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.\" $Id$ 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.\" 64.Dd October 13, 1998 65.Os FreeBSD 3.0 66.Dt CAM_CDBPARSE 3 67.Sh NAME 68.Nm csio_build , 69.Nm csio_build_visit , 70.Nm csio_decode , 71.Nm csio_decode_visit , 72.Nm buff_decode , 73.Nm buff_decode_visit , 74.Nm csio_encode , 75.Nm csio_encode_visit , 76.Nm buff_encode_visit 77.Nd CAM user library SCSI buffer parsing routines 78.Sh SYNOPSIS 79.Fd #include <camlib.h> 80.Ft int 81.Fo csio_build 82.Fa "struct ccb_scsiio *csio" 83.Fa "u_int8_t *data_ptr" 84.Fa "u_int32_t dxfer_len" 85.Fa "u_int32_t flags" 86.Fa "int retry_count" 87.Fa "int timeout" 88.Fa "char *cmd_spec" 89.Fa "..." 90.Fc 91.Ft int 92.Fo csio_build_visit 93.Fa "struct ccb_scsiio *csio" 94.Fa "u_int8_t *data_ptr" 95.Fa "u_int32_t dxfer_len" 96.Fa "u_int32_t flags" 97.Fa "int retry_count" 98.Fa "int timeout" 99.Fa "char *cmd_spec" 100.Fa "int (*arg_get)(void *hook, char *field_name)" 101.Fa "void *gethook" 102.Fc 103.Ft int 104.Fo csio_decode 105.Fa "struct ccb_scsiio *csio" 106.Fa "char *fmt" 107.Fa "..." 108.Fc 109.Ft int 110.Fo csio_decode_visit 111.Fa "struct ccb_scsiio *csio" 112.Fa "char *fmt" 113.Fa "void (*arg_put)(void *hook" 114.Fa "int letter" 115.Fa "void *val" 116.Fa "int count" 117.Fa "char *name)" 118.Fa "void *puthook" 119.Fc 120.Ft int 121.Fo buff_decode 122.Fa "u_int8_t *buff" 123.Fa "size_t len" 124.Fa "char *fmt" 125.Fa "..." 126.Fc 127.Ft int 128.Fo buff_decode_visit 129.Fa "u_int8_t *buff" 130.Fa "size_t len" 131.Fa "char *fmt" 132.Fa "void (*arg_put)(void *, int, void *, int, char *)" 133.Fa "void *puthook" 134.Fc 135.Ft int 136.Fo csio_encode 137.Fa "struct ccb_scsiio *csio" 138.Fa "char *fmt" 139.Fa "..." 140.Fc 141.Ft int 142.Fo csio_encode_visit 143.Fa "struct ccb_scsiio *csio" 144.Fa "char *fmt" 145.Fa "int (*arg_get)(void *hook, char *field_name)" 146.Fa "void *gethook" 147.Fc 148.Ft int 149.Fo buff_encode_visit 150.Fa "u_int8_t *buff" 151.Fa "size_t len" 152.Fa "char *fmt" 153.Fa "int (*arg_get)(void *hook, char *field_name)" 154.Fa "void *gethook" 155.Fc 156.Sh DESCRIPTION 157The CAM buffer/CDB encoding and decoding routines provide a relatively easy 158migration path for userland 159.Tn SCSI 160applications written with the similarly-named 161.Va scsireq_ Ns * 162functions from the old FreeBSD 163.Tn SCSI 164layer. 165.Pp 166These functions may be used in new applications, but users may find it 167easier to use the various SCSI CCB building functions included with the 168.Xr cam 3 169library. (e.g. 170.Fn cam_fill_csio , 171.Fn scsi_start_stop , 172and 173.Fn scsi_read_write ) 174.Pp 175.Fn csio_build 176builds up a 177.Va ccb_scsiio 178structure based on the information provided in 179the variable argument list. 180It gracefully handles a NULL 181.Fa data_ptr 182argument passed to it. 183.Pp 184.Fa dxfer_len 185is the length of the data phase; the data transfer direction is 186determined by the 187.Fa flags 188argument. 189.Pp 190.Fa data_ptr 191is the data buffer used during the 192.Tn SCSI 193data phase. If no data is to be 194transferred for the 195.Tn SCSI 196command in question, this should be set to NULL. If there is data to 197transfer for the command, this buffer must be at least 198.Fa dxfer_len 199long. 200.Pp 201.Fa flags 202are the flags defined in 203.Aq Pa cam/cam_ccb.h : 204.Bd -literal 205/* Common CCB header */ 206/* CAM CCB flags */ 207typedef enum { 208 CAM_CDB_POINTER = 0x00000001,/* The CDB field is a pointer */ 209 CAM_QUEUE_ENABLE = 0x00000002,/* SIM queue actions are enabled */ 210 CAM_CDB_LINKED = 0x00000004,/* CCB contains a linked CDB */ 211 CAM_SCATTER_VALID = 0x00000010,/* Scatter/gather list is valid */ 212 CAM_DIS_AUTOSENSE = 0x00000020,/* Disable autosense feature */ 213 CAM_DIR_RESV = 0x00000000,/* Data direction (00:reserved) */ 214 CAM_DIR_IN = 0x00000040,/* Data direction (01:DATA IN) */ 215 CAM_DIR_OUT = 0x00000080,/* Data direction (10:DATA OUT) */ 216 CAM_DIR_NONE = 0x000000C0,/* Data direction (11:no data) */ 217 CAM_DIR_MASK = 0x000000C0,/* Data direction Mask */ 218 CAM_SOFT_RST_OP = 0x00000100,/* Use Soft reset alternative */ 219 CAM_ENG_SYNC = 0x00000200,/* Flush resid bytes on complete */ 220 CAM_DEV_QFRZDIS = 0x00000400,/* Disable DEV Q freezing */ 221 CAM_DEV_QFREEZE = 0x00000800,/* Freeze DEV Q on execution */ 222 CAM_HIGH_POWER = 0x00001000,/* Command takes a lot of power */ 223 CAM_SENSE_PTR = 0x00002000,/* Sense data is a pointer */ 224 CAM_SENSE_PHYS = 0x00004000,/* Sense pointer is physical addr*/ 225 CAM_TAG_ACTION_VALID = 0x00008000,/* Use the tag action in this ccb*/ 226 CAM_PASS_ERR_RECOVER = 0x00010000,/* Pass driver does err. recovery*/ 227 CAM_DIS_DISCONNECT = 0x00020000,/* Disable disconnect */ 228 CAM_SG_LIST_PHYS = 0x00040000,/* SG list has physical addrs. */ 229 CAM_MSG_BUF_PHYS = 0x00080000,/* Message buffer ptr is physical*/ 230 CAM_SNS_BUF_PHYS = 0x00100000,/* Autosense data ptr is physical*/ 231 CAM_DATA_PHYS = 0x00200000,/* SG/Buffer data ptrs are phys. */ 232 CAM_CDB_PHYS = 0x00400000,/* CDB poiner is physical */ 233 CAM_ENG_SGLIST = 0x00800000,/* SG list is for the HBA engine */ 234 235/* Phase cognizant mode flags */ 236 CAM_DIS_AUTOSRP = 0x01000000,/* Diable autosave/restore ptrs */ 237 CAM_DIS_AUTODISC = 0x02000000,/* Disable auto disconnect */ 238 CAM_TGT_CCB_AVAIL = 0x04000000,/* Target CCB available */ 239 CAM_TGT_PHASE_MODE = 0x08000000,/* The SIM runs in phase mode */ 240 CAM_MSGB_VALID = 0x20000000,/* Message buffer valid */ 241 CAM_STATUS_VALID = 0x40000000,/* Status buffer valid */ 242 CAM_DATAB_VALID = 0x80000000,/* Data buffer valid */ 243 244/* Host target Mode flags */ 245 CAM_TERM_IO = 0x20000000,/* Terminate I/O Message sup. */ 246 CAM_DISCONNECT = 0x40000000,/* Disconnects are mandatory */ 247 CAM_SEND_STATUS = 0x80000000,/* Send status after data phase */ 248} ccb_flags; 249.Ed 250.Pp 251Multiple flags should be ORed together. Any of the CCB flags may be used, 252although it is worth noting several important ones here: 253.Pp 254.Bl -tag -width CAM_PASS_ERR_RECOVER 255.It Dv CAM_DIR_IN 256This indicates that the operation in question is a read operation. i.e., 257data is being read from the 258.Tn SCSI 259device to the user-supplied buffer. 260.It Dv CAM_DIR_OUT 261This indicates that the operation is a write operation. i.e. data is being 262written from the user-supplied buffer to the device. 263.It Dv CAM_DIR_NONE 264This indicates that there is no data to be transferred for this command. 265.It Dv CAM_DEV_QFRZDIS 266This flag disables device queue freezing as an error recovery mechanism. 267.It Dv CAM_PASS_ERR_RECOVER 268This flag tells the 269.Xr pass 4 270driver to enable error recovery. The default is to not perform error 271recovery, which means that the retry count won't be honored without this 272flag, among other things. 273.It Dv CAM_DATA_PHYS 274This indicates that the address contained in 275.Fa data_ptr 276is a physical address, not a virtual address. 277.El 278.Pp 279The 280.Fa retry_count 281tells the kernel how many times to retry the command in question. The 282retry count is ignored unless the 283.Xr pass 4 284driver is told to enable error recovery via the 285.Dv CAM_PASS_ERR_RECOVER 286flag. 287.Pp 288The 289.Fa timeout 290tells the kernel how long to wait for the given command to complete. If 291the timeout expires and the command hasn't completed, the CCB will be 292returned from the kernel with an appropriate error status. 293.Pp 294.Fa cmd_spec 295is a CDB format specifier used to build up the SCSI CDB. 296This text string is made up of a list of field specifiers. Field 297specifiers specify the value for each CDB field (including indicating 298that the value be taken from the next argument in the 299variable argument list), the width 300of the field in bits or bytes, and an optional name. White space is 301ignored, and the pound sign ('#') introduces a comment that ends at the 302end of the current line. 303.Pp 304The optional name is the first part of a field specifier and 305is in curly braces. The text in curly braces in this example are 306the names: 307.Bd -literal -offset indent 308.Fa "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page" 309.Ed 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.FR 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.Fa s3 ) 416or a relative position ( 417.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 428varardic 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 number of arguments being passed into the 447.Fn arg_put 448function. At present this will only be set to 1. 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 503.Pp 504The CAM versions of these functions are based upon similar functions 505implemented for the old FreeBSD 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 523Peter Dufault implemented a clone of SGI's interface in 386bsd that 524led to the original FreeBSD 525.Tn SCSI 526library and the related kernel ioctl. 527If anyone needs that for compatibility contact dufault@hda.com. 528.Sh AUTHORS 529Kenneth Merry implemented the CAM versions of these encoding and decoding 530functions. This current work is based upon earlier work by Peter Dufault. 531.Sh BUGS 532There should probably be a function that encodes both the CDB and the data 533buffer portions of a 534.Tn SCSI 535CCB. I discovered this while implementing the arbitrary command execution 536code in 537.Xr camcontrol 8 , 538but I haven't yet had time to implement such a function. 539.Pp 540Some of the CCB flag descriptions really don't belong here. Rather they 541belong in a generic CCB man page. Since that man page hasn't yet been 542written, the shorter descriptions here will have to suffice. 543