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                         printk(KERN_INFO "ioctl_internal_command: <%d %d %d "
 126                                "%d> return code = %x\n",
 127                                sdev->host->host_no,
 128                                sdev->channel,
 129                                sdev->id,
 130                                sdev->lun,
 131                                result);
 132                         scsi_print_sense_hdr("   ", &sshdr);
 133                         break;
 134                 }
 135         }
 136
 137         SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
 138         return result;
 139 }
 140
 141 int scsi_set_medium_removal(struct scsi_device *sdev, char state)
 142 {
 143         char scsi_cmd[MAX_COMMAND_SIZE];
 144         int ret;
 145
 146         if (!sdev->removable || !sdev->lockable)
 147                return 0;
 148
 149         scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 150         scsi_cmd[1] = 0;
 151         scsi_cmd[2] = 0;
 152         scsi_cmd[3] = 0;
 153         scsi_cmd[4] = state;
 154         scsi_cmd[5] = 0;
 155
 156         ret = ioctl_internal_command(sdev, scsi_cmd,
 157                         IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
 158         if (ret == 0)
 159                 sdev->locked = (state == SCSI_REMOVAL_PREVENT);
 160         return ret;
 161 }
 162 EXPORT_SYMBOL(scsi_set_medium_removal);
 163
 164 /*
 165  * This interface is deprecated - users should use the scsi generic (sg)
 166  * interface instead, as this is a more flexible approach to performing
 167  * generic SCSI commands on a device.
 168  *
 169  * The structure that we are passed should look like:
 170  *
 171  * struct sdata {
 172  *  unsigned int inlen;      [i] Length of data to be written to device
 173  *  unsigned int outlen;     [i] Length of data to be read from device
 174  *  unsigned char cmd[x];    [i] SCSI command (6 <= x <= 12).
 175  *                           [o] Data read from device starts here.
 176  *                           [o] On error, sense buffer starts here.
 177  *  unsigned char wdata[y];  [i] Data written to device starts here.
 178  * };
 179  * Notes:
 180  *   -  The SCSI command length is determined by examining the 1st byte
 181  *      of the given command. There is no way to override this.
 182  *   -  Data transfers are limited to PAGE_SIZE (4K on i386, 8K on alpha).
 183  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 184  *      accommodate the sense buffer when an error occurs.
 185  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 186  *      old code will not be surprised.
 187  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 188  *      a negative return and the Unix error code in 'errno'.
 189  *      If the SCSI command succeeds then 0 is returned.
 190  *      Positive numbers returned are the compacted SCSI error codes (4
 191  *      bytes in one int) where the lowest byte is the SCSI status.
 192  *      See the drivers/scsi/scsi.h file for more information on this.
 193  *
 194  */
 195 #define OMAX_SB_LEN 16          /* Old sense buffer length */
 196
 197 int scsi_ioctl_send_command(struct scsi_device *sdev,
 198                             struct scsi_ioctl_command __user *sic)
 199 {
 200         char *buf;
 201         unsigned char cmd[MAX_COMMAND_SIZE];
 202         unsigned char sense[SCSI_SENSE_BUFFERSIZE];
 203         char __user *cmd_in;
 204         unsigned char opcode;
 205         unsigned int inlen, outlen, cmdlen;
 206         unsigned int needed, buf_needed;
 207         int timeout, retries, result;
 208         int data_direction;
 209         gfp_t gfp_mask = GFP_KERNEL;
 210
 211         if (!sic)
 212                 return -EINVAL;
 213
 214         if (sdev->host->unchecked_isa_dma)
 215                 gfp_mask |= GFP_DMA;
 216
 217         /*
 218          * Verify that we can read at least this much.
 219          */
 220         if (!access_ok(VERIFY_READ, sic, sizeof(Scsi_Ioctl_Command)))
 221                 return -EFAULT;
 222
 223         if(__get_user(inlen, &sic->inlen))
 224                 return -EFAULT;
 225
 226         if(__get_user(outlen, &sic->outlen))
 227                 return -EFAULT;
 228
 229         /*
 230          * We do not transfer more than MAX_BUF with this interface.
 231          * If the user needs to transfer more data than this, they
 232          * should use scsi_generics (sg) instead.
 233          */
 234         if (inlen > MAX_BUF)
 235                 return -EINVAL;
 236         if (outlen > MAX_BUF)
 237                 return -EINVAL;
 238
 239         cmd_in = sic->data;
 240         if(get_user(opcode, cmd_in))
 241                 return -EFAULT;
 242
 243         needed = buf_needed = (inlen > outlen ? inlen : outlen);
 244         if (buf_needed) {
 245                 buf_needed = (buf_needed + 511) & ~511;
 246                 if (buf_needed > MAX_BUF)
 247                         buf_needed = MAX_BUF;
 248                 buf = kmalloc(buf_needed, gfp_mask);
 249                 if (!buf)
 250                         return -ENOMEM;
 251                 memset(buf, 0, buf_needed);
 252                 if (inlen == 0) {
 253                         data_direction = DMA_FROM_DEVICE;
 254                 } else if (outlen == 0 ) {
 255                         data_direction = DMA_TO_DEVICE;
 256                 } else {
 257                         /*
 258                          * Can this ever happen?
 259                          */
 260                         data_direction = DMA_BIDIRECTIONAL;
 261                 }
 262
 263         } else {
 264                 buf = NULL;
 265                 data_direction = DMA_NONE;
 266         }
 267
 268         /*
 269          * Obtain the command from the user's address space.
 270          */
 271         cmdlen = COMMAND_SIZE(opcode);
 272
 273         result = -EFAULT;
 274
 275         if (!access_ok(VERIFY_READ, cmd_in, cmdlen + inlen))
 276                 goto error;
 277
 278         if(__copy_from_user(cmd, cmd_in, cmdlen))
 279                 goto error;
 280
 281         /*
 282          * Obtain the data to be sent to the device (if any).
 283          */
 284
 285         if(copy_from_user(buf, cmd_in + cmdlen, inlen))
 286                 goto error;
 287
 288         switch (opcode) {
 289         case SEND_DIAGNOSTIC:
 290         case FORMAT_UNIT:
 291                 timeout = FORMAT_UNIT_TIMEOUT;
 292                 retries = 1;
 293                 break;
 294         case START_STOP:
 295                 timeout = START_STOP_TIMEOUT;
 296                 retries = NORMAL_RETRIES;
 297                 break;
 298         case MOVE_MEDIUM:
 299                 timeout = MOVE_MEDIUM_TIMEOUT;
 300                 retries = NORMAL_RETRIES;
 301                 break;
 302         case READ_ELEMENT_STATUS:
 303                 timeout = READ_ELEMENT_STATUS_TIMEOUT;
 304                 retries = NORMAL_RETRIES;
 305                 break;
 306         case READ_DEFECT_DATA:
 307                 timeout = READ_DEFECT_DATA_TIMEOUT;
 308                 retries = 1;
 309                 break;
 310         default:
 311                 timeout = IOCTL_NORMAL_TIMEOUT;
 312                 retries = NORMAL_RETRIES;
 313                 break;
 314         }
 315
 316         result = scsi_execute(sdev, cmd, data_direction, buf, needed,
 317                               sense, timeout, retries, 0);
 318
 319         /*
 320          * If there was an error condition, pass the info back to the user.
 321          */
 322         if (result) {
 323                 int sb_len = sizeof(*sense);
 324
 325                 sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len;
 326                 if (copy_to_user(cmd_in, sense, sb_len))
 327                         result = -EFAULT;
 328         } else {
 329                 if (copy_to_user(cmd_in, buf, outlen))
 330                         result = -EFAULT;
 331         }
 332
 333 error:
 334         kfree(buf);
 335         return result;
 336 }
 337 EXPORT_SYMBOL(scsi_ioctl_send_command);
 338
 339 /*
 340  * The scsi_ioctl_get_pci() function places into arg the value
 341  * pci_dev::slot_name (8 characters) for the PCI device (if any).
 342  * Returns: 0 on success
 343  *          -ENXIO if there isn't a PCI device pointer
 344  *                 (could be because the SCSI driver hasn't been
 345  *                  updated yet, or because it isn't a SCSI
 346  *                  device)
 347  *          any copy_to_user() error on failure there
 348  */
 349 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 350 {
 351         struct device *dev = scsi_get_device(sdev->host);
 352
 353         if (!dev)
 354                 return -ENXIO;
 355         return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0;
 356 }
 357
 358
 359 /*
 360  * the scsi_ioctl() function differs from most ioctls in that it does
 361  * not take a major/minor number as the dev field.  Rather, it takes
 362  * a pointer to a scsi_devices[] element, a structure.
 363  */
 364 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 365 {
 366         char scsi_cmd[MAX_COMMAND_SIZE];
 367
 368         /* No idea how this happens.... */
 369         if (!sdev)
 370                 return -ENXIO;
 371
 372         /*
 373          * If we are in the middle of error recovery, don't let anyone
 374          * else try and use this device.  Also, if error recovery fails, it
 375          * may try and take the device offline, in which case all further
 376          * access to the device is prohibited.
 377          */
 378         if (!scsi_block_when_processing_errors(sdev))
 379                 return -ENODEV;
 380
 381         /* Check for deprecated ioctls ... all the ioctls which don't
 382          * follow the new unique numbering scheme are deprecated */
 383         switch (cmd) {
 384         case SCSI_IOCTL_SEND_COMMAND:
 385         case SCSI_IOCTL_TEST_UNIT_READY:
 386         case SCSI_IOCTL_BENCHMARK_COMMAND:
 387         case SCSI_IOCTL_SYNC:
 388         case SCSI_IOCTL_START_UNIT:
 389         case SCSI_IOCTL_STOP_UNIT:
 390                 printk(KERN_WARNING "program %s is using a deprecated SCSI "
 391                        "ioctl, please convert it to SG_IO\n", current->comm);
 392                 break;
 393         default:
 394                 break;
 395         }
 396
 397         switch (cmd) {
 398         case SCSI_IOCTL_GET_IDLUN:
 399                 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 400                         return -EFAULT;
 401
 402                 __put_user((sdev->id & 0xff)
 403                          + ((sdev->lun & 0xff) << 8)
 404                          + ((sdev->channel & 0xff) << 16)
 405                          + ((sdev->host->host_no & 0xff) << 24),
 406                          &((struct scsi_idlun __user *)arg)->dev_id);
 407                 __put_user(sdev->host->unique_id,
 408                          &((struct scsi_idlun __user *)arg)->host_unique_id);
 409                 return 0;
 410         case SCSI_IOCTL_GET_BUS_NUMBER:
 411                 return put_user(sdev->host->host_no, (int __user *)arg);
 412         case SCSI_IOCTL_PROBE_HOST:
 413                 return ioctl_probe(sdev->host, arg);
 414         case SCSI_IOCTL_SEND_COMMAND:
 415                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 416                         return -EACCES;
 417                 return scsi_ioctl_send_command(sdev, arg);
 418         case SCSI_IOCTL_DOORLOCK:
 419                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 420         case SCSI_IOCTL_DOORUNLOCK:
 421                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 422         case SCSI_IOCTL_TEST_UNIT_READY:
 423                 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 424                                             NORMAL_RETRIES);
 425         case SCSI_IOCTL_START_UNIT:
 426                 scsi_cmd[0] = START_STOP;
 427                 scsi_cmd[1] = 0;
 428                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 429                 scsi_cmd[4] = 1;
 430                 return ioctl_internal_command(sdev, scsi_cmd,
 431                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 432         case SCSI_IOCTL_STOP_UNIT:
 433                 scsi_cmd[0] = START_STOP;
 434                 scsi_cmd[1] = 0;
 435                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 436                 scsi_cmd[4] = 0;
 437                 return ioctl_internal_command(sdev, scsi_cmd,
 438                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 439         case SCSI_IOCTL_GET_PCI:
 440                 return scsi_ioctl_get_pci(sdev, arg);
 441         default:
 442                 if (sdev->host->hostt->ioctl)
 443                         return sdev->host->hostt->ioctl(sdev, cmd, arg);
 444         }
 445         return -EINVAL;
 446 }
 447 EXPORT_SYMBOL(scsi_ioctl);
 448
 449 /*
 450  * the scsi_nonblock_ioctl() function is designed for ioctls which may
 451  * be executed even if the device is in recovery.
 452  */
 453 int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
 454                             void __user *arg, struct file *filp)
 455 {
 456         int val, result;
 457
 458         /* The first set of iocts may be executed even if we're doing
 459          * error processing, as long as the device was opened
 460          * non-blocking */
 461         if (filp && filp->f_flags & O_NONBLOCK) {
 462                 if (scsi_host_in_recovery(sdev->host))
 463                         return -ENODEV;
 464         } else if (!scsi_block_when_processing_errors(sdev))
 465                 return -ENODEV;
 466
 467         switch (cmd) {
 468         case SG_SCSI_RESET:
 469                 result = get_user(val, (int __user *)arg);
 470                 if (result)
 471                         return result;
 472                 if (val == SG_SCSI_RESET_NOTHING)
 473                         return 0;
 474                 switch (val) {
 475                 case SG_SCSI_RESET_DEVICE:
 476                         val = SCSI_TRY_RESET_DEVICE;
 477                         break;
 478                 case SG_SCSI_RESET_BUS:
 479                         val = SCSI_TRY_RESET_BUS;
 480                         break;
 481                 case SG_SCSI_RESET_HOST:
 482                         val = SCSI_TRY_RESET_HOST;
 483                         break;
 484                 default:
 485                         return -EINVAL;
 486                 }
 487                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 488                         return -EACCES;
 489                 return (scsi_reset_provider(sdev, val) ==
 490                         SUCCESS) ? 0 : -EIO;
 491         }
 492         return -ENODEV;
 493 }
 494 EXPORT_SYMBOL(scsi_nonblockable_ioctl);