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.\" $FreeBSD$ 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 LIBRARY 79.Lb libcam 80.Sh SYNOPSIS 81.Fd #include <stdio.h> 82.Fd #include <camlib.h> 83.Ft int 84.Fo csio_build 85.Fa "struct ccb_scsiio *csio" 86.Fa "u_int8_t *data_ptr" 87.Fa "u_int32_t dxfer_len" 88.Fa "u_int32_t flags" 89.Fa "int retry_count" 90.Fa "int timeout" 91.Fa "char *cmd_spec" 92.Fa "..." 93.Fc 94.Ft int 95.Fo csio_build_visit 96.Fa "struct ccb_scsiio *csio" 97.Fa "u_int8_t *data_ptr" 98.Fa "u_int32_t dxfer_len" 99.Fa "u_int32_t flags" 100.Fa "int retry_count" 101.Fa "int timeout" 102.Fa "char *cmd_spec" 103.Fa "int (*arg_get)(void *hook, char *field_name)" 104.Fa "void *gethook" 105.Fc 106.Ft int 107.Fo csio_decode 108.Fa "struct ccb_scsiio *csio" 109.Fa "char *fmt" 110.Fa "..." 111.Fc 112.Ft int 113.Fo csio_decode_visit 114.Fa "struct ccb_scsiio *csio" 115.Fa "char *fmt" 116.Fa "void (*arg_put)(void *hook" 117.Fa "int letter" 118.Fa "void *val" 119.Fa "int count" 120.Fa "char *name)" 121.Fa "void *puthook" 122.Fc 123.Ft int 124.Fo buff_decode 125.Fa "u_int8_t *buff" 126.Fa "size_t len" 127.Fa "char *fmt" 128.Fa "..." 129.Fc 130.Ft int 131.Fo buff_decode_visit 132.Fa "u_int8_t *buff" 133.Fa "size_t len" 134.Fa "char *fmt" 135.Fa "void (*arg_put)(void *, int, void *, int, char *)" 136.Fa "void *puthook" 137.Fc 138.Ft int 139.Fo csio_encode 140.Fa "struct ccb_scsiio *csio" 141.Fa "char *fmt" 142.Fa "..." 143.Fc 144.Ft int 145.Fo csio_encode_visit 146.Fa "struct ccb_scsiio *csio" 147.Fa "char *fmt" 148.Fa "int (*arg_get)(void *hook, char *field_name)" 149.Fa "void *gethook" 150.Fc 151.Ft int 152.Fo buff_encode_visit 153.Fa "u_int8_t *buff" 154.Fa "size_t len" 155.Fa "char *fmt" 156.Fa "int (*arg_get)(void *hook, char *field_name)" 157.Fa "void *gethook" 158.Fc 159.Sh DESCRIPTION 160The CAM buffer/CDB encoding and decoding routines provide a relatively easy 161migration path for userland 162.Tn SCSI 163applications written with the similarly-named 164.Va scsireq_ Ns * 165functions from the old FreeBSD 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.Aq Pa 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 poiner 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,/* Diable 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.Pp 257.Bl -tag -width CAM_PASS_ERR_RECOVER 258.It Dv CAM_DIR_IN 259This indicates that the operation in question is a read operation. i.e., 260data is being read from the 261.Tn SCSI 262device to the user-supplied buffer. 263.It Dv CAM_DIR_OUT 264This indicates that the operation is a write operation. i.e. data is being 265written from the user-supplied buffer to the device. 266.It Dv CAM_DIR_NONE 267This indicates that there is no data to be transferred for this command. 268.It Dv CAM_DEV_QFRZDIS 269This flag disables device queue freezing as an error recovery mechanism. 270.It Dv CAM_PASS_ERR_RECOVER 271This flag tells the 272.Xr pass 4 273driver to enable error recovery. The default is to not perform error 274recovery, which means that the retry count won't be honored without this 275flag, among other things. 276.It Dv CAM_DATA_PHYS 277This indicates that the address contained in 278.Fa data_ptr 279is a physical address, not a virtual address. 280.El 281.Pp 282The 283.Fa retry_count 284tells the kernel how many times to retry the command in question. The 285retry count is ignored unless the 286.Xr pass 4 287driver is told to enable error recovery via the 288.Dv CAM_PASS_ERR_RECOVER 289flag. 290.Pp 291The 292.Fa timeout 293tells the kernel how long to wait for the given command to complete. If 294the timeout expires and the command hasn't completed, the CCB will be 295returned from the kernel with an appropriate error status. 296.Pp 297.Fa cmd_spec 298is a CDB format specifier used to build up the SCSI CDB. 299This text string is made up of a list of field specifiers. Field 300specifiers specify the value for each CDB field (including indicating 301that the value be taken from the next argument in the 302variable argument list), the width 303of the field in bits or bytes, and an optional name. White space is 304ignored, and the pound sign ('#') introduces a comment that ends at the 305end of the current line. 306.Pp 307The optional name is the first part of a field specifier and 308is in curly braces. The text in curly braces in this example are 309the names: 310.Dl "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page" 311.Pp 312This field specifier has two one bit fields and one six bit field. 313The second one bit field is the constant value 0 and the first 314one bit field and the six bit field are taken from the variable 315argument list. 316Multi byte fields are swapped into the SCSI byte order in the 317CDB and white space is ignored. 318.Pp 319When the field is a hex value or the letter v, (e.g., 320.Fa "1A" 321or 322.Fa "v" ) 323then a single byte value 324is copied to the next unused byte of the CDB. 325When the letter 326.Fa v 327is used the next integer argument is taken from the variable argument list 328and that value used. 329.Pp 330A constant hex value followed by a field width specifier or the letter 331.Fa v 332followed by a field width specifier (e.g., 333.Fa 3:4 , 334.Fa 3:b4 , 335.Fa 3:i3 , 336.FR v:i3 ) 337specifies a field of a given bit or byte width. 338Either the constant value or (for the V specifier) the next integer value from 339the variable argument list is copied to the next unused 340bits or bytes of the CDB. 341.Pp 342A decimal number or the letter 343.Fa b 344followed by a decimal number field width indicates a bit field of that width. 345The bit fields are packed as tightly as possible beginning with the 346high bit (so that it reads the same as the SCSI spec), and a new byte of 347the CDB is started whenever a byte fills completely or when an 348.Fa i 349field is encountered. 350.Pp 351A field width specifier consisting of the letter 352.Fa i 353followed by either 3541, 2, 3 or 4 indicates a 1, 2, 3 or 4 byte integral value that must 355be swapped into SCSI byte order (MSB first). 356.Pp 357For the 358.Fa v 359field specifier the next integer argument is taken from the variable argument 360list and that value is used swapped into SCSI byte order. 361.Pp 362.Fn csio_build_visit 363operates similarly to 364.Fn csio_build , 365except that the values to substitute for variable arguments in 366.Fa cmd_spec 367are retrieved via the 368.Fn arg_get 369function passed in to 370.Fn csio_build_visit 371instead of via 372.Xr stdarg 3 . 373The 374.Fn arg_get 375function takes two arguments: 376.Bl -tag -width field_name 377.It Fa gethook 378is passed into the 379.Fn arg_get 380function at each invocation. This enables the 381.Fn arg_get 382function to keep some state in between calls without using global or static 383variables. 384.It Fa field_name 385is the field name supplied in 386.Fa fmt , 387if any. 388.El 389.Pp 390.Fn csio_decode 391is used to decode information from the data in phase of the SCSI 392transfer. 393.Pp 394The decoding is similar to 395the command specifier processing of 396.Fn csio_build 397except that the data is extracted from the data pointed to by 398.Fa csio->data_ptr . 399The stdarg list should be pointers to integers instead of integer 400values. 401A seek field type and a suppression modifier are added. 402The 403.Fa * 404suppression modifier (e.g., 405.Fa *i3 406or 407.Fa *b4 ) 408suppresses assignment from the field and can be used to skip 409over bytes or bits in the data, without having to copy 410them to a dummy variable in the arg list. 411.Pp 412The seek field type 413.Fa s 414permits you to skip over data. 415This seeks to an absolute position ( 416.Fa s3 ) 417or a relative position ( 418.Fa s+3 ) 419in the data, based on whether or not the presence of the '+' sign. 420The seek value can be specified as 421.Fa v 422and the next integer value from the argument list will be 423used as the seek value. 424.Pp 425.Fn csio_decode_visit 426operates like 427.Fn csio_decode 428except that instead of placing the decoded contents of the buffer in 429varardic arguments, the decoded buffer contents are returned to the user 430via the 431.Fn arg_put 432function that is passed in. 433The 434.Fn arg_put 435function takes several arguments: 436.Bl -tag -width letter 437.It Fa hook 438The "hook" is a mechanism to allow the 439.Fn arg_put 440function to save state in between calls. 441.It Fa letter 442is the letter describing the format of the argument being passed into the 443function. 444.It Fa val 445is a void pointer to the value being passed into the function. 446.It Fa count 447is the number of arguments being passed into the 448.Fn arg_put 449function. At present this will only be set to 1. 450.It Fa name 451This is a text description of the field, if one was provided in the 452.Fa fmt . 453.El 454.Pp 455.Fn buff_decode 456decodes an arbitrary data buffer using the method 457described above for 458.Fn csio_decode . 459.Pp 460.Fn buff_decode_visit 461decodes an arbitrary data buffer using the method described above for 462.Fn csio_decode_visit . 463.Pp 464.Fn csio_encode 465encodes the 466.Fa data_ptr 467portion (not the CDB!) of a 468.Va ccb_scsiio 469structure, using the method described above for 470.Fn csio_build . 471.Pp 472.Fn csio_encode_visit 473encodes the 474.Fa data_ptr 475portion (not the CDB!) of a 476.Va ccb_scsiio 477structure, using the method described above for 478.Fn csio_build_visit . 479.Pp 480.Fn buff_encode_visit 481encodes an arbitrary data pointer, using the method described 482above for 483.Fn csio_build_visit . 484.Sh RETURN VALUES 485.Fn csio_build , 486.Fn csio_build_visit , 487.Fn csio_encode , 488.Fn csio_encode_visit , 489and 490.Fn buff_encode_visit 491return the number of fields processed. 492.Pp 493.Fn csio_decode , 494.Fn csio_decode_visit , 495.Fn buff_decode , 496and 497.Fn buff_decode_visit 498return the number of assignments performed. 499.Sh SEE ALSO 500.Xr cam 3 , 501.Xr pass 4 , 502.Xr camcontrol 8 503.Sh HISTORY 504.Pp 505The CAM versions of these functions are based upon similar functions 506implemented for the old FreeBSD 507.Tn SCSI 508layer. The encoding/decoding functions in the old 509.Tn SCSI 510code were written by Peter Dufault. 511.Pp 512Many systems have comparable interfaces to permit a user to construct a 513SCSI command in user space. 514.Pp 515The old 516.Va scsireq 517data structure was almost identical to the SGI /dev/scsi data 518structure. If anyone knows the name of the authors it should 519go here; Peter Dufault first read about it in a 1989 Sun Expert magazine. 520.Pp 521The new CCB data structures are derived from the CAM-2 and CAM-3 522specifications. 523.Pp 524Peter Dufault implemented a clone of SGI's interface in 386bsd that 525led to the original FreeBSD 526.Tn SCSI 527library and the related kernel ioctl. 528If anyone needs that for compatibility contact dufault@hda.com. 529.Sh AUTHORS 530Kenneth Merry implemented the CAM versions of these encoding and decoding 531functions. This current work is based upon earlier work by Peter Dufault. 532.Sh BUGS 533There should probably be a function that encodes both the CDB and the data 534buffer portions of a 535.Tn SCSI 536CCB. I discovered this while implementing the arbitrary command execution 537code in 538.Xr camcontrol 8 , 539but I haven't yet had time to implement such a function. 540.Pp 541Some of the CCB flag descriptions really don't belong here. Rather they 542belong in a generic CCB man page. Since that man page hasn't yet been 543written, the shorter descriptions here will have to suffice. 544