.\" .\" Copyright (c) 1998 Kenneth D. Merry. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. The name of the author may not be used to endorse or promote products .\" derived from this software without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $FreeBSD$ .\" .\" This man page borrows heavily from the old scsi(3) man page, which had .\" the following copyright: .\" .\" Copyright (c) 1994 HD Associates (hd@world.std.com) .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by HD Associates .\" 4. Neither the name of the HD Associates nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" .Dd October 13, 1998 .Os FreeBSD 3.0 .Dt CAM_CDBPARSE 3 .Sh NAME .Nm csio_build , .Nm csio_build_visit , .Nm csio_decode , .Nm csio_decode_visit , .Nm buff_decode , .Nm buff_decode_visit , .Nm csio_encode , .Nm csio_encode_visit , .Nm buff_encode_visit .Nd CAM user library SCSI buffer parsing routines .Sh LIBRARY .Lb libcam .Sh SYNOPSIS .Fd #include .Fd #include .Ft int .Fo csio_build .Fa "struct ccb_scsiio *csio" .Fa "u_int8_t *data_ptr" .Fa "u_int32_t dxfer_len" .Fa "u_int32_t flags" .Fa "int retry_count" .Fa "int timeout" .Fa "char *cmd_spec" .Fa "..." .Fc .Ft int .Fo csio_build_visit .Fa "struct ccb_scsiio *csio" .Fa "u_int8_t *data_ptr" .Fa "u_int32_t dxfer_len" .Fa "u_int32_t flags" .Fa "int retry_count" .Fa "int timeout" .Fa "char *cmd_spec" .Fa "int (*arg_get)(void *hook, char *field_name)" .Fa "void *gethook" .Fc .Ft int .Fo csio_decode .Fa "struct ccb_scsiio *csio" .Fa "char *fmt" .Fa "..." .Fc .Ft int .Fo csio_decode_visit .Fa "struct ccb_scsiio *csio" .Fa "char *fmt" .Fa "void (*arg_put)(void *hook" .Fa "int letter" .Fa "void *val" .Fa "int count" .Fa "char *name)" .Fa "void *puthook" .Fc .Ft int .Fo buff_decode .Fa "u_int8_t *buff" .Fa "size_t len" .Fa "char *fmt" .Fa "..." .Fc .Ft int .Fo buff_decode_visit .Fa "u_int8_t *buff" .Fa "size_t len" .Fa "char *fmt" .Fa "void (*arg_put)(void *, int, void *, int, char *)" .Fa "void *puthook" .Fc .Ft int .Fo csio_encode .Fa "struct ccb_scsiio *csio" .Fa "char *fmt" .Fa "..." .Fc .Ft int .Fo csio_encode_visit .Fa "struct ccb_scsiio *csio" .Fa "char *fmt" .Fa "int (*arg_get)(void *hook, char *field_name)" .Fa "void *gethook" .Fc .Ft int .Fo buff_encode_visit .Fa "u_int8_t *buff" .Fa "size_t len" .Fa "char *fmt" .Fa "int (*arg_get)(void *hook, char *field_name)" .Fa "void *gethook" .Fc .Sh DESCRIPTION The CAM buffer/CDB encoding and decoding routines provide a relatively easy migration path for userland .Tn SCSI applications written with the similarly-named .Va scsireq_ Ns * functions from the old FreeBSD .Tn SCSI layer. .Pp These functions may be used in new applications, but users may find it easier to use the various SCSI CCB building functions included with the .Xr cam 3 library. (e.g. .Fn cam_fill_csio , .Fn scsi_start_stop , and .Fn scsi_read_write ) .Pp .Fn csio_build builds up a .Va ccb_scsiio structure based on the information provided in the variable argument list. It gracefully handles a NULL .Fa data_ptr argument passed to it. .Pp .Fa dxfer_len is the length of the data phase; the data transfer direction is determined by the .Fa flags argument. .Pp .Fa data_ptr is the data buffer used during the .Tn SCSI data phase. If no data is to be transferred for the .Tn SCSI command in question, this should be set to NULL. If there is data to transfer for the command, this buffer must be at least .Fa dxfer_len long. .Pp .Fa flags are the flags defined in .Aq Pa cam/cam_ccb.h : .Bd -literal /* Common CCB header */ /* CAM CCB flags */ typedef enum { CAM_CDB_POINTER = 0x00000001,/* The CDB field is a pointer */ CAM_QUEUE_ENABLE = 0x00000002,/* SIM queue actions are enabled */ CAM_CDB_LINKED = 0x00000004,/* CCB contains a linked CDB */ CAM_SCATTER_VALID = 0x00000010,/* Scatter/gather list is valid */ CAM_DIS_AUTOSENSE = 0x00000020,/* Disable autosense feature */ CAM_DIR_RESV = 0x00000000,/* Data direction (00:reserved) */ CAM_DIR_IN = 0x00000040,/* Data direction (01:DATA IN) */ CAM_DIR_OUT = 0x00000080,/* Data direction (10:DATA OUT) */ CAM_DIR_NONE = 0x000000C0,/* Data direction (11:no data) */ CAM_DIR_MASK = 0x000000C0,/* Data direction Mask */ CAM_SOFT_RST_OP = 0x00000100,/* Use Soft reset alternative */ CAM_ENG_SYNC = 0x00000200,/* Flush resid bytes on complete */ CAM_DEV_QFRZDIS = 0x00000400,/* Disable DEV Q freezing */ CAM_DEV_QFREEZE = 0x00000800,/* Freeze DEV Q on execution */ CAM_HIGH_POWER = 0x00001000,/* Command takes a lot of power */ CAM_SENSE_PTR = 0x00002000,/* Sense data is a pointer */ CAM_SENSE_PHYS = 0x00004000,/* Sense pointer is physical addr*/ CAM_TAG_ACTION_VALID = 0x00008000,/* Use the tag action in this ccb*/ CAM_PASS_ERR_RECOVER = 0x00010000,/* Pass driver does err. recovery*/ CAM_DIS_DISCONNECT = 0x00020000,/* Disable disconnect */ CAM_SG_LIST_PHYS = 0x00040000,/* SG list has physical addrs. */ CAM_MSG_BUF_PHYS = 0x00080000,/* Message buffer ptr is physical*/ CAM_SNS_BUF_PHYS = 0x00100000,/* Autosense data ptr is physical*/ CAM_DATA_PHYS = 0x00200000,/* SG/Buffer data ptrs are phys. */ CAM_CDB_PHYS = 0x00400000,/* CDB poiner is physical */ CAM_ENG_SGLIST = 0x00800000,/* SG list is for the HBA engine */ /* Phase cognizant mode flags */ CAM_DIS_AUTOSRP = 0x01000000,/* Diable autosave/restore ptrs */ CAM_DIS_AUTODISC = 0x02000000,/* Disable auto disconnect */ CAM_TGT_CCB_AVAIL = 0x04000000,/* Target CCB available */ CAM_TGT_PHASE_MODE = 0x08000000,/* The SIM runs in phase mode */ CAM_MSGB_VALID = 0x20000000,/* Message buffer valid */ CAM_STATUS_VALID = 0x40000000,/* Status buffer valid */ CAM_DATAB_VALID = 0x80000000,/* Data buffer valid */ /* Host target Mode flags */ CAM_TERM_IO = 0x20000000,/* Terminate I/O Message sup. */ CAM_DISCONNECT = 0x40000000,/* Disconnects are mandatory */ CAM_SEND_STATUS = 0x80000000,/* Send status after data phase */ } ccb_flags; .Ed .Pp Multiple flags should be ORed together. Any of the CCB flags may be used, although it is worth noting several important ones here: .Pp .Bl -tag -width CAM_PASS_ERR_RECOVER .It Dv CAM_DIR_IN This indicates that the operation in question is a read operation. i.e., data is being read from the .Tn SCSI device to the user-supplied buffer. .It Dv CAM_DIR_OUT This indicates that the operation is a write operation. i.e. data is being written from the user-supplied buffer to the device. .It Dv CAM_DIR_NONE This indicates that there is no data to be transferred for this command. .It Dv CAM_DEV_QFRZDIS This flag disables device queue freezing as an error recovery mechanism. .It Dv CAM_PASS_ERR_RECOVER This flag tells the .Xr pass 4 driver to enable error recovery. The default is to not perform error recovery, which means that the retry count won't be honored without this flag, among other things. .It Dv CAM_DATA_PHYS This indicates that the address contained in .Fa data_ptr is a physical address, not a virtual address. .El .Pp The .Fa retry_count tells the kernel how many times to retry the command in question. The retry count is ignored unless the .Xr pass 4 driver is told to enable error recovery via the .Dv CAM_PASS_ERR_RECOVER flag. .Pp The .Fa timeout tells the kernel how long to wait for the given command to complete. If the timeout expires and the command hasn't completed, the CCB will be returned from the kernel with an appropriate error status. .Pp .Fa cmd_spec is a CDB format specifier used to build up the SCSI CDB. This text string is made up of a list of field specifiers. Field specifiers specify the value for each CDB field (including indicating that the value be taken from the next argument in the variable argument list), the width of the field in bits or bytes, and an optional name. White space is ignored, and the pound sign ('#') introduces a comment that ends at the end of the current line. .Pp The optional name is the first part of a field specifier and is in curly braces. The text in curly braces in this example are the names: .Bd -literal -offset indent .Fa "{PS} v:b1 {Reserved} 0:b1 {Page Code} v:b6 # Mode select page" .Ed .Pp This field specifier has two one bit fields and one six bit field. The second one bit field is the constant value 0 and the first one bit field and the six bit field are taken from the variable argument list. Multi byte fields are swapped into the SCSI byte order in the CDB and white space is ignored. .Pp When the field is a hex value or the letter v, (e.g., .Fa "1A" or .Fa "v" ) then a single byte value is copied to the next unused byte of the CDB. When the letter .Fa v is used the next integer argument is taken from the variable argument list and that value used. .Pp A constant hex value followed by a field width specifier or the letter .Fa v followed by a field width specifier (e.g., .Fa 3:4 , .Fa 3:b4 , .Fa 3:i3 , .FR v:i3 ) specifies a field of a given bit or byte width. Either the constant value or (for the V specifier) the next integer value from the variable argument list is copied to the next unused bits or bytes of the CDB. .Pp A decimal number or the letter .Fa b followed by a decimal number field width indicates a bit field of that width. The bit fields are packed as tightly as possible beginning with the high bit (so that it reads the same as the SCSI spec), and a new byte of the CDB is started whenever a byte fills completely or when an .Fa i field is encountered. .Pp A field width specifier consisting of the letter .Fa i followed by either 1, 2, 3 or 4 indicates a 1, 2, 3 or 4 byte integral value that must be swapped into SCSI byte order (MSB first). .Pp For the .Fa v field specifier the next integer argument is taken from the variable argument list and that value is used swapped into SCSI byte order. .Pp .Fn csio_build_visit operates similarly to .Fn csio_build , except that the values to substitute for variable arguments in .Fa cmd_spec are retrieved via the .Fn arg_get function passed in to .Fn csio_build_visit instead of via .Xr stdarg 3 . The .Fn arg_get function takes two arguments: .Bl -tag -width field_name .It Fa gethook is passed into the .Fn arg_get function at each invocation. This enables the .Fn arg_get function to keep some state in between calls without using global or static variables. .It Fa field_name is the field name supplied in .Fa fmt , if any. .El .Pp .Fn csio_decode is used to decode information from the data in phase of the SCSI transfer. .Pp The decoding is similar to the command specifier processing of .Fn csio_build except that the data is extracted from the data pointed to by .Fa csio->data_ptr . The stdarg list should be pointers to integers instead of integer values. A seek field type and a suppression modifier are added. The .Fa * suppression modifier (e.g., .Fa *i3 or .Fa *b4 ) suppresses assignment from the field and can be used to skip over bytes or bits in the data, without having to copy them to a dummy variable in the arg list. .Pp The seek field type .Fa s permits you to skip over data. This seeks to an absolute position ( .Fa s3 ) or a relative position ( .Fa s+3 ) in the data, based on whether or not the presence of the '+' sign. The seek value can be specified as .Fa v and the next integer value from the argument list will be used as the seek value. .Pp .Fn csio_decode_visit operates like .Fn csio_decode except that instead of placing the decoded contents of the buffer in varardic arguments, the decoded buffer contents are returned to the user via the .Fn arg_put function that is passed in. The .Fn arg_put function takes several arguments: .Bl -tag -width letter .It Fa hook The "hook" is a mechanism to allow the .Fn arg_put function to save state in between calls. .It Fa letter is the letter describing the format of the argument being passed into the function. .It Fa val is a void pointer to the value being passed into the function. .It Fa count is the number of arguments being passed into the .Fn arg_put function. At present this will only be set to 1. .It Fa name This is a text description of the field, if one was provided in the .Fa fmt . .El .Pp .Fn buff_decode decodes an arbitrary data buffer using the method described above for .Fn csio_decode . .Pp .Fn buff_decode_visit decodes an arbitrary data buffer using the method described above for .Fn csio_decode_visit . .Pp .Fn csio_encode encodes the .Fa data_ptr portion (not the CDB!) of a .Va ccb_scsiio structure, using the method described above for .Fn csio_build . .Pp .Fn csio_encode_visit encodes the .Fa data_ptr portion (not the CDB!) of a .Va ccb_scsiio structure, using the method described above for .Fn csio_build_visit . .Pp .Fn buff_encode_visit encodes an arbitrary data pointer, using the method described above for .Fn csio_build_visit . .Sh RETURN VALUES .Fn csio_build , .Fn csio_build_visit , .Fn csio_encode , .Fn csio_encode_visit , and .Fn buff_encode_visit return the number of fields processed. .Pp .Fn csio_decode , .Fn csio_decode_visit , .Fn buff_decode , and .Fn buff_decode_visit return the number of assignments performed. .Sh SEE ALSO .Xr cam 3 , .Xr pass 4 , .Xr camcontrol 8 .Sh HISTORY .Pp The CAM versions of these functions are based upon similar functions implemented for the old FreeBSD .Tn SCSI layer. The encoding/decoding functions in the old .Tn SCSI code were written by Peter Dufault. .Pp Many systems have comparable interfaces to permit a user to construct a SCSI command in user space. .Pp The old .Va scsireq data structure was almost identical to the SGI /dev/scsi data structure. If anyone knows the name of the authors it should go here; Peter Dufault first read about it in a 1989 Sun Expert magazine. .Pp The new CCB data structures are derived from the CAM-2 and CAM-3 specifications. .Pp Peter Dufault implemented a clone of SGI's interface in 386bsd that led to the original FreeBSD .Tn SCSI library and the related kernel ioctl. If anyone needs that for compatibility contact dufault@hda.com. .Sh AUTHORS Kenneth Merry implemented the CAM versions of these encoding and decoding functions. This current work is based upon earlier work by Peter Dufault. .Sh BUGS There should probably be a function that encodes both the CDB and the data buffer portions of a .Tn SCSI CCB. I discovered this while implementing the arbitrary command execution code in .Xr camcontrol 8 , but I haven't yet had time to implement such a function. .Pp Some of the CCB flag descriptions really don't belong here. Rather they belong in a generic CCB man page. Since that man page hasn't yet been written, the shorter descriptions here will have to suffice.