1 /* 2 * Changes: 3 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000 4 * - get rid of some verify_areas and use __copy*user and __get/put_user 5 * for the ones that remain 6 */ 7 #include <linux/module.h> 8 #include <linux/blkdev.h> 9 #include <linux/interrupt.h> 10 #include <linux/errno.h> 11 #include <linux/kernel.h> 12 #include <linux/sched.h> 13 #include <linux/mm.h> 14 #include <linux/string.h> 15 #include <asm/uaccess.h> 16 17 #include <scsi/scsi.h> 18 #include <scsi/scsi_device.h> 19 #include <scsi/scsi_eh.h> 20 #include <scsi/scsi_host.h> 21 #include <scsi/scsi_ioctl.h> 22 #include <scsi/scsi_request.h> 23 #include <scsi/sg.h> 24 #include <scsi/scsi_dbg.h> 25 26 #include "scsi_logging.h" 27 28 #define NORMAL_RETRIES 5 29 #define IOCTL_NORMAL_TIMEOUT (10 * HZ) 30 31 #define MAX_BUF PAGE_SIZE 32 33 /** 34 * ioctl_probe -- return host identification 35 * @host: host to identify 36 * @buffer: userspace buffer for identification 37 * 38 * Return an identifying string at @buffer, if @buffer is non-NULL, filling 39 * to the length stored at * (int *) @buffer. 40 */ 41 static int ioctl_probe(struct Scsi_Host *host, void __user *buffer) 42 { 43 unsigned int len, slen; 44 const char *string; 45 46 if (buffer) { 47 if (get_user(len, (unsigned int __user *) buffer)) 48 return -EFAULT; 49 50 if (host->hostt->info) 51 string = host->hostt->info(host); 52 else 53 string = host->hostt->name; 54 if (string) { 55 slen = strlen(string); 56 if (len > slen) 57 len = slen + 1; 58 if (copy_to_user(buffer, string, len)) 59 return -EFAULT; 60 } 61 } 62 return 1; 63 } 64 65 /* 66 67 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host. 68 * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES variables are used. 69 * 70 * dev is the SCSI device struct ptr, *(int *) arg is the length of the 71 * input data, if any, not including the command string & counts, 72 * *((int *)arg + 1) is the output buffer size in bytes. 73 * 74 * *(char *) ((int *) arg)[2] the actual command byte. 75 * 76 * Note that if more than MAX_BUF bytes are requested to be transferred, 77 * the ioctl will fail with error EINVAL. 78 * 79 * This size *does not* include the initial lengths that were passed. 80 * 81 * The SCSI command is read from the memory location immediately after the 82 * length words, and the input data is right after the command. The SCSI 83 * routines know the command size based on the opcode decode. 84 * 85 * The output area is then filled in starting from the command byte. 86 */ 87 88 static int ioctl_internal_command(struct scsi_device *sdev, char *cmd, 89 int timeout, int retries) 90 { 91 int result; 92 struct scsi_sense_hdr sshdr; 93 94 SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", *cmd)); 95 96 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, 97 &sshdr, timeout, retries); 98 99 SCSI_LOG_IOCTL(2, printk("Ioctl returned 0x%x\n", result)); 100 101 if ((driver_byte(result) & DRIVER_SENSE) && 102 (scsi_sense_valid(&sshdr))) { 103 switch (sshdr.sense_key) { 104 case ILLEGAL_REQUEST: 105 if (cmd[0] == ALLOW_MEDIUM_REMOVAL) 106 sdev->lockable = 0; 107 else 108 printk(KERN_INFO "ioctl_internal_command: " 109 "ILLEGAL REQUEST asc=0x%x ascq=0x%x\n", 110 sshdr.asc, sshdr.ascq); 111 break; 112 case NOT_READY: /* This happens if there is no disc in drive */ 113 if (sdev->removable && (cmd[0] != TEST_UNIT_READY)) { 114 printk(KERN_INFO "Device not ready. Make sure" 115 " there is a disc in the drive.\n"); 116 break; 117 } 118 case UNIT_ATTENTION: 119 if (sdev->removable) { 120 sdev->changed = 1; 121 result = 0; /* This is no longer considered an error */ 122 break; 123 } 124 default: /* Fall through for non-removable media */ 125 sdev_printk(KERN_INFO, sdev, 126 "ioctl_internal_command return code = %x\n", 127 result); 128 scsi_print_sense_hdr(" ", &sshdr); 129 break; 130 } 131 } 132 133 SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n")); 134 return result; 135 } 136 137 int scsi_set_medium_removal(struct scsi_device *sdev, char state) 138 { 139 char scsi_cmd[MAX_COMMAND_SIZE]; 140 int ret; 141 142 if (!sdev->removable || !sdev->lockable) 143 return 0; 144 145 scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL; 146 scsi_cmd[1] = 0; 147 scsi_cmd[2] = 0; 148 scsi_cmd[3] = 0; 149 scsi_cmd[4] = state; 150 scsi_cmd[5] = 0; 151 152 ret = ioctl_internal_command(sdev, scsi_cmd, 153 IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES); 154 if (ret == 0) 155 sdev->locked = (state == SCSI_REMOVAL_PREVENT); 156 return ret; 157 } 158 EXPORT_SYMBOL(scsi_set_medium_removal); 159 160 /* 161 * This interface is deprecated - users should use the scsi generic (sg) 162 * interface instead, as this is a more flexible approach to performing 163 * generic SCSI commands on a device. 164 * 165 * The structure that we are passed should look like: 166 * 167 * struct sdata { 168 * unsigned int inlen; [i] Length of data to be written to device 169 * unsigned int outlen; [i] Length of data to be read from device 170 * unsigned char cmd[x]; [i] SCSI command (6 <= x <= 12). 171 * [o] Data read from device starts here. 172 * [o] On error, sense buffer starts here. 173 * unsigned char wdata[y]; [i] Data written to device starts here. 174 * }; 175 * Notes: 176 * - The SCSI command length is determined by examining the 1st byte 177 * of the given command. There is no way to override this. 178 * - Data transfers are limited to PAGE_SIZE (4K on i386, 8K on alpha). 179 * - The length (x + y) must be at least OMAX_SB_LEN bytes long to 180 * accommodate the sense buffer when an error occurs. 181 * The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that 182 * old code will not be surprised. 183 * - If a Unix error occurs (e.g. ENOMEM) then the user will receive 184 * a negative return and the Unix error code in 'errno'. 185 * If the SCSI command succeeds then 0 is returned. 186 * Positive numbers returned are the compacted SCSI error codes (4 187 * bytes in one int) where the lowest byte is the SCSI status. 188 * See the drivers/scsi/scsi.h file for more information on this. 189 * 190 */ 191 #define OMAX_SB_LEN 16 /* Old sense buffer length */ 192 193 int scsi_ioctl_send_command(struct scsi_device *sdev, 194 struct scsi_ioctl_command __user *sic) 195 { 196 char *buf; 197 unsigned char cmd[MAX_COMMAND_SIZE]; 198 unsigned char sense[SCSI_SENSE_BUFFERSIZE]; 199 char __user *cmd_in; 200 unsigned char opcode; 201 unsigned int inlen, outlen, cmdlen; 202 unsigned int needed, buf_needed; 203 int timeout, retries, result; 204 int data_direction; 205 gfp_t gfp_mask = GFP_KERNEL; 206 207 if (!sic) 208 return -EINVAL; 209 210 if (sdev->host->unchecked_isa_dma) 211 gfp_mask |= GFP_DMA; 212 213 /* 214 * Verify that we can read at least this much. 215 */ 216 if (!access_ok(VERIFY_READ, sic, sizeof(Scsi_Ioctl_Command))) 217 return -EFAULT; 218 219 if(__get_user(inlen, &sic->inlen)) 220 return -EFAULT; 221 222 if(__get_user(outlen, &sic->outlen)) 223 return -EFAULT; 224 225 /* 226 * We do not transfer more than MAX_BUF with this interface. 227 * If the user needs to transfer more data than this, they 228 * should use scsi_generics (sg) instead. 229 */ 230 if (inlen > MAX_BUF) 231 return -EINVAL; 232 if (outlen > MAX_BUF) 233 return -EINVAL; 234 235 cmd_in = sic->data; 236 if(get_user(opcode, cmd_in)) 237 return -EFAULT; 238 239 needed = buf_needed = (inlen > outlen ? inlen : outlen); 240 if (buf_needed) { 241 buf_needed = (buf_needed + 511) & ~511; 242 if (buf_needed > MAX_BUF) 243 buf_needed = MAX_BUF; 244 buf = kzalloc(buf_needed, gfp_mask); 245 if (!buf) 246 return -ENOMEM; 247 if (inlen == 0) { 248 data_direction = DMA_FROM_DEVICE; 249 } else if (outlen == 0 ) { 250 data_direction = DMA_TO_DEVICE; 251 } else { 252 /* 253 * Can this ever happen? 254 */ 255 data_direction = DMA_BIDIRECTIONAL; 256 } 257 258 } else { 259 buf = NULL; 260 data_direction = DMA_NONE; 261 } 262 263 /* 264 * Obtain the command from the user's address space. 265 */ 266 cmdlen = COMMAND_SIZE(opcode); 267 268 result = -EFAULT; 269 270 if (!access_ok(VERIFY_READ, cmd_in, cmdlen + inlen)) 271 goto error; 272 273 if(__copy_from_user(cmd, cmd_in, cmdlen)) 274 goto error; 275 276 /* 277 * Obtain the data to be sent to the device (if any). 278 */ 279 280 if(inlen && copy_from_user(buf, cmd_in + cmdlen, inlen)) 281 goto error; 282 283 switch (opcode) { 284 case SEND_DIAGNOSTIC: 285 case FORMAT_UNIT: 286 timeout = FORMAT_UNIT_TIMEOUT; 287 retries = 1; 288 break; 289 case START_STOP: 290 timeout = START_STOP_TIMEOUT; 291 retries = NORMAL_RETRIES; 292 break; 293 case MOVE_MEDIUM: 294 timeout = MOVE_MEDIUM_TIMEOUT; 295 retries = NORMAL_RETRIES; 296 break; 297 case READ_ELEMENT_STATUS: 298 timeout = READ_ELEMENT_STATUS_TIMEOUT; 299 retries = NORMAL_RETRIES; 300 break; 301 case READ_DEFECT_DATA: 302 timeout = READ_DEFECT_DATA_TIMEOUT; 303 retries = 1; 304 break; 305 default: 306 timeout = IOCTL_NORMAL_TIMEOUT; 307 retries = NORMAL_RETRIES; 308 break; 309 } 310 311 result = scsi_execute(sdev, cmd, data_direction, buf, needed, 312 sense, timeout, retries, 0); 313 314 /* 315 * If there was an error condition, pass the info back to the user. 316 */ 317 if (result) { 318 int sb_len = sizeof(*sense); 319 320 sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len; 321 if (copy_to_user(cmd_in, sense, sb_len)) 322 result = -EFAULT; 323 } else { 324 if (outlen && copy_to_user(cmd_in, buf, outlen)) 325 result = -EFAULT; 326 } 327 328 error: 329 kfree(buf); 330 return result; 331 } 332 EXPORT_SYMBOL(scsi_ioctl_send_command); 333 334 /* 335 * The scsi_ioctl_get_pci() function places into arg the value 336 * pci_dev::slot_name (8 characters) for the PCI device (if any). 337 * Returns: 0 on success 338 * -ENXIO if there isn't a PCI device pointer 339 * (could be because the SCSI driver hasn't been 340 * updated yet, or because it isn't a SCSI 341 * device) 342 * any copy_to_user() error on failure there 343 */ 344 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg) 345 { 346 struct device *dev = scsi_get_device(sdev->host); 347 348 if (!dev) 349 return -ENXIO; 350 return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0; 351 } 352 353 354 /* 355 * the scsi_ioctl() function differs from most ioctls in that it does 356 * not take a major/minor number as the dev field. Rather, it takes 357 * a pointer to a scsi_devices[] element, a structure. 358 */ 359 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) 360 { 361 char scsi_cmd[MAX_COMMAND_SIZE]; 362 363 /* No idea how this happens.... */ 364 if (!sdev) 365 return -ENXIO; 366 367 /* 368 * If we are in the middle of error recovery, don't let anyone 369 * else try and use this device. Also, if error recovery fails, it 370 * may try and take the device offline, in which case all further 371 * access to the device is prohibited. 372 */ 373 if (!scsi_block_when_processing_errors(sdev)) 374 return -ENODEV; 375 376 /* Check for deprecated ioctls ... all the ioctls which don't 377 * follow the new unique numbering scheme are deprecated */ 378 switch (cmd) { 379 case SCSI_IOCTL_SEND_COMMAND: 380 case SCSI_IOCTL_TEST_UNIT_READY: 381 case SCSI_IOCTL_BENCHMARK_COMMAND: 382 case SCSI_IOCTL_SYNC: 383 case SCSI_IOCTL_START_UNIT: 384 case SCSI_IOCTL_STOP_UNIT: 385 printk(KERN_WARNING "program %s is using a deprecated SCSI " 386 "ioctl, please convert it to SG_IO\n", current->comm); 387 break; 388 default: 389 break; 390 } 391 392 switch (cmd) { 393 case SCSI_IOCTL_GET_IDLUN: 394 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun))) 395 return -EFAULT; 396 397 __put_user((sdev->id & 0xff) 398 + ((sdev->lun & 0xff) << 8) 399 + ((sdev->channel & 0xff) << 16) 400 + ((sdev->host->host_no & 0xff) << 24), 401 &((struct scsi_idlun __user *)arg)->dev_id); 402 __put_user(sdev->host->unique_id, 403 &((struct scsi_idlun __user *)arg)->host_unique_id); 404 return 0; 405 case SCSI_IOCTL_GET_BUS_NUMBER: 406 return put_user(sdev->host->host_no, (int __user *)arg); 407 case SCSI_IOCTL_PROBE_HOST: 408 return ioctl_probe(sdev->host, arg); 409 case SCSI_IOCTL_SEND_COMMAND: 410 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) 411 return -EACCES; 412 return scsi_ioctl_send_command(sdev, arg); 413 case SCSI_IOCTL_DOORLOCK: 414 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 415 case SCSI_IOCTL_DOORUNLOCK: 416 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 417 case SCSI_IOCTL_TEST_UNIT_READY: 418 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT, 419 NORMAL_RETRIES); 420 case SCSI_IOCTL_START_UNIT: 421 scsi_cmd[0] = START_STOP; 422 scsi_cmd[1] = 0; 423 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 424 scsi_cmd[4] = 1; 425 return ioctl_internal_command(sdev, scsi_cmd, 426 START_STOP_TIMEOUT, NORMAL_RETRIES); 427 case SCSI_IOCTL_STOP_UNIT: 428 scsi_cmd[0] = START_STOP; 429 scsi_cmd[1] = 0; 430 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 431 scsi_cmd[4] = 0; 432 return ioctl_internal_command(sdev, scsi_cmd, 433 START_STOP_TIMEOUT, NORMAL_RETRIES); 434 case SCSI_IOCTL_GET_PCI: 435 return scsi_ioctl_get_pci(sdev, arg); 436 default: 437 if (sdev->host->hostt->ioctl) 438 return sdev->host->hostt->ioctl(sdev, cmd, arg); 439 } 440 return -EINVAL; 441 } 442 EXPORT_SYMBOL(scsi_ioctl); 443 444 /* 445 * the scsi_nonblock_ioctl() function is designed for ioctls which may 446 * be executed even if the device is in recovery. 447 */ 448 int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd, 449 void __user *arg, struct file *filp) 450 { 451 int val, result; 452 453 /* The first set of iocts may be executed even if we're doing 454 * error processing, as long as the device was opened 455 * non-blocking */ 456 if (filp && filp->f_flags & O_NONBLOCK) { 457 if (scsi_host_in_recovery(sdev->host)) 458 return -ENODEV; 459 } else if (!scsi_block_when_processing_errors(sdev)) 460 return -ENODEV; 461 462 switch (cmd) { 463 case SG_SCSI_RESET: 464 result = get_user(val, (int __user *)arg); 465 if (result) 466 return result; 467 if (val == SG_SCSI_RESET_NOTHING) 468 return 0; 469 switch (val) { 470 case SG_SCSI_RESET_DEVICE: 471 val = SCSI_TRY_RESET_DEVICE; 472 break; 473 case SG_SCSI_RESET_BUS: 474 val = SCSI_TRY_RESET_BUS; 475 break; 476 case SG_SCSI_RESET_HOST: 477 val = SCSI_TRY_RESET_HOST; 478 break; 479 default: 480 return -EINVAL; 481 } 482 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) 483 return -EACCES; 484 return (scsi_reset_provider(sdev, val) == 485 SUCCESS) ? 0 : -EIO; 486 } 487 return -ENODEV; 488 } 489 EXPORT_SYMBOL(scsi_nonblockable_ioctl); 490