drivers/scsi/scsi_ioctl.c

   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 #define FORMAT_UNIT_TIMEOUT             (2 * 60 * 60 * HZ)
  31 #define START_STOP_TIMEOUT              (60 * HZ)
  32 #define MOVE_MEDIUM_TIMEOUT             (5 * 60 * HZ)
  33 #define READ_ELEMENT_STATUS_TIMEOUT     (5 * 60 * HZ)
  34 #define READ_DEFECT_DATA_TIMEOUT        (60 * HZ )  /* ZIP-250 on parallel port takes as long! */
  35
  36 #define MAX_BUF PAGE_SIZE
  37
  38 /*
  39  * If we are told to probe a host, we will return 0 if  the host is not
  40  * present, 1 if the host is present, and will return an identifying
  41  * string at *arg, if arg is non null, filling to the length stored at
  42  * (int *) arg
  43  */
  44
  45 static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
  46 {
  47         unsigned int len, slen;
  48         const char *string;
  49         int temp = host->hostt->present;
  50
  51         if (temp && buffer) {
  52                 if (get_user(len, (unsigned int __user *) buffer))
  53                         return -EFAULT;
  54
  55                 if (host->hostt->info)
  56                         string = host->hostt->info(host);
  57                 else
  58                         string = host->hostt->name;
  59                 if (string) {
  60                         slen = strlen(string);
  61                         if (len > slen)
  62                                 len = slen + 1;
  63                         if (copy_to_user(buffer, string, len))
  64                                 return -EFAULT;
  65                 }
  66         }
  67         return temp;
  68 }
  69
  70 /*
  71
  72  * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
  73  * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES  variables are used.
  74  *
  75  * dev is the SCSI device struct ptr, *(int *) arg is the length of the
  76  * input data, if any, not including the command string & counts,
  77  * *((int *)arg + 1) is the output buffer size in bytes.
  78  *
  79  * *(char *) ((int *) arg)[2] the actual command byte.
  80  *
  81  * Note that if more than MAX_BUF bytes are requested to be transferred,
  82  * the ioctl will fail with error EINVAL.
  83  *
  84  * This size *does not* include the initial lengths that were passed.
  85  *
  86  * The SCSI command is read from the memory location immediately after the
  87  * length words, and the input data is right after the command.  The SCSI
  88  * routines know the command size based on the opcode decode.
  89  *
  90  * The output area is then filled in starting from the command byte.
  91  */
  92
  93 static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
  94                                   int timeout, int retries)
  95 {
  96         struct scsi_request *sreq;
  97         int result;
  98         struct scsi_sense_hdr sshdr;
  99
 100         SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", *cmd));
 101
 102         sreq = scsi_allocate_request(sdev, GFP_KERNEL);
 103         if (!sreq) {
 104                 printk(KERN_WARNING "SCSI internal ioctl failed, no memory\n");
 105                 return -ENOMEM;
 106         }
 107
 108         sreq->sr_data_direction = DMA_NONE;
 109         scsi_wait_req(sreq, cmd, NULL, 0, timeout, retries);
 110
 111         SCSI_LOG_IOCTL(2, printk("Ioctl returned  0x%x\n", sreq->sr_result));
 112
 113         if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) &&
 114             (scsi_request_normalize_sense(sreq, &sshdr))) {
 115                 switch (sshdr.sense_key) {
 116                 case ILLEGAL_REQUEST:
 117                         if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
 118                                 sdev->lockable = 0;
 119                         else
 120                                 printk(KERN_INFO "ioctl_internal_command: "
 121                                        "ILLEGAL REQUEST asc=0x%x ascq=0x%x\n",
 122                                        sshdr.asc, sshdr.ascq);
 123                         break;
 124                 case NOT_READY: /* This happens if there is no disc in drive */
 125                         if (sdev->removable && (cmd[0] != TEST_UNIT_READY)) {
 126                                 printk(KERN_INFO "Device not ready. Make sure"
 127                                        " there is a disc in the drive.\n");
 128                                 break;
 129                         }
 130                 case UNIT_ATTENTION:
 131                         if (sdev->removable) {
 132                                 sdev->changed = 1;
 133                                 sreq->sr_result = 0;    /* This is no longer considered an error */
 134                                 break;
 135                         }
 136                 default:        /* Fall through for non-removable media */
 137                         printk(KERN_INFO "ioctl_internal_command: <%d %d %d "
 138                                "%d> return code = %x\n",
 139                                sdev->host->host_no,
 140                                sdev->channel,
 141                                sdev->id,
 142                                sdev->lun,
 143                                sreq->sr_result);
 144                         scsi_print_req_sense("   ", sreq);
 145                         break;
 146                 }
 147         }
 148
 149         result = sreq->sr_result;
 150         SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
 151         scsi_release_request(sreq);
 152         return result;
 153 }
 154
 155 int scsi_set_medium_removal(struct scsi_device *sdev, char state)
 156 {
 157         char scsi_cmd[MAX_COMMAND_SIZE];
 158         int ret;
 159
 160         if (!sdev->removable || !sdev->lockable)
 161                return 0;
 162
 163         scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 164         scsi_cmd[1] = 0;
 165         scsi_cmd[2] = 0;
 166         scsi_cmd[3] = 0;
 167         scsi_cmd[4] = state;
 168         scsi_cmd[5] = 0;
 169
 170         ret = ioctl_internal_command(sdev, scsi_cmd,
 171                         IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
 172         if (ret == 0)
 173                 sdev->locked = (state == SCSI_REMOVAL_PREVENT);
 174         return ret;
 175 }
 176 EXPORT_SYMBOL(scsi_set_medium_removal);
 177
 178 /*
 179  * This interface is deprecated - users should use the scsi generic (sg)
 180  * interface instead, as this is a more flexible approach to performing
 181  * generic SCSI commands on a device.
 182  *
 183  * The structure that we are passed should look like:
 184  *
 185  * struct sdata {
 186  *  unsigned int inlen;      [i] Length of data to be written to device
 187  *  unsigned int outlen;     [i] Length of data to be read from device
 188  *  unsigned char cmd[x];    [i] SCSI command (6 <= x <= 12).
 189  *                           [o] Data read from device starts here.
 190  *                           [o] On error, sense buffer starts here.
 191  *  unsigned char wdata[y];  [i] Data written to device starts here.
 192  * };
 193  * Notes:
 194  *   -  The SCSI command length is determined by examining the 1st byte
 195  *      of the given command. There is no way to override this.
 196  *   -  Data transfers are limited to PAGE_SIZE (4K on i386, 8K on alpha).
 197  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 198  *      accommodate the sense buffer when an error occurs.
 199  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 200  *      old code will not be surprised.
 201  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 202  *      a negative return and the Unix error code in 'errno'.
 203  *      If the SCSI command succeeds then 0 is returned.
 204  *      Positive numbers returned are the compacted SCSI error codes (4
 205  *      bytes in one int) where the lowest byte is the SCSI status.
 206  *      See the drivers/scsi/scsi.h file for more information on this.
 207  *
 208  */
 209 #define OMAX_SB_LEN 16          /* Old sense buffer length */
 210
 211 int scsi_ioctl_send_command(struct scsi_device *sdev,
 212                             struct scsi_ioctl_command __user *sic)
 213 {
 214         char *buf;
 215         unsigned char cmd[MAX_COMMAND_SIZE];
 216         char __user *cmd_in;
 217         struct scsi_request *sreq;
 218         unsigned char opcode;
 219         unsigned int inlen, outlen, cmdlen;
 220         unsigned int needed, buf_needed;
 221         int timeout, retries, result;
 222         int data_direction, gfp_mask = GFP_KERNEL;
 223
 224         if (!sic)
 225                 return -EINVAL;
 226
 227         if (sdev->host->unchecked_isa_dma)
 228                 gfp_mask |= GFP_DMA;
 229
 230         /*
 231          * Verify that we can read at least this much.
 232          */
 233         if (!access_ok(VERIFY_READ, sic, sizeof(Scsi_Ioctl_Command)))
 234                 return -EFAULT;
 235
 236         if(__get_user(inlen, &sic->inlen))
 237                 return -EFAULT;
 238
 239         if(__get_user(outlen, &sic->outlen))
 240                 return -EFAULT;
 241
 242         /*
 243          * We do not transfer more than MAX_BUF with this interface.
 244          * If the user needs to transfer more data than this, they
 245          * should use scsi_generics (sg) instead.
 246          */
 247         if (inlen > MAX_BUF)
 248                 return -EINVAL;
 249         if (outlen > MAX_BUF)
 250                 return -EINVAL;
 251
 252         cmd_in = sic->data;
 253         if(get_user(opcode, cmd_in))
 254                 return -EFAULT;
 255
 256         needed = buf_needed = (inlen > outlen ? inlen : outlen);
 257         if (buf_needed) {
 258                 buf_needed = (buf_needed + 511) & ~511;
 259                 if (buf_needed > MAX_BUF)
 260                         buf_needed = MAX_BUF;
 261                 buf = kmalloc(buf_needed, gfp_mask);
 262                 if (!buf)
 263                         return -ENOMEM;
 264                 memset(buf, 0, buf_needed);
 265                 if (inlen == 0) {
 266                         data_direction = DMA_FROM_DEVICE;
 267                 } else if (outlen == 0 ) {
 268                         data_direction = DMA_TO_DEVICE;
 269                 } else {
 270                         /*
 271                          * Can this ever happen?
 272                          */
 273                         data_direction = DMA_BIDIRECTIONAL;
 274                 }
 275
 276         } else {
 277                 buf = NULL;
 278                 data_direction = DMA_NONE;
 279         }
 280
 281         /*
 282          * Obtain the command from the user's address space.
 283          */
 284         cmdlen = COMMAND_SIZE(opcode);
 285
 286         result = -EFAULT;
 287
 288         if (!access_ok(VERIFY_READ, cmd_in, cmdlen + inlen))
 289                 goto error;
 290
 291         if(__copy_from_user(cmd, cmd_in, cmdlen))
 292                 goto error;
 293
 294         /*
 295          * Obtain the data to be sent to the device (if any).
 296          */
 297
 298         if(copy_from_user(buf, cmd_in + cmdlen, inlen))
 299                 goto error;
 300
 301         switch (opcode) {
 302         case SEND_DIAGNOSTIC:
 303         case FORMAT_UNIT:
 304                 timeout = FORMAT_UNIT_TIMEOUT;
 305                 retries = 1;
 306                 break;
 307         case START_STOP:
 308                 timeout = START_STOP_TIMEOUT;
 309                 retries = NORMAL_RETRIES;
 310                 break;
 311         case MOVE_MEDIUM:
 312                 timeout = MOVE_MEDIUM_TIMEOUT;
 313                 retries = NORMAL_RETRIES;
 314                 break;
 315         case READ_ELEMENT_STATUS:
 316                 timeout = READ_ELEMENT_STATUS_TIMEOUT;
 317                 retries = NORMAL_RETRIES;
 318                 break;
 319         case READ_DEFECT_DATA:
 320                 timeout = READ_DEFECT_DATA_TIMEOUT;
 321                 retries = 1;
 322                 break;
 323         default:
 324                 timeout = IOCTL_NORMAL_TIMEOUT;
 325                 retries = NORMAL_RETRIES;
 326                 break;
 327         }
 328
 329         sreq = scsi_allocate_request(sdev, GFP_KERNEL);
 330         if (!sreq) {
 331                 result = -EINTR;
 332                 goto error;
 333         }
 334
 335         sreq->sr_data_direction = data_direction;
 336         scsi_wait_req(sreq, cmd, buf, needed, timeout, retries);
 337
 338         /*
 339          * If there was an error condition, pass the info back to the user.
 340          */
 341         result = sreq->sr_result;
 342         if (result) {
 343                 int sb_len = sizeof(sreq->sr_sense_buffer);
 344
 345                 sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len;
 346                 if (copy_to_user(cmd_in, sreq->sr_sense_buffer, sb_len))
 347                         result = -EFAULT;
 348         } else {
 349                 if (copy_to_user(cmd_in, buf, outlen))
 350                         result = -EFAULT;
 351         }
 352
 353         scsi_release_request(sreq);
 354 error:
 355         kfree(buf);
 356         return result;
 357 }
 358 EXPORT_SYMBOL(scsi_ioctl_send_command);
 359
 360 /*
 361  * The scsi_ioctl_get_pci() function places into arg the value
 362  * pci_dev::slot_name (8 characters) for the PCI device (if any).
 363  * Returns: 0 on success
 364  *          -ENXIO if there isn't a PCI device pointer
 365  *                 (could be because the SCSI driver hasn't been
 366  *                  updated yet, or because it isn't a SCSI
 367  *                  device)
 368  *          any copy_to_user() error on failure there
 369  */
 370 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 371 {
 372         struct device *dev = scsi_get_device(sdev->host);
 373
 374         if (!dev)
 375                 return -ENXIO;
 376         return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0;
 377 }
 378
 379
 380 /*
 381  * the scsi_ioctl() function differs from most ioctls in that it does
 382  * not take a major/minor number as the dev field.  Rather, it takes
 383  * a pointer to a scsi_devices[] element, a structure.
 384  */
 385 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 386 {
 387         char scsi_cmd[MAX_COMMAND_SIZE];
 388
 389         /* No idea how this happens.... */
 390         if (!sdev)
 391                 return -ENXIO;
 392
 393         /*
 394          * If we are in the middle of error recovery, don't let anyone
 395          * else try and use this device.  Also, if error recovery fails, it
 396          * may try and take the device offline, in which case all further
 397          * access to the device is prohibited.
 398          */
 399         if (!scsi_block_when_processing_errors(sdev))
 400                 return -ENODEV;
 401
 402         /* Check for deprecated ioctls ... all the ioctls which don't
 403          * follow the new unique numbering scheme are deprecated */
 404         switch (cmd) {
 405         case SCSI_IOCTL_SEND_COMMAND:
 406         case SCSI_IOCTL_TEST_UNIT_READY:
 407         case SCSI_IOCTL_BENCHMARK_COMMAND:
 408         case SCSI_IOCTL_SYNC:
 409         case SCSI_IOCTL_START_UNIT:
 410         case SCSI_IOCTL_STOP_UNIT:
 411                 printk(KERN_WARNING "program %s is using a deprecated SCSI "
 412                        "ioctl, please convert it to SG_IO\n", current->comm);
 413                 break;
 414         default:
 415                 break;
 416         }
 417
 418         switch (cmd) {
 419         case SCSI_IOCTL_GET_IDLUN:
 420                 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 421                         return -EFAULT;
 422
 423                 __put_user((sdev->id & 0xff)
 424                          + ((sdev->lun & 0xff) << 8)
 425                          + ((sdev->channel & 0xff) << 16)
 426                          + ((sdev->host->host_no & 0xff) << 24),
 427                          &((struct scsi_idlun __user *)arg)->dev_id);
 428                 __put_user(sdev->host->unique_id,
 429                          &((struct scsi_idlun __user *)arg)->host_unique_id);
 430                 return 0;
 431         case SCSI_IOCTL_GET_BUS_NUMBER:
 432                 return put_user(sdev->host->host_no, (int __user *)arg);
 433         case SCSI_IOCTL_PROBE_HOST:
 434                 return ioctl_probe(sdev->host, arg);
 435         case SCSI_IOCTL_SEND_COMMAND:
 436                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 437                         return -EACCES;
 438                 return scsi_ioctl_send_command(sdev, arg);
 439         case SCSI_IOCTL_DOORLOCK:
 440                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 441         case SCSI_IOCTL_DOORUNLOCK:
 442                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 443         case SCSI_IOCTL_TEST_UNIT_READY:
 444                 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 445                                             NORMAL_RETRIES);
 446         case SCSI_IOCTL_START_UNIT:
 447                 scsi_cmd[0] = START_STOP;
 448                 scsi_cmd[1] = 0;
 449                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 450                 scsi_cmd[4] = 1;
 451                 return ioctl_internal_command(sdev, scsi_cmd,
 452                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 453         case SCSI_IOCTL_STOP_UNIT:
 454                 scsi_cmd[0] = START_STOP;
 455                 scsi_cmd[1] = 0;
 456                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 457                 scsi_cmd[4] = 0;
 458                 return ioctl_internal_command(sdev, scsi_cmd,
 459                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 460         case SCSI_IOCTL_GET_PCI:
 461                 return scsi_ioctl_get_pci(sdev, arg);
 462         default:
 463                 if (sdev->host->hostt->ioctl)
 464                         return sdev->host->hostt->ioctl(sdev, cmd, arg);
 465         }
 466         return -EINVAL;
 467 }
 468 EXPORT_SYMBOL(scsi_ioctl);
 469
 470 /*
 471  * the scsi_nonblock_ioctl() function is designed for ioctls which may
 472  * be executed even if the device is in recovery.
 473  */
 474 int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
 475                             void __user *arg, struct file *filp)
 476 {
 477         int val, result;
 478
 479         /* The first set of iocts may be executed even if we're doing
 480          * error processing, as long as the device was opened
 481          * non-blocking */
 482         if (filp && filp->f_flags & O_NONBLOCK) {
 483                 if (test_bit(SHOST_RECOVERY,
 484                              &sdev->host->shost_state))
 485                         return -ENODEV;
 486         } else if (!scsi_block_when_processing_errors(sdev))
 487                 return -ENODEV;
 488
 489         switch (cmd) {
 490         case SG_SCSI_RESET:
 491                 result = get_user(val, (int __user *)arg);
 492                 if (result)
 493                         return result;
 494                 if (val == SG_SCSI_RESET_NOTHING)
 495                         return 0;
 496                 switch (val) {
 497                 case SG_SCSI_RESET_DEVICE:
 498                         val = SCSI_TRY_RESET_DEVICE;
 499                         break;
 500                 case SG_SCSI_RESET_BUS:
 501                         val = SCSI_TRY_RESET_BUS;
 502                         break;
 503                 case SG_SCSI_RESET_HOST:
 504                         val = SCSI_TRY_RESET_HOST;
 505                         break;
 506                 default:
 507                         return -EINVAL;
 508                 }
 509                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 510                         return -EACCES;
 511                 return (scsi_reset_provider(sdev, val) ==
 512                         SUCCESS) ? 0 : -EIO;
 513         }
 514         return -ENODEV;
 515 }
 516 EXPORT_SYMBOL(scsi_nonblockable_ioctl);