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 March 13, 2017 65.Dt CAM_CDBPARSE 3 66.Os 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 "uint8_t *data_ptr" 87.Fa "uint32_t dxfer_len" 88.Fa "uint32_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 "uint8_t *data_ptr" 98.Fa "uint32_t dxfer_len" 99.Fa "uint32_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 "uint8_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 "uint8_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 "uint8_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, e.g., \& 174.Fn cam_fill_csio , 175.Fn scsi_start_stop , 176and 177.Fn scsi_read_write . 178.Pp 179.Fn csio_build 180builds up a 181.Va ccb_scsiio 182structure based on the information provided in 183the variable argument list. 184It gracefully handles a NULL 185.Fa data_ptr 186argument passed to it. 187.Pp 188.Fa dxfer_len 189is the length of the data phase; the data transfer direction is 190determined by the 191.Fa flags 192argument. 193.Pp 194.Fa data_ptr 195is the data buffer used during the 196.Tn SCSI 197data phase. 198If no data is to be 199transferred for the 200.Tn SCSI 201command in question, this should be set to NULL. 202If there is data to 203transfer for the command, this buffer must be at least 204.Fa dxfer_len 205long. 206.Pp 207.Fa flags 208are the flags defined in 209.In cam/cam_ccb.h : 210.Bd -literal 211/* Common CCB header */ 212/* CAM CCB flags */ 213typedef enum { 214 CAM_CDB_POINTER = 0x00000001,/* The CDB field is a pointer */ 215 CAM_QUEUE_ENABLE = 0x00000002,/* SIM queue actions are enabled */ 216 CAM_CDB_LINKED = 0x00000004,/* CCB contains a linked CDB */ 217 CAM_SCATTER_VALID = 0x00000010,/* Scatter/gather list is valid */ 218 CAM_DIS_AUTOSENSE = 0x00000020,/* Disable autosense feature */ 219 CAM_DIR_RESV = 0x00000000,/* Data direction (00:reserved) */ 220 CAM_DIR_IN = 0x00000040,/* Data direction (01:DATA IN) */ 221 CAM_DIR_OUT = 0x00000080,/* Data direction (10:DATA OUT) */ 222 CAM_DIR_NONE = 0x000000C0,/* Data direction (11:no data) */ 223 CAM_DIR_MASK = 0x000000C0,/* Data direction Mask */ 224 CAM_SOFT_RST_OP = 0x00000100,/* Use Soft reset alternative */ 225 CAM_ENG_SYNC = 0x00000200,/* Flush resid bytes on complete */ 226 CAM_DEV_QFRZDIS = 0x00000400,/* Disable DEV Q freezing */ 227 CAM_DEV_QFREEZE = 0x00000800,/* Freeze DEV Q on execution */ 228 CAM_HIGH_POWER = 0x00001000,/* Command takes a lot of power */ 229 CAM_SENSE_PTR = 0x00002000,/* Sense data is a pointer */ 230 CAM_SENSE_PHYS = 0x00004000,/* Sense pointer is physical addr*/ 231 CAM_TAG_ACTION_VALID = 0x00008000,/* Use the tag action in this ccb*/ 232 CAM_PASS_ERR_RECOVER = 0x00010000,/* Pass driver does err. recovery*/ 233 CAM_DIS_DISCONNECT = 0x00020000,/* Disable disconnect */ 234 CAM_SG_LIST_PHYS = 0x00040000,/* SG list has physical addrs. */ 235 CAM_MSG_BUF_PHYS = 0x00080000,/* Message buffer ptr is physical*/ 236 CAM_SNS_BUF_PHYS = 0x00100000,/* Autosense data ptr is physical*/ 237 CAM_DATA_PHYS = 0x00200000,/* SG/Buffer data ptrs are phys. */ 238 CAM_CDB_PHYS = 0x00400000,/* CDB pointer is physical */ 239 CAM_ENG_SGLIST = 0x00800000,/* SG list is for the HBA engine */ 240 241/* Phase cognizant mode flags */ 242 CAM_DIS_AUTOSRP = 0x01000000,/* Disable autosave/restore ptrs */ 243 CAM_DIS_AUTODISC = 0x02000000,/* Disable auto disconnect */ 244 CAM_TGT_CCB_AVAIL = 0x04000000,/* Target CCB available */ 245 CAM_TGT_PHASE_MODE = 0x08000000,/* The SIM runs in phase mode */ 246 CAM_MSGB_VALID = 0x20000000,/* Message buffer valid */ 247 CAM_STATUS_VALID = 0x40000000,/* Status buffer valid */ 248 CAM_DATAB_VALID = 0x80000000,/* Data buffer valid */ 249 250/* Host target Mode flags */ 251 CAM_TERM_IO = 0x20000000,/* Terminate I/O Message sup. */ 252 CAM_DISCONNECT = 0x40000000,/* Disconnects are mandatory */ 253 CAM_SEND_STATUS = 0x80000000,/* Send status after data phase */ 254} ccb_flags; 255.Ed 256.Pp 257Multiple flags should be ORed together. 258Any of the CCB flags may be used, 259although it is worth noting several important ones here: 260.Bl -tag -width CAM_PASS_ERR_RECOVER 261.It Dv CAM_DIR_IN 262This indicates that the operation in question is a read operation. 263i.e., 264data is being read from the 265.Tn SCSI 266device to the user-supplied buffer. 267.It Dv CAM_DIR_OUT 268This indicates that the operation is a write operation. 269i.e., data is being 270written from the user-supplied buffer to the device. 271.It Dv CAM_DIR_NONE 272This indicates that there is no data to be transferred for this command. 273.It Dv CAM_DEV_QFRZDIS 274This flag disables device queue freezing as an error recovery mechanism. 275.It Dv CAM_PASS_ERR_RECOVER 276This flag tells the 277.Xr pass 4 278driver to enable error recovery. 279The default is to not perform error 280recovery, which means that the retry count will not be honored without this 281flag, among other things. 282.It Dv CAM_DATA_PHYS 283This indicates that the address contained in 284.Fa data_ptr 285is a physical address, not a virtual address. 286.El 287.Pp 288The 289.Fa retry_count 290tells the kernel how many times to retry the command in question. 291The 292retry count is ignored unless the 293.Xr pass 4 294driver is told to enable error recovery via the 295.Dv CAM_PASS_ERR_RECOVER 296flag. 297.Pp 298The 299.Fa timeout 300tells the kernel how long to wait for the given command to complete. 301If 302the timeout expires and the command has not completed, the CCB will be 303returned from the kernel with an appropriate error status. 304.Pp 305.Fa cmd_spec 306is a CDB format specifier used to build up the SCSI CDB. 307This text string is made up of a list of field specifiers. 308Field 309specifiers specify the value for each CDB field (including indicating 310that the value be taken from the next argument in the 311variable argument list), the width 312of the field in bits or bytes, and an optional name. 313White space is 314ignored, and the pound sign ('#') introduces a comment that ends at the 315end of the current line. 316.Pp 317The optional name is the first part of a field specifier and 318is in curly braces. 319The text in curly braces in this example are 320the names: 321.Dl "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page" 322.Pp 323This field specifier has two one bit fields and one six bit field. 324The second one bit field is the constant value 0 and the first 325one bit field and the six bit field are taken from the variable 326argument list. 327Multi byte fields are swapped into the SCSI byte order in the 328CDB and white space is ignored. 329.Pp 330When the field is a hex value or the letter v, (e.g., 331.Fa "1A" 332or 333.Fa "v" ) 334then a single byte value 335is copied to the next unused byte of the CDB. 336When the letter 337.Fa v 338is used the next integer argument is taken from the variable argument list 339and that value used. 340.Pp 341A constant hex value followed by a field width specifier or the letter 342.Fa v 343followed by a field width specifier (e.g., 344.Fa 3:4 , 345.Fa 3:b4 , 346.Fa 3:i3 , 347.Fa v:i3 ) 348specifies a field of a given bit or byte width. 349Either the constant value or (for the V specifier) the next integer value from 350the variable argument list is copied to the next unused 351bits or bytes of the CDB. 352.Pp 353A decimal number or the letter 354.Fa b 355followed by a decimal number field width indicates a bit field of that width. 356The bit fields are packed as tightly as possible beginning with the 357high bit (so that it reads the same as the SCSI spec), and a new byte of 358the CDB is started whenever a byte fills completely or when an 359.Fa i 360field is encountered. 361.Pp 362A field width specifier consisting of the letter 363.Fa i 364followed by either 3651, 2, 3 or 4 indicates a 1, 2, 3 or 4 byte integral value that must 366be swapped into SCSI byte order (MSB first). 367.Pp 368For the 369.Fa v 370field specifier the next integer argument is taken from the variable argument 371list and that value is used swapped into SCSI byte order. 372.Pp 373.Fn csio_build_visit 374operates similarly to 375.Fn csio_build , 376except that the values to substitute for variable arguments in 377.Fa cmd_spec 378are retrieved via the 379.Fn arg_get 380function passed in to 381.Fn csio_build_visit 382instead of via 383.Xr stdarg 3 . 384The 385.Fn arg_get 386function takes two arguments: 387.Bl -tag -width field_name 388.It Fa gethook 389is passed into the 390.Fn arg_get 391function at each invocation. 392This enables the 393.Fn arg_get 394function to keep some state in between calls without using global or static 395variables. 396.It Fa field_name 397is the field name supplied in 398.Fa fmt , 399if any. 400.El 401.Pp 402.Fn csio_decode 403is used to decode information from the data in phase of the SCSI 404transfer. 405.Pp 406The decoding is similar to 407the command specifier processing of 408.Fn csio_build 409except that the data is extracted from the data pointed to by 410.Fa csio->data_ptr . 411The stdarg list should be pointers to integers instead of integer 412values. 413A seek field type and a suppression modifier are added. 414The 415.Fa * 416suppression modifier (e.g., 417.Fa *i3 418or 419.Fa *b4 ) 420suppresses assignment from the field and can be used to skip 421over bytes or bits in the data, without having to copy 422them to a dummy variable in the arg list. 423.Pp 424The seek field type 425.Fa s 426permits you to skip over data. 427This seeks to an absolute position 428.Pq Fa s3 429or a relative position 430.Pq Fa s+3 431in the data, based on whether or not the presence of the '+' sign. 432The seek value can be specified as 433.Fa v 434and the next integer value from the argument list will be 435used as the seek value. 436.Pp 437.Fn csio_decode_visit 438operates like 439.Fn csio_decode 440except that instead of placing the decoded contents of the buffer in 441variadic arguments, the decoded buffer contents are returned to the user 442via the 443.Fn arg_put 444function that is passed in. 445The 446.Fn arg_put 447function takes several arguments: 448.Bl -tag -width letter 449.It Fa hook 450The "hook" is a mechanism to allow the 451.Fn arg_put 452function to save state in between calls. 453.It Fa letter 454is the letter describing the format of the argument being passed into the 455function. 456.It Fa val 457is a void pointer to the value being passed into the function. 458.It Fa count 459is the size of the value being passed into the 460.Fn arg_put 461function. 462The argument format determines the unit of measure. 463.It Fa name 464This is a text description of the field, if one was provided in the 465.Fa fmt . 466.El 467.Pp 468.Fn buff_decode 469decodes an arbitrary data buffer using the method 470described above for 471.Fn csio_decode . 472.Pp 473.Fn buff_decode_visit 474decodes an arbitrary data buffer using the method described above for 475.Fn csio_decode_visit . 476.Pp 477.Fn csio_encode 478encodes the 479.Fa data_ptr 480portion (not the CDB!) of a 481.Va ccb_scsiio 482structure, using the method described above for 483.Fn csio_build . 484.Pp 485.Fn csio_encode_visit 486encodes the 487.Fa data_ptr 488portion (not the CDB!) of a 489.Va ccb_scsiio 490structure, using the method described above for 491.Fn csio_build_visit . 492.Pp 493.Fn buff_encode_visit 494encodes an arbitrary data pointer, using the method described 495above for 496.Fn csio_build_visit . 497.Sh RETURN VALUES 498.Fn csio_build , 499.Fn csio_build_visit , 500.Fn csio_encode , 501.Fn csio_encode_visit , 502and 503.Fn buff_encode_visit 504return the number of fields processed. 505.Pp 506.Fn csio_decode , 507.Fn csio_decode_visit , 508.Fn buff_decode , 509and 510.Fn buff_decode_visit 511return the number of assignments performed. 512.Sh SEE ALSO 513.Xr cam 3 , 514.Xr pass 4 , 515.Xr camcontrol 8 516.Sh HISTORY 517The CAM versions of these functions are based upon similar functions 518implemented for the old 519.Fx 520.Tn SCSI 521layer. 522The encoding/decoding functions in the old 523.Tn SCSI 524code were written by 525.An Peter Dufault Aq Mt dufault@hda.com . 526.Pp 527Many systems have comparable interfaces to permit a user to construct a 528SCSI command in user space. 529.Pp 530The old 531.Va scsireq 532data structure was almost identical to the SGI /dev/scsi data structure. 533If anyone knows the name of the authors it should go here; 534Peter Dufault 535first read about it in a 1989 Sun Expert magazine. 536.Pp 537The new CCB data structures are derived from the CAM-2 and CAM-3 538specifications. 539.Pp 540.An Peter Dufault 541implemented a clone of SGI's interface in 542.Bx 386 543that 544led to the original 545.Fx 546.Tn SCSI 547library and the related kernel ioctl. 548If anyone needs that for compatibility, contact 549.Mt dufault@hda.com . 550.Sh AUTHORS 551.An -nosplit 552.An Kenneth Merry Aq Mt ken@FreeBSD.org 553implemented the CAM versions of these encoding and decoding functions. 554This current work is based upon earlier work by 555.An Peter Dufault Aq Mt dufault@hda.com . 556.Sh BUGS 557There should probably be a function that encodes both the CDB and the data 558buffer portions of a 559.Tn SCSI 560CCB. 561I discovered this while implementing the arbitrary command execution 562code in 563.Xr camcontrol 8 , 564but I have not yet had time to implement such a function. 565.Pp 566Some of the CCB flag descriptions really do not belong here. 567Rather they 568belong in a generic CCB man page. 569Since that man page has not yet been 570written, the shorter descriptions here will have to suffice. 571