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.Dd March 11, 2017 31.Dt CAM 3 32.Os 33.Sh NAME 34.Nm cam_open_device , 35.Nm cam_open_spec_device , 36.Nm cam_open_btl , 37.Nm cam_open_pass , 38.Nm cam_close_device , 39.Nm cam_close_spec_device , 40.Nm cam_getccb , 41.Nm cam_send_ccb , 42.Nm cam_freeccb , 43.Nm cam_path_string , 44.Nm cam_device_dup , 45.Nm cam_device_copy , 46.Nm cam_get_device 47.Nd CAM user library 48.Sh LIBRARY 49.Lb libcam 50.Sh SYNOPSIS 51.In stdio.h 52.In camlib.h 53.Ft struct cam_device * 54.Fo cam_open_device 55.Fa "const char *path" 56.Fa "int flags" 57.Fc 58.Ft struct cam_device * 59.Fo cam_open_spec_device 60.Fa "const char *dev_name" 61.Fa "int unit" 62.Fa "int flags" 63.Fa "struct cam_device *device" 64.Fc 65.Ft struct cam_device * 66.Fo cam_open_btl 67.Fa "path_id_t path_id" 68.Fa "target_id_t target_id" 69.Fa "lun_id_t target_lun" 70.Fa "int flags" 71.Fa "struct cam_device *device" 72.Fc 73.Ft struct cam_device * 74.Fo cam_open_pass 75.Fa "const char *path" 76.Fa "int flags" 77.Fa "struct cam_device *device" 78.Fc 79.Ft void 80.Fo cam_close_device 81.Fa "struct cam_device *dev" 82.Fc 83.Ft void 84.Fo cam_close_spec_device 85.Fa "struct cam_device *dev" 86.Fc 87.Ft union ccb * 88.Fo cam_getccb 89.Fa "struct cam_device *dev" 90.Fc 91.Ft int 92.Fo cam_send_ccb 93.Fa "struct cam_device *device" 94.Fa "union ccb *ccb" 95.Fc 96.Ft void 97.Fo cam_freeccb 98.Fa "union ccb *ccb" 99.Fc 100.Ft char * 101.Fo cam_path_string 102.Fa "struct cam_device *dev" 103.Fa "char *str" 104.Fa "int len" 105.Fc 106.Ft struct cam_device * 107.Fo cam_device_dup 108.Fa "struct cam_device *device" 109.Fc 110.Ft void 111.Fo cam_device_copy 112.Fa "struct cam_device *src" 113.Fa "struct cam_device *dst" 114.Fc 115.Ft int 116.Fo cam_get_device 117.Fa "const char *path" 118.Fa "char *dev_name" 119.Fa "int devnamelen" 120.Fa "int *unit" 121.Fc 122.Sh DESCRIPTION 123The CAM library consists of a number of functions designed to aid in 124programming with the CAM subsystem. 125This man page covers the basic set of 126library functions. 127More functions are documented in the man pages listed 128below. 129.Pp 130Many of the CAM library functions use the 131.Va cam_device 132structure: 133.Bd -literal 134struct cam_device { 135 char device_path[MAXPATHLEN+1];/* 136 * Pathname of the 137 * device given by the 138 * user. This may be 139 * null if the user 140 * states the device 141 * name and unit number 142 * separately. 143 */ 144 char given_dev_name[DEV_IDLEN+1];/* 145 * Device name given by 146 * the user. 147 */ 148 uint32_t given_unit_number; /* 149 * Unit number given by 150 * the user. 151 */ 152 char device_name[DEV_IDLEN+1];/* 153 * Name of the device, 154 * e.g., 'pass' 155 */ 156 uint32_t dev_unit_num; /* Unit number of the passthrough 157 * device associated with this 158 * particular device. 159 */ 160 161 char sim_name[SIM_IDLEN+1];/* 162 * Controller name, e.g., 'ahc' 163 */ 164 uint32_t sim_unit_number; /* Controller unit number */ 165 uint32_t bus_id; /* Controller bus number */ 166 lun_id_t target_lun; /* Logical Unit Number */ 167 target_id_t target_id; /* Target ID */ 168 path_id_t path_id; /* System SCSI bus number */ 169 uint16_t pd_type; /* type of peripheral device */ 170 struct scsi_inquiry_data inq_data; /* SCSI Inquiry data */ 171 uint8_t serial_num[252]; /* device serial number */ 172 uint8_t serial_num_len; /* length of the serial number */ 173 uint8_t sync_period; /* Negotiated sync period */ 174 uint8_t sync_offset; /* Negotiated sync offset */ 175 uint8_t bus_width; /* Negotiated bus width */ 176 int fd; /* file descriptor for device */ 177}; 178.Ed 179.Pp 180.Fn cam_open_device 181takes as arguments a string describing the device it is to open, and 182.Ar flags 183suitable for passing to 184.Xr open 2 . 185The "path" passed in may actually be most any type of string that contains 186a device name and unit number to be opened. 187The string will be parsed by 188.Fn cam_get_device 189into a device name and unit number. 190Once the device name and unit number 191are determined, a lookup is performed to determine the passthrough device 192that corresponds to the given device. 193.Pp 194.Fn cam_open_spec_device 195opens the 196.Xr pass 4 197device that corresponds to the device name and unit number passed in. 198The 199.Ar flags 200should be flags suitable for passing to 201.Xr open 2 . 202The 203.Ar device 204argument is optional. 205The user may supply pre-allocated space for the 206.Va cam_device 207structure. 208If the 209.Ar device 210argument is 211.Dv NULL , 212.Fn cam_open_spec_device 213will allocate space for the 214.Va cam_device 215structure using 216.Xr malloc 3 . 217.Pp 218.Fn cam_open_btl 219is similar to 220.Fn cam_open_spec_device , 221except that it takes a 222.Tn SCSI 223bus, target and logical unit instead of a device name and unit number as 224arguments. 225The 226.Va path_id 227argument is the CAM equivalent of a 228.Tn SCSI 229bus number. 230It represents the logical bus number in the system. 231The 232.Ar flags 233should be flags suitable for passing to 234.Xr open 2 . 235As with 236.Fn cam_open_spec_device , 237the 238.Fa device 239argument is optional. 240.Pp 241.Fn cam_open_pass 242takes as an argument the 243.Fa path 244of a 245.Xr pass 4 246device to open. 247No translation or lookup is performed, so the path passed 248in must be that of a CAM 249.Xr pass 4 250device. 251The 252.Fa flags 253should be flags suitable for passing to 254.Xr open 2 . 255The 256.Fa device 257argument, as with 258.Fn cam_open_spec_device 259and 260.Fn cam_open_btl , 261should be 262.Dv NULL 263if the user wants the CAM library to allocate space for the 264.Va cam_device 265structure. 266.Fn cam_close_device 267frees the 268.Va cam_device 269structure allocated by one of the above open() calls, and closes the file 270descriptor to the passthrough device. 271This routine should not be called if 272the user allocated space for the 273.Va cam_device 274structure. 275Instead, the user should call 276.Fn cam_close_spec_device . 277.Pp 278.Fn cam_close_spec_device 279merely closes the file descriptor opened in one of the open() routines 280described above. 281This function should be called when the 282.Va cam_device 283structure was allocated by the caller, rather than the CAM library. 284.Pp 285.Fn cam_getccb 286allocates a CCB 287using 288.Xr malloc 3 289and sets fields in the CCB header using values from the 290.Va cam_device 291structure. 292.Pp 293.Fn cam_send_ccb 294sends the given 295.Va ccb 296to the 297.Fa device 298described in the 299.Va cam_device 300structure. 301.Pp 302.Fn cam_freeccb 303frees CCBs allocated by 304.Fn cam_getccb . 305If 306.Va ccb 307is 308.Dv NULL , 309no action is taken. 310.Pp 311.Fn cam_path_string 312takes as arguments a 313.Va cam_device 314structure, and a string with length 315.Fa len . 316It creates a colon-terminated printing prefix string similar to the ones 317used by the kernel. 318e.g.: "(cd0:ahc1:0:4:0): ". 319.Fn cam_path_string 320will place at most 321.Fa len Ns \-1 322characters into 323.Ar str . 324The 325.Ar len Ns 'th 326character will be the terminating 327.Ql \e0 . 328.Pp 329.Fn cam_device_dup 330operates in a fashion similar to 331.Xr strdup 3 . 332It allocates space for a 333.Va cam_device 334structure and copies the contents of the passed-in 335.Fa device 336structure to the newly allocated structure. 337.Pp 338.Fn cam_device_copy 339copies the 340.Fa src 341structure to 342.Fa dst . 343.Pp 344.Fn cam_get_device 345takes a 346.Fa path 347argument containing a string with a device name followed by a unit number. 348It then breaks the string down into a device name and unit number, and 349passes them back in 350.Fa dev_name 351and 352.Fa unit , 353respectively. 354.Fn cam_get_device 355can handle strings of the following forms, at least: 356.Pp 357.Bl -tag -width 1234 -compact 358.It /dev/foo1 359.It foo0 360.It nsa2 361.El 362.Pp 363.Fn cam_get_device 364is provided as a convenience function for applications that need to provide 365functionality similar to 366.Fn cam_open_device . 367.Sh RETURN VALUES 368.Fn cam_open_device , 369.Fn cam_open_spec_device , 370.Fn cam_open_btl , 371and 372.Fn cam_open_pass 373return a pointer to a 374.Va cam_device 375structure, or 376.Dv NULL 377if there was an error. 378.Pp 379.Fn cam_getccb 380returns an allocated and partially initialized CCB, or 381.Dv NULL 382if allocation of the CCB failed. 383.Pp 384.Fn cam_send_ccb 385returns a value of -1 if an error occurred, and 386.Va errno 387is set to indicate the error. 388.Pp 389.Fn cam_path_string 390returns a filled printing prefix string as a convenience. 391This is the same 392.Fa str 393that is passed into 394.Fn cam_path_string . 395.Pp 396.Fn cam_device_dup 397returns a copy of the 398.Va device 399passed in, or 400.Dv NULL 401if an error occurred. 402.Pp 403.Fn cam_get_device 404returns 0 for success, and -1 to indicate failure. 405.Pp 406If an error is returned from one of the base CAM library functions 407described here, the reason for the error is generally printed in the global 408string 409.Va cam_errbuf 410which is 411.Dv CAM_ERRBUF_SIZE 412characters long. 413.Sh SEE ALSO 414.Xr cam_cdbparse 3 , 415.Xr pass 4 , 416.Xr camcontrol 8 417.Sh HISTORY 418The CAM library first appeared in 419.Fx 3.0 . 420.Sh AUTHORS 421.An Kenneth Merry Aq Mt ken@FreeBSD.org 422.Sh BUGS 423.Fn cam_open_device 424does not check to see if the 425.Fa path 426passed in is a symlink to something. 427It also does not check to see if the 428.Fa path 429passed in is an actual 430.Xr pass 4 431device. 432The former would be rather easy to implement, but the latter would 433require a definitive way to identify a device node as a 434.Xr pass 4 435device. 436.Pp 437Some of the functions are possibly misnamed or poorly named. 438