_encode_visit 78.Nd CAM user library SCSI buffer parsing routines 79.Sh LIBRARY 80.Lb libcam 81.Sh SYNOPSIS 82.In stdio.h 83.In camlib.h 84.Ft int 85.Fo csio_build 86.Fa "struct ccb_scsiio *csio" 87.Fa "u_int8_t *data_ptr" 88.Fa "u_int32_t dxfer_len" 89.Fa "u_int32_t flags" 90.Fa "int retry_count" 91.Fa "int timeout" 92.Fa "const char *cmd_spec" 93.Fa "..." 94.Fc 95.Ft int 96.Fo csio_build_visit 97.Fa "struct ccb_scsiio *csio" 98.Fa "u_int8_t *data_ptr" 99.Fa "u_int32_t dxfer_len" 100.Fa "u_int32_t flags" 101.Fa "int retry_count" 102.Fa "int timeout" 103.Fa "const char *cmd_spec" 104.Fa "int (*arg_get)(void *hook, char *field_name)" 105.Fa "void *gethook" 106.Fc 107.Ft int 108.Fo csio_decode 109.Fa "struct ccb_scsiio *csio" 110.Fa "const char *fmt" 111.Fa "..." 112.Fc 113.Ft int 114.Fo csio_decode_visit 115.Fa "struct ccb_scsiio *csio" 116.Fa "const char *fmt" 117.Fa "void (*arg_put)(void *hook" 118.Fa "int letter" 119.Fa "void *val" 120.Fa "int count" 121.Fa "char *name)" 122.Fa "void *puthook" 123.Fc 124.Ft int 125.Fo buff_decode 126.Fa "u_int8_t *buff" 127.Fa "size_t len" 128.Fa "const char *fmt" 129.Fa "..." 130.Fc 131.Ft int 132.Fo buff_decode_visit 133.Fa "u_int8_t *buff" 134.Fa "size_t len" 135.Fa "const char *fmt" 136.Fa "void (*arg_put)(void *, int, void *, int, char *)" 137.Fa "void *puthook" 138.Fc 139.Ft int 140.Fo csio_encode 141.Fa "struct ccb_scsiio *csio" 142.Fa "const char *fmt" 143.Fa "..." 144.Fc 145.Ft int 146.Fo csio_encode_visit 147.Fa "struct ccb_scsiio *csio" 148.Fa "const char *fmt" 149.Fa "int (*arg_get)(void *hook, char *field_name)" 150.Fa "void *gethook" 151.Fc 152.Ft int 153.Fo buff_encode_visit 154.Fa "u_int8_t *buff" 155.Fa "size_t len" 156.Fa "const char *fmt" 157.Fa "int (*arg_get)(void *hook, char *field_name)" 158.Fa "void *gethook" 159.Fc 160.Sh DESCRIPTION 161The CAM buffer/CDB encoding and decoding routines provide a relatively easy 162migration path for userland 163.Tn SCSI 164applications written with the similarly-named 165.Va scsireq_ Ns * 166functions from the old 167.Fx 168.Tn SCSI 169layer. 170.Pp 171These functions may be used in new applications, but users may find it 172easier to use the various SCSI CCB building functions included with the 173.Xr cam 3 174library. (e.g.\& 175.Fn cam_fill_csio , 176.Fn scsi_start_stop , 177and 178.Fn scsi_read_write ) 179.Pp 180.Fn csio_build 181builds up a 182.Va ccb_scsiio 183structure based on the information provided in 184the variable argument list. 185It gracefully handles a NULL 186.Fa data_ptr 187argument passed to it. 188.Pp 189.Fa dxfer_len 190is the length of the data phase; the data transfer direction is 191determined by the 192.Fa flags 193argument. 194.Pp 195.Fa data_ptr 196is the data buffer used during the 197.Tn SCSI 198data phase. If no data is to be 199transferred for the 200.Tn SCSI 201command in question, this should be set to NULL. If there is data to 202transfer for the command, this buffer must be at least 203.Fa dxfer_len 204long. 205.Pp 206.Fa flags 207are the flags defined in 208.In bus/cam/cam_ccb.h : 209.Bd -literal 210/* Common CCB header */ 211/* CAM CCB flags */ 212typedef enum { 213 CAM_CDB_POINTER = 0x00000001,/* The CDB field is a pointer */ 214 CAM_QUEUE_ENABLE = 0x00000002,/* SIM queue actions are enabled */ 215 CAM_CDB_LINKED = 0x00000004,/* CCB contains a linked CDB */ 216 CAM_SCATTER_VALID = 0x00000010,/* Scatter/gather list is valid */ 217 CAM_DIS_AUTOSENSE = 0x00000020,/* Disable autosense feature */ 218 CAM_DIR_RESV = 0x00000000,/* Data direction (00:reserved) */ 219 CAM_DIR_IN = 0x00000040,/* Data direction (01:DATA IN) */ 220 CAM_DIR_OUT = 0x00000080,/* Data direction (10:DATA OUT) */ 221 CAM_DIR_NONE = 0x000000C0,/* Data direction (11:no data) */ 222 CAM_DIR_MASK = 0x000000C0,/* Data direction Mask */ 223 CAM_SOFT_RST_OP = 0x00000100,/* Use Soft reset alternative */ 224 CAM_ENG_SYNC = 0x00000200,/* Flush resid bytes on complete */ 225 CAM_DEV_QFRZDIS = 0x00000400,/* Disable DEV Q freezing */ 226 CAM_DEV_QFREEZE = 0x00000800,/* Freeze DEV Q on execution */ 227 CAM_HIGH_POWER = 0x00001000,/* Command takes a lot of power */ 228 CAM_SENSE_PTR = 0x00002000,/* Sense data is a pointer */ 229 CAM_SENSE_PHYS = 0x00004000,/* Sense pointer is physical addr*/ 230 CAM_TAG_ACTION_VALID = 0x00008000,/* Use the tag action in this ccb*/ 231 CAM_PASS_ERR_RECOVER = 0x00010000,/* Pass driver does err. recovery*/ 232 CAM_DIS_DISCONNECT = 0x00020000,/* Disable disconnect */ 233 CAM_SG_LIST_PHYS = 0x00040000,/* SG list has physical addrs. */ 234 CAM_MSG_BUF_PHYS = 0x00080000,/* Message buffer ptr is physical*/ 235 CAM_SNS_BUF_PHYS = 0x00100000,/* Autosense data ptr is physical*/ 236 CAM_DATA_PHYS = 0x00200000,/* SG/Buffer data ptrs are phys. */ 237 CAM_CDB_PHYS = 0x00400000,/* CDB pointer is physical */ 238 CAM_ENG_SGLIST = 0x00800000,/* SG list is for the HBA engine */ 239 240/* Phase cognizant mode flags */ 241 CAM_DIS_AUTOSRP = 0x01000000,/* Disable autosave/restore ptrs */ 242 CAM_DIS_AUTODISC = 0x02000000,/* Disable auto disconnect */ 243 CAM_TGT_CCB_AVAIL = 0x04000000,/* Target CCB available */ 244 CAM_TGT_PHASE_MODE = 0x08000000,/* The SIM runs in phase mode */ 245 CAM_MSGB_VALID = 0x20000000,/* Message buffer valid */ 246 CAM_STATUS_VALID = 0x40000000,/* Status buffer valid */ 247 CAM_DATAB_VALID = 0x80000000,/* Data buffer valid */ 248 249/* Host target Mode flags */ 250 CAM_TERM_IO = 0x20000000,/* Terminate I/O Message sup. */ 251 CAM_DISCONNECT = 0x40000000,/* Disconnects are mandatory */ 252 CAM_SEND_STATUS = 0x80000000,/* Send status after data phase */ 253} ccb_flags; 254.Ed 255.Pp 256Multiple flags should be ORed together. Any of the CCB flags may be used, 257although it is worth noting several important ones here: 258.Bl -tag -width CAM_PASS_ERR_RECOVER 259.It Dv CAM_DIR_IN 260This indicates that the operation in question is a read operation. i.e., 261data is being read from the 262.Tn SCSI 263device to the user-supplied buffer. 264.It Dv CAM_DIR_OUT 265This indicates that the operation is a write operation. i.e. data is being 266written from the user-supplied buffer to the device. 267.It Dv CAM_DIR_NONE 268This indicates that there is no data to be transferred for this command. 269.It Dv CAM_DEV_QFRZDIS 270This flag disables device queue freezing as an error recovery mechanism. 271.It Dv CAM_PASS_ERR_RECOVER 272This flag tells the 273.Xr pass 4 274driver to enable error recovery. The default is to not perform error 275recovery, which means that the retry count won't be honored without this 276flag, among other things. 277.It Dv CAM_DATA_PHYS 278This indicates that the address contained in 279.Fa data_ptr 280is a physical address, not a virtual address. 281.El 282.Pp 283The 284.Fa retry_count 285tells the kernel how many times to retry the command in question. The 286retry count is ignored unless the 287.Xr pass 4 288driver is told to enable error recovery via the 289.Dv CAM_PASS_ERR_RECOVER 290flag. 291.Pp 292The 293.Fa timeout 294tells the kernel how long to wait for the given command to complete. If 295the timeout expires and the command hasn't completed, the CCB will be 296returned from the kernel with an appropriate error status. 297.Pp 298.Fa cmd_spec 299is a CDB format specifier used to build up the SCSI CDB. 300This text string is made up of a list of field specifiers. Field 301specifiers specify the value for each CDB field (including indicating 302that the value be taken from the next argument in the 303variable argument list), the width 304of the field in bits or bytes, and an optional name. White space is 305ignored, and the pound sign ('#') introduces a comment that ends at the 306end of the current line. 307.Pp 308The optional name is the first part of a field specifier and 309is in curly braces. The text in curly braces in this example are 310the names: 311.Dl "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page" 312.Pp 313This field specifier has two one bit fields and one six bit field. 314The second one bit field is the constant value 0 and the first 315one bit field and the six bit field are taken from the variable 316argument list. 317Multi byte fields are swapped into the SCSI byte order in the 318CDB and white space is ignored. 319.Pp 320When the field is a hex value or the letter v, (e.g., 321.Fa "1A" 322or 323.Fa "v" ) 324then a single byte value 325is copied to the next unused byte of the CDB. 326When the letter 327.Fa v 328is used the next integer argument is taken from the variable argument list 329and that value used. 330.Pp 331A constant hex value followed by a field width specifier or the letter 332.Fa v 333followed by a field width specifier (e.g., 334.Fa 3:4 , 335.Fa 3:b4 , 336.Fa 3:i3 , 337.Fa v:i3 ) 338specifies a field of a given bit or byte width. 339Either the constant value or (for the V specifier) the next integer value from 340the variable argument list is copied to the next unused 341bits or bytes of the CDB. 342.Pp 343A decimal number or the letter 344.Fa b 345followed by a decimal number field width indicates a bit field of that width. 346The bit fields are packed as tightly as possible beginning with the 347high bit (so that it reads the same as the SCSI spec), and a new byte of 348the CDB is started whenever a byte fills completely or when an 349.Fa i 350field is encountered. 351.Pp 352A field width specifier consisting of the letter 353.Fa i 354followed by either 3551, 2, 3 or 4 indicates a 1, 2, 3 or 4 byte integral value that must 356be swapped into SCSI byte order (MSB first). 357.Pp 358For the 359.Fa v 360field specifier the next integer argument is taken from the variable argument 361list and that value is used swapped into SCSI byte order. 362.Pp 363.Fn csio_build_visit 364operates similarly to 365.Fn csio_build , 366except that the values to substitute for variable arguments in 367.Fa cmd_spec 368are retrieved via the 369.Fn arg_get 370function passed in to 371.Fn csio_build_visit 372instead of via 373.Xr stdarg 3 . 374The 375.Fn arg_get 376function takes two arguments: 377.Bl -tag -width field_name 378.It Fa gethook 379is passed into the 380.Fn arg_get 381function at each invocation. This enables the 382.Fn arg_get 383function to keep some state in between calls without using global or static 384variables. 385.It Fa field_name 386is the field name supplied in 387.Fa fmt , 388if any. 389.El 390.Pp 391.Fn csio_decode 392is used to decode information from the data in phase of the SCSI 393transfer. 394.Pp 395The decoding is similar to 396the command specifier processing of 397.Fn csio_build 398except that the data is extracted from the data pointed to by 399.Fa csio->data_ptr . 400The stdarg list should be pointers to integers instead of integer 401values. 402A seek field type and a suppression modifier are added. 403The 404.Fa * 405suppression modifier (e.g., 406.Fa *i3 407or 408.Fa *b4 ) 409suppresses assignment from the field and can be used to skip 410over bytes or bits in the data, without having to copy 411them to a dummy variable in the arg list. 412.Pp 413The seek field type 414.Fa s 415permits you to skip over data. 416This seeks to an absolute position 417.Pq Fa s3 418or a relative position 419.Pq Fa s+3 420in the data, based on whether or not the presence of the '+' sign. 421The seek value can be specified as 422.Fa v 423and the next integer value from the argument list will be 424used as the seek value. 425.Pp 426.Fn csio_decode_visit 427operates like 428.Fn csio_decode 429except that instead of placing the decoded contents of the buffer in 430variadic arguments, the decoded buffer contents are returned to the user 431via the 432.Fn arg_put 433function that is passed in. 434The 435.Fn arg_put 436function takes several arguments: 437.Bl -tag -width letter 438.It Fa hook 439The "hook" is a mechanism to allow the 440.Fn arg_put 441function to save state in between calls. 442.It Fa letter 443is the letter describing the format of the argument being passed into the 444function. 445.It Fa val 446is a void pointer to the value being passed into the function. 447.It Fa count 448is the size of the value being passed into the 449.Fn arg_put 450function. The argument format determines the unit of measure. 451.It Fa name 452This is a text description of the field, if one was provided in the 453.Fa fmt . 454.El 455.Pp 456.Fn buff_decode 457decodes an arbitrary data buffer using the method 458described above for 459.Fn csio_decode . 460.Pp 461.Fn buff_decode_visit 462decodes an arbitrary data buffer using the method described above for 463.Fn csio_decode_visit . 464.Pp 465.Fn csio_encode 466encodes the 467.Fa data_ptr 468portion (not the CDB!) of a 469.Va ccb_scsiio 470structure, using the method described above for 471.Fn csio_build . 472.Pp 473.Fn csio_encode_visit 474encodes the 475.Fa data_ptr 476portion (not the CDB!) of a 477.Va ccb_scsiio 478structure, using the method described above for 479.Fn csio_build_visit . 480.Pp 481.Fn buff_encode_visit 482encodes an arbitrary data pointer, using the method described 483above for 484.Fn csio_build_visit . 485.Sh RETURN VALUES 486.Fn csio_build , 487.Fn csio_build_visit , 488.Fn csio_encode , 489.Fn csio_encode_visit , 490and 491.Fn buff_encode_visit 492return the number of fields processed. 493.Pp 494.Fn csio_decode , 495.Fn csio_decode_visit , 496.Fn buff_decode , 497and 498.Fn buff_decode_visit 499return the number of assignments performed. 500.Sh SEE ALSO 501.Xr cam 3 , 502.Xr pass 4 , 503.Xr camcontrol 8 504.Sh HISTORY 505The CAM versions of these functions are based upon similar functions 506implemented for the old 507.Fx 508.Tn SCSI 509layer. The encoding/decoding functions in the old 510.Tn SCSI 511code were written by Peter Dufault. 512.Pp 513Many systems have comparable interfaces to permit a user to construct a 514SCSI command in user space. 515.Pp 516The old 517.Va scsireq 518data structure was almost identical to the SGI /dev/scsi data 519structure. If anyone knows the name of the authors it should 520go here; Peter Dufault first read about it in a 1989 Sun Expert magazine. 521.Pp 522The new CCB data structures are derived from the CAM-2 and CAM-3 523specifications. 524.Pp 525.An Peter Dufault 526implemented a clone of SGI's interface in 527.Bx 386 528that 529led to the original 530.Fx 531.Tn SCSI 532library and the related kernel ioctl. 533If anyone needs that for compatibility contact dufault@hda.com. 534.Sh AUTHORS 535Kenneth Merry implemented the CAM versions of these encoding and decoding 536functions. This current work is based upon earlier work by Peter Dufault. 537.Sh BUGS 538There should probably be a function that encodes both the CDB and the data 539buffer portions of a 540.Tn SCSI 541CCB. I discovered this while implementing the arbitrary command execution 542code in 543.Xr camcontrol 8 , 544but I haven't yet had time to implement such a function. 545.Pp 546Some of the CCB flag descriptions really don't belong here. Rather they 547belong in a generic CCB man page. Since that man page hasn't yet been 548written, the shorter descriptions here will have to suffice. 549