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 = kmalloc(buf_needed, gfp_mask);
 245                 if (!buf)
 246                         return -ENOMEM;
 247                 memset(buf, 0, buf_needed);
 248                 if (inlen == 0) {
 249                         data_direction = DMA_FROM_DEVICE;
 250                 } else if (outlen == 0 ) {
 251                         data_direction = DMA_TO_DEVICE;
 252                 } else {
 253                         /*
 254                          * Can this ever happen?
 255                          */
 256                         data_direction = DMA_BIDIRECTIONAL;
 257                 }
 258
 259         } else {
 260                 buf = NULL;
 261                 data_direction = DMA_NONE;
 262         }
 263
 264         /*
 265          * Obtain the command from the user's address space.
 266          */
 267         cmdlen = COMMAND_SIZE(opcode);
 268
 269         result = -EFAULT;
 270
 271         if (!access_ok(VERIFY_READ, cmd_in, cmdlen + inlen))
 272                 goto error;
 273
 274         if(__copy_from_user(cmd, cmd_in, cmdlen))
 275                 goto error;
 276
 277         /*
 278          * Obtain the data to be sent to the device (if any).
 279          */
 280
 281         if(inlen && copy_from_user(buf, cmd_in + cmdlen, inlen))
 282                 goto error;
 283
 284         switch (opcode) {
 285         case SEND_DIAGNOSTIC:
 286         case FORMAT_UNIT:
 287                 timeout = FORMAT_UNIT_TIMEOUT;
 288                 retries = 1;
 289                 break;
 290         case START_STOP:
 291                 timeout = START_STOP_TIMEOUT;
 292                 retries = NORMAL_RETRIES;
 293                 break;
 294         case MOVE_MEDIUM:
 295                 timeout = MOVE_MEDIUM_TIMEOUT;
 296                 retries = NORMAL_RETRIES;
 297                 break;
 298         case READ_ELEMENT_STATUS:
 299                 timeout = READ_ELEMENT_STATUS_TIMEOUT;
 300                 retries = NORMAL_RETRIES;
 301                 break;
 302         case READ_DEFECT_DATA:
 303                 timeout = READ_DEFECT_DATA_TIMEOUT;
 304                 retries = 1;
 305                 break;
 306         default:
 307                 timeout = IOCTL_NORMAL_TIMEOUT;
 308                 retries = NORMAL_RETRIES;
 309                 break;
 310         }
 311
 312         result = scsi_execute(sdev, cmd, data_direction, buf, needed,
 313                               sense, timeout, retries, 0);
 314
 315         /*
 316          * If there was an error condition, pass the info back to the user.
 317          */
 318         if (result) {
 319                 int sb_len = sizeof(*sense);
 320
 321                 sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len;
 322                 if (copy_to_user(cmd_in, sense, sb_len))
 323                         result = -EFAULT;
 324         } else {
 325                 if (outlen && copy_to_user(cmd_in, buf, outlen))
 326                         result = -EFAULT;
 327         }
 328
 329 error:
 330         kfree(buf);
 331         return result;
 332 }
 333 EXPORT_SYMBOL(scsi_ioctl_send_command);
 334
 335 /*
 336  * The scsi_ioctl_get_pci() function places into arg the value
 337  * pci_dev::slot_name (8 characters) for the PCI device (if any).
 338  * Returns: 0 on success
 339  *          -ENXIO if there isn't a PCI device pointer
 340  *                 (could be because the SCSI driver hasn't been
 341  *                  updated yet, or because it isn't a SCSI
 342  *                  device)
 343  *          any copy_to_user() error on failure there
 344  */
 345 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 346 {
 347         struct device *dev = scsi_get_device(sdev->host);
 348
 349         if (!dev)
 350                 return -ENXIO;
 351         return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0;
 352 }
 353
 354
 355 /*
 356  * the scsi_ioctl() function differs from most ioctls in that it does
 357  * not take a major/minor number as the dev field.  Rather, it takes
 358  * a pointer to a scsi_devices[] element, a structure.
 359  */
 360 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 361 {
 362         char scsi_cmd[MAX_COMMAND_SIZE];
 363
 364         /* No idea how this happens.... */
 365         if (!sdev)
 366                 return -ENXIO;
 367
 368         /*
 369          * If we are in the middle of error recovery, don't let anyone
 370          * else try and use this device.  Also, if error recovery fails, it
 371          * may try and take the device offline, in which case all further
 372          * access to the device is prohibited.
 373          */
 374         if (!scsi_block_when_processing_errors(sdev))
 375                 return -ENODEV;
 376
 377         /* Check for deprecated ioctls ... all the ioctls which don't
 378          * follow the new unique numbering scheme are deprecated */
 379         switch (cmd) {
 380         case SCSI_IOCTL_SEND_COMMAND:
 381         case SCSI_IOCTL_TEST_UNIT_READY:
 382         case SCSI_IOCTL_BENCHMARK_COMMAND:
 383         case SCSI_IOCTL_SYNC:
 384         case SCSI_IOCTL_START_UNIT:
 385         case SCSI_IOCTL_STOP_UNIT:
 386                 printk(KERN_WARNING "program %s is using a deprecated SCSI "
 387                        "ioctl, please convert it to SG_IO\n", current->comm);
 388                 break;
 389         default:
 390                 break;
 391         }
 392
 393         switch (cmd) {
 394         case SCSI_IOCTL_GET_IDLUN:
 395                 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 396                         return -EFAULT;
 397
 398                 __put_user((sdev->id & 0xff)
 399                          + ((sdev->lun & 0xff) << 8)
 400                          + ((sdev->channel & 0xff) << 16)
 401                          + ((sdev->host->host_no & 0xff) << 24),
 402                          &((struct scsi_idlun __user *)arg)->dev_id);
 403                 __put_user(sdev->host->unique_id,
 404                          &((struct scsi_idlun __user *)arg)->host_unique_id);
 405                 return 0;
 406         case SCSI_IOCTL_GET_BUS_NUMBER:
 407                 return put_user(sdev->host->host_no, (int __user *)arg);
 408         case SCSI_IOCTL_PROBE_HOST:
 409                 return ioctl_probe(sdev->host, arg);
 410         case SCSI_IOCTL_SEND_COMMAND:
 411                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 412                         return -EACCES;
 413                 return scsi_ioctl_send_command(sdev, arg);
 414         case SCSI_IOCTL_DOORLOCK:
 415                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 416         case SCSI_IOCTL_DOORUNLOCK:
 417                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 418         case SCSI_IOCTL_TEST_UNIT_READY:
 419                 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 420                                             NORMAL_RETRIES);
 421         case SCSI_IOCTL_START_UNIT:
 422                 scsi_cmd[0] = START_STOP;
 423                 scsi_cmd[1] = 0;
 424                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 425                 scsi_cmd[4] = 1;
 426                 return ioctl_internal_command(sdev, scsi_cmd,
 427                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 428         case SCSI_IOCTL_STOP_UNIT:
 429                 scsi_cmd[0] = START_STOP;
 430                 scsi_cmd[1] = 0;
 431                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 432                 scsi_cmd[4] = 0;
 433                 return ioctl_internal_command(sdev, scsi_cmd,
 434                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 435         case SCSI_IOCTL_GET_PCI:
 436                 return scsi_ioctl_get_pci(sdev, arg);
 437         default:
 438                 if (sdev->host->hostt->ioctl)
 439                         return sdev->host->hostt->ioctl(sdev, cmd, arg);
 440         }
 441         return -EINVAL;
 442 }
 443 EXPORT_SYMBOL(scsi_ioctl);
 444
 445 /*
 446  * the scsi_nonblock_ioctl() function is designed for ioctls which may
 447  * be executed even if the device is in recovery.
 448  */
 449 int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
 450                             void __user *arg, struct file *filp)
 451 {
 452         int val, result;
 453
 454         /* The first set of iocts may be executed even if we're doing
 455          * error processing, as long as the device was opened
 456          * non-blocking */
 457         if (filp && filp->f_flags & O_NONBLOCK) {
 458                 if (scsi_host_in_recovery(sdev->host))
 459                         return -ENODEV;
 460         } else if (!scsi_block_when_processing_errors(sdev))
 461                 return -ENODEV;
 462
 463         switch (cmd) {
 464         case SG_SCSI_RESET:
 465                 result = get_user(val, (int __user *)arg);
 466                 if (result)
 467                         return result;
 468                 if (val == SG_SCSI_RESET_NOTHING)
 469                         return 0;
 470                 switch (val) {
 471                 case SG_SCSI_RESET_DEVICE:
 472                         val = SCSI_TRY_RESET_DEVICE;
 473                         break;
 474                 case SG_SCSI_RESET_BUS:
 475                         val = SCSI_TRY_RESET_BUS;
 476                         break;
 477                 case SG_SCSI_RESET_HOST:
 478                         val = SCSI_TRY_RESET_HOST;
 479                         break;
 480                 default:
 481                         return -EINVAL;
 482                 }
 483                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 484                         return -EACCES;
 485                 return (scsi_reset_provider(sdev, val) ==
 486                         SUCCESS) ? 0 : -EIO;
 487         }
 488         return -ENODEV;
 489 }
 490 EXPORT_SYMBOL(scsi_nonblockable_ioctl);