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 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.In stdio.h 82.In 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 "const 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 "const 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 "const char *fmt" 110.Fa "..." 111.Fc 112.Ft int 113.Fo csio_decode_visit 114.Fa "struct ccb_scsiio *csio" 115.Fa "const 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 "const 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 "const 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 "const char *fmt" 142.Fa "..." 143.Fc 144.Ft int 145.Fo csio_encode_visit 146.Fa "struct ccb_scsiio *csio" 147.Fa "const 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 "const 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 166.Fx 167.Tn SCSI 168layer. 169.Pp 170These functions may be used in new applications, but users may find it 171easier to use the various SCSI CCB building functions included with the 172.Xr cam 3 173library. 174(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. 199If no data is to be 200transferred for the 201.Tn SCSI 202command in question, this should be set to NULL. 203If there is data to 204transfer for the command, this buffer must be at least 205.Fa dxfer_len 206long. 207.Pp 208.Fa flags 209are the flags defined in 210.In cam/cam_ccb.h : 211.Bd -literal 212/* Common CCB header */ 213/* CAM CCB flags */ 214typedef enum { 215 CAM_CDB_POINTER = 0x00000001,/* The CDB field is a pointer */ 216 CAM_QUEUE_ENABLE = 0x00000002,/* SIM queue actions are enabled */ 217 CAM_CDB_LINKED = 0x00000004,/* CCB contains a linked CDB */ 218 CAM_SCATTER_VALID = 0x00000010,/* Scatter/gather list is valid */ 219 CAM_DIS_AUTOSENSE = 0x00000020,/* Disable autosense feature */ 220 CAM_DIR_RESV = 0x00000000,/* Data direction (00:reserved) */ 221 CAM_DIR_IN = 0x00000040,/* Data direction (01:DATA IN) */ 222 CAM_DIR_OUT = 0x00000080,/* Data direction (10:DATA OUT) */ 223 CAM_DIR_NONE = 0x000000C0,/* Data direction (11:no data) */ 224 CAM_DIR_MASK = 0x000000C0,/* Data direction Mask */ 225 CAM_SOFT_RST_OP = 0x00000100,/* Use Soft reset alternative */ 226 CAM_ENG_SYNC = 0x00000200,/* Flush resid bytes on complete */ 227 CAM_DEV_QFRZDIS = 0x00000400,/* Disable DEV Q freezing */ 228 CAM_DEV_QFREEZE = 0x00000800,/* Freeze DEV Q on execution */ 229 CAM_HIGH_POWER = 0x00001000,/* Command takes a lot of power */ 230 CAM_SENSE_PTR = 0x00002000,/* Sense data is a pointer */ 231 CAM_SENSE_PHYS = 0x00004000,/* Sense pointer is physical addr*/ 232 CAM_TAG_ACTION_VALID = 0x00008000,/* Use the tag action in this ccb*/ 233 CAM_PASS_ERR_RECOVER = 0x00010000,/* Pass driver does err. recovery*/ 234 CAM_DIS_DISCONNECT = 0x00020000,/* Disable disconnect */ 235 CAM_SG_LIST_PHYS = 0x00040000,/* SG list has physical addrs. */ 236 CAM_MSG_BUF_PHYS = 0x00080000,/* Message buffer ptr is physical*/ 237 CAM_SNS_BUF_PHYS = 0x00100000,/* Autosense data ptr is physical*/ 238 CAM_DATA_PHYS = 0x00200000,/* SG/Buffer data ptrs are phys. */ 239 CAM_CDB_PHYS = 0x00400000,/* CDB pointer is physical */ 240 CAM_ENG_SGLIST = 0x00800000,/* SG list is for the HBA engine */ 241 242/* Phase cognizant mode flags */ 243 CAM_DIS_AUTOSRP = 0x01000000,/* Disable autosave/restore ptrs */ 244 CAM_DIS_AUTODISC = 0x02000000,/* Disable auto disconnect */ 245 CAM_TGT_CCB_AVAIL = 0x04000000,/* Target CCB available */ 246 CAM_TGT_PHASE_MODE = 0x08000000,/* The SIM runs in phase mode */ 247 CAM_MSGB_VALID = 0x20000000,/* Message buffer valid */ 248 CAM_STATUS_VALID = 0x40000000,/* Status buffer valid */ 249 CAM_DATAB_VALID = 0x80000000,/* Data buffer valid */ 250 251/* Host target Mode flags */ 252 CAM_TERM_IO = 0x20000000,/* Terminate I/O Message sup. */ 253 CAM_DISCONNECT = 0x40000000,/* Disconnects are mandatory */ 254 CAM_SEND_STATUS = 0x80000000,/* Send status after data phase */ 255} ccb_flags; 256.Ed 257.Pp 258Multiple flags should be ORed together. 259Any of the CCB flags may be used, 260although it is worth noting several important ones here: 261.Pp 262.Bl -tag -width CAM_PASS_ERR_RECOVER 263.It Dv CAM_DIR_IN 264This indicates that the operation in question is a read operation. 265i.e., 266data is being read from the 267.Tn SCSI 268device to the user-supplied buffer. 269.It Dv CAM_DIR_OUT 270This indicates that the operation is a write operation. 271i.e., data is being 272written from the user-supplied buffer to the device. 273.It Dv CAM_DIR_NONE 274This indicates that there is no data to be transferred for this command. 275.It Dv CAM_DEV_QFRZDIS 276This flag disables device queue freezing as an error recovery mechanism. 277.It Dv CAM_PASS_ERR_RECOVER 278This flag tells the 279.Xr pass 4 280driver to enable error recovery. 281The default is to not perform error 282recovery, which means that the retry count will not be honored without this 283flag, among other things. 284.It Dv CAM_DATA_PHYS 285This indicates that the address contained in 286.Fa data_ptr 287is a physical address, not a virtual address. 288.El 289.Pp 290The 291.Fa retry_count 292tells the kernel how many times to retry the command in question. 293The 294retry count is ignored unless the 295.Xr pass 4 296driver is told to enable error recovery via the 297.Dv CAM_PASS_ERR_RECOVER 298flag. 299.Pp 300The 301.Fa timeout 302tells the kernel how long to wait for the given command to complete. 303If 304the timeout expires and the command has not completed, the CCB will be 305returned from the kernel with an appropriate error status. 306.Pp 307.Fa cmd_spec 308is a CDB format specifier used to build up the SCSI CDB. 309This text string is made up of a list of field specifiers. 310Field 311specifiers specify the value for each CDB field (including indicating 312that the value be taken from the next argument in the 313variable argument list), the width 314of the field in bits or bytes, and an optional name. 315White space is 316ignored, and the pound sign ('#') introduces a comment that ends at the 317end of the current line. 318.Pp 319The optional name is the first part of a field specifier and 320is in curly braces. 321The text in curly braces in this example are 322the names: 323.Dl "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page" 324.Pp 325This field specifier has two one bit fields and one six bit field. 326The second one bit field is the constant value 0 and the first 327one bit field and the six bit field are taken from the variable 328argument list. 329Multi byte fields are swapped into the SCSI byte order in the 330CDB and white space is ignored. 331.Pp 332When the field is a hex value or the letter v, (e.g., 333.Fa "1A" 334or 335.Fa "v" ) 336then a single byte value 337is copied to the next unused byte of the CDB. 338When the letter 339.Fa v 340is used the next integer argument is taken from the variable argument list 341and that value used. 342.Pp 343A constant hex value followed by a field width specifier or the letter 344.Fa v 345followed by a field width specifier (e.g., 346.Fa 3:4 , 347.Fa 3:b4 , 348.Fa 3:i3 , 349.Fa v:i3 ) 350specifies a field of a given bit or byte width. 351Either the constant value or (for the V specifier) the next integer value from 352the variable argument list is copied to the next unused 353bits or bytes of the CDB. 354.Pp 355A decimal number or the letter 356.Fa b 357followed by a decimal number field width indicates a bit field of that width. 358The bit fields are packed as tightly as possible beginning with the 359high bit (so that it reads the same as the SCSI spec), and a new byte of 360the CDB is started whenever a byte fills completely or when an 361.Fa i 362field is encountered. 363.Pp 364A field width specifier consisting of the letter 365.Fa i 366followed by either 3671, 2, 3 or 4 indicates a 1, 2, 3 or 4 byte integral value that must 368be swapped into SCSI byte order (MSB first). 369.Pp 370For the 371.Fa v 372field specifier the next integer argument is taken from the variable argument 373list and that value is used swapped into SCSI byte order. 374.Pp 375.Fn csio_build_visit 376operates similarly to 377.Fn csio_build , 378except that the values to substitute for variable arguments in 379.Fa cmd_spec 380are retrieved via the 381.Fn arg_get 382function passed in to 383.Fn csio_build_visit 384instead of via 385.Xr stdarg 3 . 386The 387.Fn arg_get 388function takes two arguments: 389.Bl -tag -width field_name 390.It Fa gethook 391is passed into the 392.Fn arg_get 393function at each invocation. 394This enables the 395.Fn arg_get 396function to keep some state in between calls without using global or static 397variables. 398.It Fa field_name 399is the field name supplied in 400.Fa fmt , 401if any. 402.El 403.Pp 404.Fn csio_decode 405is used to decode information from the data in phase of the SCSI 406transfer. 407.Pp 408The decoding is similar to 409the command specifier processing of 410.Fn csio_build 411except that the data is extracted from the data pointed to by 412.Fa csio->data_ptr . 413The stdarg list should be pointers to integers instead of integer 414values. 415A seek field type and a suppression modifier are added. 416The 417.Fa * 418suppression modifier (e.g., 419.Fa *i3 420or 421.Fa *b4 ) 422suppresses assignment from the field and can be used to skip 423over bytes or bits in the data, without having to copy 424them to a dummy variable in the arg list. 425.Pp 426The seek field type 427.Fa s 428permits you to skip over data. 429This seeks to an absolute position 430.Pq Fa s3 431or a relative position 432.Pq Fa s+3 433in the data, based on whether or not the presence of the '+' sign. 434The seek value can be specified as 435.Fa v 436and the next integer value from the argument list will be 437used as the seek value. 438.Pp 439.Fn csio_decode_visit 440operates like 441.Fn csio_decode 442except that instead of placing the decoded contents of the buffer in 443variadic arguments, the decoded buffer contents are returned to the user 444via the 445.Fn arg_put 446function that is passed in. 447The 448.Fn arg_put 449function takes several arguments: 450.Bl -tag -width letter 451.It Fa hook 452The "hook" is a mechanism to allow the 453.Fn arg_put 454function to save state in between calls. 455.It Fa letter 456is the letter describing the format of the argument being passed into the 457function. 458.It Fa val 459is a void pointer to the value being passed into the function. 460.It Fa count 461is the size of the value being passed into the 462.Fn arg_put 463function. 464The argument format determines the unit of measure. 465.It Fa name 466This is a text description of the field, if one was provided in the 467.Fa fmt . 468.El 469.Pp 470.Fn buff_decode 471decodes an arbitrary data buffer using the method 472described above for 473.Fn csio_decode . 474.Pp 475.Fn buff_decode_visit 476decodes an arbitrary data buffer using the method described above for 477.Fn csio_decode_visit . 478.Pp 479.Fn csio_encode 480encodes the 481.Fa data_ptr 482portion (not the CDB!) of a 483.Va ccb_scsiio 484structure, using the method described above for 485.Fn csio_build . 486.Pp 487.Fn csio_encode_visit 488encodes the 489.Fa data_ptr 490portion (not the CDB!) of a 491.Va ccb_scsiio 492structure, using the method described above for 493.Fn csio_build_visit . 494.Pp 495.Fn buff_encode_visit 496encodes an arbitrary data pointer, using the method described 497above for 498.Fn csio_build_visit . 499.Sh RETURN VALUES 500.Fn csio_build , 501.Fn csio_build_visit , 502.Fn csio_encode , 503.Fn csio_encode_visit , 504and 505.Fn buff_encode_visit 506return the number of fields processed. 507.Pp 508.Fn csio_decode , 509.Fn csio_decode_visit , 510.Fn buff_decode , 511and 512.Fn buff_decode_visit 513return the number of assignments performed. 514.Sh SEE ALSO 515.Xr cam 3 , 516.Xr pass 4 , 517.Xr camcontrol 8 518.Sh HISTORY 519The CAM versions of these functions are based upon similar functions 520implemented for the old 521.Fx 522.Tn SCSI 523layer. 524The encoding/decoding functions in the old 525.Tn SCSI 526code were written by Peter Dufault. 527.Pp 528Many systems have comparable interfaces to permit a user to construct a 529SCSI command in user space. 530.Pp 531The old 532.Va scsireq 533data structure was almost identical to the SGI /dev/scsi data 534structure. 535If anyone knows the name of the authors it should 536go here; Peter Dufault first read about it in a 1989 Sun Expert magazine. 537.Pp 538The new CCB data structures are derived from the CAM-2 and CAM-3 539specifications. 540.Pp 541.An Peter Dufault 542implemented a clone of SGI's interface in 543.Bx 386 544that 545led to the original 546.Fx 547.Tn SCSI 548library and the related kernel ioctl. 549If anyone needs that for compatibility contact dufault@hda.com. 550.Sh AUTHORS 551Kenneth Merry implemented the CAM versions of these encoding and decoding 552functions. 553This current work is based upon earlier work by Peter Dufault. 554.Sh BUGS 555There should probably be a function that encodes both the CDB and the data 556buffer portions of a 557.Tn SCSI 558CCB. 559I discovered this while implementing the arbitrary command execution 560code in 561.Xr camcontrol 8 , 562but I have not yet had time to implement such a function. 563.Pp 564Some of the CCB flag descriptions really do not belong here. 565Rather they 566belong in a generic CCB man page. 567Since that man page has not yet been 568written, the shorter descriptions here will have to suffice. 569