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
  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);