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.\" 30.\" This man page borrows heavily from the old scsi(3) man page, which had 31.\" the following copyright: 32.\" 33.\" Copyright (c) 1994 HD Associates (hd@world.std.com) 34.\" All rights reserved. 35.\" 36.\" Redistribution and use in source and binary forms, with or without 37.\" modification, are permitted provided that the following conditions 38.\" are met: 39.\" 1. Redistributions of source code must retain the above copyright 40.\" notice, this list of conditions and the following disclaimer. 41.\" 2. Redistributions in binary form must reproduce the above copyright 42.\" notice, this list of conditions and the following disclaimer in the 43.\" documentation and/or other materials provided with the distribution. 44.\" 3. All advertising materials mentioning features or use of this software 45.\" must display the following acknowledgement: 46.\" This product includes software developed by HD Associates 47.\" 4. Neither the name of the HD Associates nor the names of its contributors 48.\" may be used to endorse or promote products derived from this software 49.\" without specific prior written permission. 50.\" 51.\" THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES``AS IS'' AND 52.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 53.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 54.\" ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE 55.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 56.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 57.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 58.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 59.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 60.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 61.\" SUCH DAMAGE. 62.\" 63.Dd October 13, 1998 64.Dt CAM_CDBPARSE 3 65.Os 66.Sh NAME 67.Nm csio_build , 68.Nm csio_build_visit , 69.Nm csio_decode , 70.Nm csio_decode_visit , 71.Nm buff_decode , 72.Nm buff_decode_visit , 73.Nm csio_encode , 74.Nm csio_encode_visit , 75.Nm buff_encode_visit 76.Nd CAM user library SCSI buffer parsing routines 77.Sh LIBRARY 78.Lb libcam 79.Sh SYNOPSIS 80.In stdio.h 81.In camlib.h 82.Ft int 83.Fo csio_build 84.Fa "struct ccb_scsiio *csio" 85.Fa "u_int8_t *data_ptr" 86.Fa "u_int32_t dxfer_len" 87.Fa "u_int32_t flags" 88.Fa "int retry_count" 89.Fa "int timeout" 90.Fa "const char *cmd_spec" 91.Fa "..." 92.Fc 93.Ft int 94.Fo csio_build_visit 95.Fa "struct ccb_scsiio *csio" 96.Fa "u_int8_t *data_ptr" 97.Fa "u_int32_t dxfer_len" 98.Fa "u_int32_t flags" 99.Fa "int retry_count" 100.Fa "int timeout" 101.Fa "const char *cmd_spec" 102.Fa "int (*arg_get)(void *hook, char *field_name)" 103.Fa "void *gethook" 104.Fc 105.Ft int 106.Fo csio_decode 107.Fa "struct ccb_scsiio *csio" 108.Fa "const char *fmt" 109.Fa "..." 110.Fc 111.Ft int 112.Fo csio_decode_visit 113.Fa "struct ccb_scsiio *csio" 114.Fa "const char *fmt" 115.Fa "void (*arg_put)(void *hook" 116.Fa "int letter" 117.Fa "void *val" 118.Fa "int count" 119.Fa "char *name)" 120.Fa "void *puthook" 121.Fc 122.Ft int 123.Fo buff_decode 124.Fa "u_int8_t *buff" 125.Fa "size_t len" 126.Fa "const char *fmt" 127.Fa "..." 128.Fc 129.Ft int 130.Fo buff_decode_visit 131.Fa "u_int8_t *buff" 132.Fa "size_t len" 133.Fa "const char *fmt" 134.Fa "void (*arg_put)(void *, int, void *, int, char *)" 135.Fa "void *puthook" 136.Fc 137.Ft int 138.Fo csio_encode 139.Fa "struct ccb_scsiio *csio" 140.Fa "const char *fmt" 141.Fa "..." 142.Fc 143.Ft int 144.Fo csio_encode_visit 145.Fa "struct ccb_scsiio *csio" 146.Fa "const char *fmt" 147.Fa "int (*arg_get)(void *hook, char *field_name)" 148.Fa "void *gethook" 149.Fc 150.Ft int 151.Fo buff_encode_visit 152.Fa "u_int8_t *buff" 153.Fa "size_t len" 154.Fa "const char *fmt" 155.Fa "int (*arg_get)(void *hook, char *field_name)" 156.Fa "void *gethook" 157.Fc 158.Sh DESCRIPTION 159The CAM buffer/CDB encoding and decoding routines provide a relatively easy 160migration path for userland 161.Tn SCSI 162applications written with the similarly-named 163.Va scsireq_ Ns * 164functions from the old 165.Fx 166.Tn SCSI 167layer. 168.Pp 169These functions may be used in new applications, but users may find it 170easier to use the various SCSI CCB building functions included with the 171.Xr cam 3 172library. (e.g.\& 173.Fn cam_fill_csio , 174.Fn scsi_start_stop , 175and 176.Fn scsi_read_write ) 177.Pp 178.Fn csio_build 179builds up a 180.Va ccb_scsiio 181structure based on the information provided in 182the variable argument list. 183It gracefully handles a NULL 184.Fa data_ptr 185argument passed to it. 186.Pp 187.Fa dxfer_len 188is the length of the data phase; the data transfer direction is 189determined by the 190.Fa flags 191argument. 192.Pp 193.Fa data_ptr 194is the data buffer used during the 195.Tn SCSI 196data phase. If no data is to be 197transferred for the 198.Tn SCSI 199command in question, this should be set to NULL. If there is data to 200transfer for the command, this buffer must be at least 201.Fa dxfer_len 202long. 203.Pp 204.Fa flags 205are the flags defined in 206.In bus/cam/cam_ccb.h : 207.Bd -literal 208/* Common CCB header */ 209/* CAM CCB flags */ 210typedef enum { 211 CAM_CDB_POINTER = 0x00000001,/* The CDB field is a pointer */ 212 CAM_QUEUE_ENABLE = 0x00000002,/* SIM queue actions are enabled */ 213 CAM_CDB_LINKED = 0x00000004,/* CCB contains a linked CDB */ 214 CAM_SCATTER_VALID = 0x00000010,/* Scatter/gather list is valid */ 215 CAM_DIS_AUTOSENSE = 0x00000020,/* Disable autosense feature */ 216 CAM_DIR_RESV = 0x00000000,/* Data direction (00:reserved) */ 217 CAM_DIR_IN = 0x00000040,/* Data direction (01:DATA IN) */ 218 CAM_DIR_OUT = 0x00000080,/* Data direction (10:DATA OUT) */ 219 CAM_DIR_NONE = 0x000000C0,/* Data direction (11:no data) */ 220 CAM_DIR_MASK = 0x000000C0,/* Data direction Mask */ 221 CAM_SOFT_RST_OP = 0x00000100,/* Use Soft reset alternative */ 222 CAM_ENG_SYNC = 0x00000200,/* Flush resid bytes on complete */ 223 CAM_DEV_QFRZDIS = 0x00000400,/* Disable DEV Q freezing */ 224 CAM_DEV_QFREEZE = 0x00000800,/* Freeze DEV Q on execution */ 225 CAM_HIGH_POWER = 0x00001000,/* Command takes a lot of power */ 226 CAM_SENSE_PTR = 0x00002000,/* Sense data is a pointer */ 227 CAM_SENSE_PHYS = 0x00004000,/* Sense pointer is physical addr*/ 228 CAM_TAG_ACTION_VALID = 0x00008000,/* Use the tag action in this ccb*/ 229 CAM_PASS_ERR_RECOVER = 0x00010000,/* Pass driver does err. recovery*/ 230 CAM_DIS_DISCONNECT = 0x00020000,/* Disable disconnect */ 231 CAM_SG_LIST_PHYS = 0x00040000,/* SG list has physical addrs. */ 232 CAM_MSG_BUF_PHYS = 0x00080000,/* Message buffer ptr is physical*/ 233 CAM_SNS_BUF_PHYS = 0x00100000,/* Autosense data ptr is physical*/ 234 CAM_DATA_PHYS = 0x00200000,/* SG/Buffer data ptrs are phys. */ 235 CAM_CDB_PHYS = 0x00400000,/* CDB pointer is physical */ 236 CAM_ENG_SGLIST = 0x00800000,/* SG list is for the HBA engine */ 237 238/* Phase cognizant mode flags */ 239 CAM_DIS_AUTOSRP = 0x01000000,/* Disable autosave/restore ptrs */ 240 CAM_DIS_AUTODISC = 0x02000000,/* Disable auto disconnect */ 241 CAM_TGT_CCB_AVAIL = 0x04000000,/* Target CCB available */ 242 CAM_TGT_PHASE_MODE = 0x08000000,/* The SIM runs in phase mode */ 243 CAM_MSGB_VALID = 0x20000000,/* Message buffer valid */ 244 CAM_STATUS_VALID = 0x40000000,/* Status buffer valid */ 245 CAM_DATAB_VALID = 0x80000000,/* Data buffer valid */ 246 247/* Host target Mode flags */ 248 CAM_TERM_IO = 0x20000000,/* Terminate I/O Message sup. */ 249 CAM_DISCONNECT = 0x40000000,/* Disconnects are mandatory */ 250 CAM_SEND_STATUS = 0x80000000,/* Send status after data phase */ 251} ccb_flags; 252.Ed 253.Pp 254Multiple flags should be ORed together. Any of the CCB flags may be used, 255although it is worth noting several important ones here: 256.Bl -tag -width CAM_PASS_ERR_RECOVER 257.It Dv CAM_DIR_IN 258This indicates that the operation in question is a read operation. i.e., 259data is being read from the 260.Tn SCSI 261device to the user-supplied buffer. 262.It Dv CAM_DIR_OUT 263This indicates that the operation is a write operation. i.e. data is being 264written from the user-supplied buffer to the device. 265.It Dv CAM_DIR_NONE 266This indicates that there is no data to be transferred for this command. 267.It Dv CAM_DEV_QFRZDIS 268This flag disables device queue freezing as an error recovery mechanism. 269.It Dv CAM_PASS_ERR_RECOVER 270This flag tells the 271.Xr pass 4 272driver to enable error recovery. The default is to not perform error 273recovery, which means that the retry count won't be honored without this 274flag, among other things. 275.It Dv CAM_DATA_PHYS 276This indicates that the address contained in 277.Fa data_ptr 278is a physical address, not a virtual address. 279.El 280.Pp 281The 282.Fa retry_count 283tells the kernel how many times to retry the command in question. The 284retry count is ignored unless the 285.Xr pass 4 286driver is told to enable error recovery via the 287.Dv CAM_PASS_ERR_RECOVER 288flag. 289.Pp 290The 291.Fa timeout 292tells the kernel how long to wait for the given command to complete. If 293the timeout expires and the command hasn't completed, the CCB will be 294returned from the kernel with an appropriate error status. 295.Pp 296.Fa cmd_spec 297is a CDB format specifier used to build up the SCSI CDB. 298This text string is made up of a list of field specifiers. Field 299specifiers specify the value for each CDB field (including indicating 300that the value be taken from the next argument in the 301variable argument list), the width 302of the field in bits or bytes, and an optional name. White space is 303ignored, and the pound sign ('#') introduces a comment that ends at the 304end of the current line. 305.Pp 306The optional name is the first part of a field specifier and 307is in curly braces. The text in curly braces in this example are 308the names: 309.Dl "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page" 310.Pp 311This field specifier has two one bit fields and one six bit field. 312The second one bit field is the constant value 0 and the first 313one bit field and the six bit field are taken from the variable 314argument list. 315Multi byte fields are swapped into the SCSI byte order in the 316CDB and white space is ignored. 317.Pp 318When the field is a hex value or the letter v, (e.g., 319.Fa "1A" 320or 321.Fa "v" ) 322then a single byte value 323is copied to the next unused byte of the CDB. 324When the letter 325.Fa v 326is used the next integer argument is taken from the variable argument list 327and that value used. 328.Pp 329A constant hex value followed by a field width specifier or the letter 330.Fa v 331followed by a field width specifier (e.g., 332.Fa 3:4 , 333.Fa 3:b4 , 334.Fa 3:i3 , 335.Fa v:i3 ) 336specifies a field of a given bit or byte width. 337Either the constant value or (for the V specifier) the next integer value from 338the variable argument list is copied to the next unused 339bits or bytes of the CDB. 340.Pp 341A decimal number or the letter 342.Fa b 343followed by a decimal number field width indicates a bit field of that width. 344The bit fields are packed as tightly as possible beginning with the 345high bit (so that it reads the same as the SCSI spec), and a new byte of 346the CDB is started whenever a byte fills completely or when an 347.Fa i 348field is encountered. 349.Pp 350A field width specifier consisting of the letter 351.Fa i 352followed by either 3531, 2, 3 or 4 indicates a 1, 2, 3 or 4 byte integral value that must 354be swapped into SCSI byte order (MSB first). 355.Pp 356For the 357.Fa v 358field specifier the next integer argument is taken from the variable argument 359list and that value is used swapped into SCSI byte order. 360.Pp 361.Fn csio_build_visit 362operates similarly to 363.Fn csio_build , 364except that the values to substitute for variable arguments in 365.Fa cmd_spec 366are retrieved via the 367.Fn arg_get 368function passed in to 369.Fn csio_build_visit 370instead of via 371.Xr stdarg 3 . 372The 373.Fn arg_get 374function takes two arguments: 375.Bl -tag -width field_name 376.It Fa gethook 377is passed into the 378.Fn arg_get 379function at each invocation. This enables the 380.Fn arg_get 381function to keep some state in between calls without using global or static 382variables. 383.It Fa field_name 384is the field name supplied in 385.Fa fmt , 386if any. 387.El 388.Pp 389.Fn csio_decode 390is used to decode information from the data in phase of the SCSI 391transfer. 392.Pp 393The decoding is similar to 394the command specifier processing of 395.Fn csio_build 396except that the data is extracted from the data pointed to by 397.Fa csio->data_ptr . 398The stdarg list should be pointers to integers instead of integer 399values. 400A seek field type and a suppression modifier are added. 401The 402.Fa * 403suppression modifier (e.g., 404.Fa *i3 405or 406.Fa *b4 ) 407suppresses assignment from the field and can be used to skip 408over bytes or bits in the data, without having to copy 409them to a dummy variable in the arg list. 410.Pp 411The seek field type 412.Fa s 413permits you to skip over data. 414This seeks to an absolute position 415.Pq Fa s3 416or a relative position 417.Pq Fa s+3 418in the data, based on whether or not the presence of the '+' sign. 419The seek value can be specified as 420.Fa v 421and the next integer value from the argument list will be 422used as the seek value. 423.Pp 424.Fn csio_decode_visit 425operates like 426.Fn csio_decode 427except that instead of placing the decoded contents of the buffer in 428variadic arguments, the decoded buffer contents are returned to the user 429via the 430.Fn arg_put 431function that is passed in. 432The 433.Fn arg_put 434function takes several arguments: 435.Bl -tag -width letter 436.It Fa hook 437The "hook" is a mechanism to allow the 438.Fn arg_put 439function to save state in between calls. 440.It Fa letter 441is the letter describing the format of the argument being passed into the 442function. 443.It Fa val 444is a void pointer to the value being passed into the function. 445.It Fa count 446is the size of the value being passed into the 447.Fn arg_put 448function. The argument format determines the unit of measure. 449.It Fa name 450This is a text description of the field, if one was provided in the 451.Fa fmt . 452.El 453.Pp 454.Fn buff_decode 455decodes an arbitrary data buffer using the method 456described above for 457.Fn csio_decode . 458.Pp 459.Fn buff_decode_visit 460decodes an arbitrary data buffer using the method described above for 461.Fn csio_decode_visit . 462.Pp 463.Fn csio_encode 464encodes the 465.Fa data_ptr 466portion (not the CDB!) of a 467.Va ccb_scsiio 468structure, using the method described above for 469.Fn csio_build . 470.Pp 471.Fn csio_encode_visit 472encodes the 473.Fa data_ptr 474portion (not the CDB!) of a 475.Va ccb_scsiio 476structure, using the method described above for 477.Fn csio_build_visit . 478.Pp 479.Fn buff_encode_visit 480encodes an arbitrary data pointer, using the method described 481above for 482.Fn csio_build_visit . 483.Sh RETURN VALUES 484.Fn csio_build , 485.Fn csio_build_visit , 486.Fn csio_encode , 487.Fn csio_encode_visit , 488and 489.Fn buff_encode_visit 490return the number of fields processed. 491.Pp 492.Fn csio_decode , 493.Fn csio_decode_visit , 494.Fn buff_decode , 495and 496.Fn buff_decode_visit 497return the number of assignments performed. 498.Sh SEE ALSO 499.Xr cam 3 , 500.Xr pass 4 , 501.Xr camcontrol 8 502.Sh HISTORY 503The CAM versions of these functions are based upon similar functions 504implemented for the old 505.Fx 506.Tn SCSI 507layer. The encoding/decoding functions in the old 508.Tn SCSI 509code were written by Peter Dufault. 510.Pp 511Many systems have comparable interfaces to permit a user to construct a 512SCSI command in user space. 513.Pp 514The old 515.Va scsireq 516data structure was almost identical to the SGI /dev/scsi data 517structure. If anyone knows the name of the authors it should 518go here; Peter Dufault first read about it in a 1989 Sun Expert magazine. 519.Pp 520The new CCB data structures are derived from the CAM-2 and CAM-3 521specifications. 522.Pp 523.An Peter Dufault 524implemented a clone of SGI's interface in 525.Bx 386 526that 527led to the original 528.Fx 529.Tn SCSI 530library and the related kernel ioctl. 531If anyone needs that for compatibility contact dufault@hda.com. 532.Sh AUTHORS 533.An -nosplit 534.An Kenneth Merry 535implemented the CAM versions of these encoding and decoding functions. 536This current work is based upon earlier work by 537.An Peter Dufault . 538.Sh BUGS 539There should probably be a function that encodes both the CDB and the data 540buffer portions of a 541.Tn SCSI 542CCB. I discovered this while implementing the arbitrary command execution 543code in 544.Xr camcontrol 8 , 545but I haven't yet had time to implement such a function. 546.Pp 547Some of the CCB flag descriptions really don't belong here. Rather they 548belong in a generic CCB man page. Since that man page hasn't yet been 549written, the shorter descriptions here will have to suffice. 550