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
  24 #include "scsi_logging.h"
  25
  26 #define NORMAL_RETRIES                  5
  27 #define IOCTL_NORMAL_TIMEOUT                    (10 * HZ)
  28 #define FORMAT_UNIT_TIMEOUT             (2 * 60 * 60 * HZ)
  29 #define START_STOP_TIMEOUT              (60 * HZ)
  30 #define MOVE_MEDIUM_TIMEOUT             (5 * 60 * HZ)
  31 #define READ_ELEMENT_STATUS_TIMEOUT     (5 * 60 * HZ)
  32 #define READ_DEFECT_DATA_TIMEOUT        (60 * HZ )  /* ZIP-250 on parallel port takes as long! */
  33
  34 #define MAX_BUF PAGE_SIZE
  35
  36 /*
  37  * If we are told to probe a host, we will return 0 if  the host is not
  38  * present, 1 if the host is present, and will return an identifying
  39  * string at *arg, if arg is non null, filling to the length stored at
  40  * (int *) arg
  41  */
  42
  43 static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
  44 {
  45         unsigned int len, slen;
  46         const char *string;
  47         int temp = host->hostt->present;
  48
  49         if (temp && buffer) {
  50                 if (get_user(len, (unsigned int __user *) buffer))
  51                         return -EFAULT;
  52
  53                 if (host->hostt->info)
  54                         string = host->hostt->info(host);
  55                 else
  56                         string = host->hostt->name;
  57                 if (string) {
  58                         slen = strlen(string);
  59                         if (len > slen)
  60                                 len = slen + 1;
  61                         if (copy_to_user(buffer, string, len))
  62                                 return -EFAULT;
  63                 }
  64         }
  65         return temp;
  66 }
  67
  68 /*
  69
  70  * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
  71  * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES  variables are used.
  72  *
  73  * dev is the SCSI device struct ptr, *(int *) arg is the length of the
  74  * input data, if any, not including the command string & counts,
  75  * *((int *)arg + 1) is the output buffer size in bytes.
  76  *
  77  * *(char *) ((int *) arg)[2] the actual command byte.
  78  *
  79  * Note that if more than MAX_BUF bytes are requested to be transferred,
  80  * the ioctl will fail with error EINVAL.
  81  *
  82  * This size *does not* include the initial lengths that were passed.
  83  *
  84  * The SCSI command is read from the memory location immediately after the
  85  * length words, and the input data is right after the command.  The SCSI
  86  * routines know the command size based on the opcode decode.
  87  *
  88  * The output area is then filled in starting from the command byte.
  89  */
  90
  91 static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
  92                                   int timeout, int retries)
  93 {
  94         struct scsi_request *sreq;
  95         int result;
  96
  97         SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", *cmd));
  98
  99         sreq = scsi_allocate_request(sdev, GFP_KERNEL);
 100         if (!sreq) {
 101                 printk("SCSI internal ioctl failed, no memory\n");
 102                 return -ENOMEM;
 103         }
 104
 105         sreq->sr_data_direction = DMA_NONE;
 106         scsi_wait_req(sreq, cmd, NULL, 0, timeout, retries);
 107
 108         SCSI_LOG_IOCTL(2, printk("Ioctl returned  0x%x\n", sreq->sr_result));
 109
 110         if (driver_byte(sreq->sr_result)) {
 111                 switch (sreq->sr_sense_buffer[2] & 0xf) {
 112                 case ILLEGAL_REQUEST:
 113                         if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
 114                                 sdev->lockable = 0;
 115                         else
 116                                 printk("SCSI device (ioctl) reports ILLEGAL REQUEST.\n");
 117                         break;
 118                 case NOT_READY: /* This happens if there is no disc in drive */
 119                         if (sdev->removable && (cmd[0] != TEST_UNIT_READY)) {
 120                                 printk(KERN_INFO "Device not ready.  Make sure there is a disc in the drive.\n");
 121                                 break;
 122                         }
 123                 case UNIT_ATTENTION:
 124                         if (sdev->removable) {
 125                                 sdev->changed = 1;
 126                                 sreq->sr_result = 0;    /* This is no longer considered an error */
 127                                 break;
 128                         }
 129                 default:        /* Fall through for non-removable media */
 130 #if 0 //johnson remove 2008-01-10
 131                         printk("SCSI error: host %d id %d lun %d return code = %x\n",
 132                                sdev->host->host_no,
 133                                sdev->id,
 134                                sdev->lun,
 135                                sreq->sr_result);
 136                         printk("\tSense class %x, sense error %x, extended sense %x\n",
 137                                sense_class(sreq->sr_sense_buffer[0]),
 138                                sense_error(sreq->sr_sense_buffer[0]),
 139                                sreq->sr_sense_buffer[2] & 0xf);
 140 #endif
 141                 }
 142         }
 143
 144         result = sreq->sr_result;
 145         SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
 146         scsi_release_request(sreq);
 147         return result;
 148 }
 149
 150 int scsi_set_medium_removal(struct scsi_device *sdev, char state)
 151 {
 152         char scsi_cmd[MAX_COMMAND_SIZE];
 153         int ret;
 154
 155         if (!sdev->removable || !sdev->lockable)
 156                return 0;
 157
 158         scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 159         scsi_cmd[1] = 0;
 160         scsi_cmd[2] = 0;
 161         scsi_cmd[3] = 0;
 162         scsi_cmd[4] = state;
 163         scsi_cmd[5] = 0;
 164
 165         ret = ioctl_internal_command(sdev, scsi_cmd,
 166                         IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
 167         if (ret == 0)
 168                 sdev->locked = (state == SCSI_REMOVAL_PREVENT);
 169         return ret;
 170 }
 171
 172 /*
 173  * This interface is deprecated - users should use the scsi generic (sg)
 174  * interface instead, as this is a more flexible approach to performing
 175  * generic SCSI commands on a device.
 176  *
 177  * The structure that we are passed should look like:
 178  *
 179  * struct sdata {
 180  *  unsigned int inlen;      [i] Length of data to be written to device
 181  *  unsigned int outlen;     [i] Length of data to be read from device
 182  *  unsigned char cmd[x];    [i] SCSI command (6 <= x <= 12).
 183  *                           [o] Data read from device starts here.
 184  *                           [o] On error, sense buffer starts here.
 185  *  unsigned char wdata[y];  [i] Data written to device starts here.
 186  * };
 187  * Notes:
 188  *   -  The SCSI command length is determined by examining the 1st byte
 189  *      of the given command. There is no way to override this.
 190  *   -  Data transfers are limited to PAGE_SIZE (4K on i386, 8K on alpha).
 191  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 192  *      accommodate the sense buffer when an error occurs.
 193  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 194  *      old code will not be surprised.
 195  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 196  *      a negative return and the Unix error code in 'errno'.
 197  *      If the SCSI command succeeds then 0 is returned.
 198  *      Positive numbers returned are the compacted SCSI error codes (4
 199  *      bytes in one int) where the lowest byte is the SCSI status.
 200  *      See the drivers/scsi/scsi.h file for more information on this.
 201  *
 202  */
 203 #define OMAX_SB_LEN 16          /* Old sense buffer length */
 204
 205 int scsi_ioctl_send_command(struct scsi_device *sdev,
 206                             struct scsi_ioctl_command __user *sic)
 207 {
 208         char *buf;
 209         unsigned char cmd[MAX_COMMAND_SIZE];
 210         char __user *cmd_in;
 211         struct scsi_request *sreq;
 212         unsigned char opcode;
 213         unsigned int inlen, outlen, cmdlen;
 214         unsigned int needed, buf_needed;
 215         int timeout, retries, result;
 216         int data_direction, gfp_mask = GFP_KERNEL;
 217
 218         if (!sic)
 219                 return -EINVAL;
 220
 221         if (sdev->host->unchecked_isa_dma)
 222                 gfp_mask |= GFP_DMA;
 223
 224         /*
 225          * Verify that we can read at least this much.
 226          */
 227         if (verify_area(VERIFY_READ, sic, sizeof(Scsi_Ioctl_Command)))
 228                 return -EFAULT;
 229
 230         if(__get_user(inlen, &sic->inlen))
 231                 return -EFAULT;
 232
 233         if(__get_user(outlen, &sic->outlen))
 234                 return -EFAULT;
 235
 236         /*
 237          * We do not transfer more than MAX_BUF with this interface.
 238          * If the user needs to transfer more data than this, they
 239          * should use scsi_generics (sg) instead.
 240          */
 241         if (inlen > MAX_BUF)
 242                 return -EINVAL;
 243         if (outlen > MAX_BUF)
 244                 return -EINVAL;
 245
 246         cmd_in = sic->data;
 247         if(get_user(opcode, cmd_in))
 248                 return -EFAULT;
 249
 250         needed = buf_needed = (inlen > outlen ? inlen : outlen);
 251         if (buf_needed) {
 252                 buf_needed = (buf_needed + 511) & ~511;
 253                 if (buf_needed > MAX_BUF)
 254                         buf_needed = MAX_BUF;
 255                 buf = kmalloc(buf_needed, gfp_mask);
 256                 if (!buf)
 257                         return -ENOMEM;
 258                 memset(buf, 0, buf_needed);
 259                 if (inlen == 0) {
 260                         data_direction = DMA_FROM_DEVICE;
 261                 } else if (outlen == 0 ) {
 262                         data_direction = DMA_TO_DEVICE;
 263                 } else {
 264                         /*
 265                          * Can this ever happen?
 266                          */
 267                         data_direction = DMA_BIDIRECTIONAL;
 268                 }
 269
 270         } else {
 271                 buf = NULL;
 272                 data_direction = DMA_NONE;
 273         }
 274
 275         /*
 276          * Obtain the command from the user's address space.
 277          */
 278         cmdlen = COMMAND_SIZE(opcode);
 279
 280         result = -EFAULT;
 281
 282         if (verify_area(VERIFY_READ, cmd_in, cmdlen + inlen))
 283                 goto error;
 284
 285         if(__copy_from_user(cmd, cmd_in, cmdlen))
 286                 goto error;
 287
 288         /*
 289          * Obtain the data to be sent to the device (if any).
 290          */
 291
 292         if(copy_from_user(buf, cmd_in + cmdlen, inlen))
 293                 goto error;
 294
 295         switch (opcode) {
 296         case SEND_DIAGNOSTIC:
 297         case FORMAT_UNIT:
 298                 timeout = FORMAT_UNIT_TIMEOUT;
 299                 retries = 1;
 300                 break;
 301         case START_STOP:
 302                 timeout = START_STOP_TIMEOUT;
 303                 retries = NORMAL_RETRIES;
 304                 break;
 305         case MOVE_MEDIUM:
 306                 timeout = MOVE_MEDIUM_TIMEOUT;
 307                 retries = NORMAL_RETRIES;
 308                 break;
 309         case READ_ELEMENT_STATUS:
 310                 timeout = READ_ELEMENT_STATUS_TIMEOUT;
 311                 retries = NORMAL_RETRIES;
 312                 break;
 313         case READ_DEFECT_DATA:
 314                 timeout = READ_DEFECT_DATA_TIMEOUT;
 315                 retries = 1;
 316                 break;
 317         default:
 318                 timeout = IOCTL_NORMAL_TIMEOUT;
 319                 retries = NORMAL_RETRIES;
 320                 break;
 321         }
 322
 323         sreq = scsi_allocate_request(sdev, GFP_KERNEL);
 324         if (!sreq) {
 325                 result = -EINTR;
 326                 goto error;
 327         }
 328
 329         sreq->sr_data_direction = data_direction;
 330         scsi_wait_req(sreq, cmd, buf, needed, timeout, retries);
 331
 332         /*
 333          * If there was an error condition, pass the info back to the user.
 334          */
 335         result = sreq->sr_result;
 336         if (result) {
 337                 int sb_len = sizeof(sreq->sr_sense_buffer);
 338
 339                 sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len;
 340                 if (copy_to_user(cmd_in, sreq->sr_sense_buffer, sb_len))
 341                         result = -EFAULT;
 342         } else {
 343                 if (copy_to_user(cmd_in, buf, outlen))
 344                         result = -EFAULT;
 345         }
 346
 347         scsi_release_request(sreq);
 348 error:
 349         kfree(buf);
 350         return result;
 351 }
 352
 353 /*
 354  * The scsi_ioctl_get_pci() function places into arg the value
 355  * pci_dev::slot_name (8 characters) for the PCI device (if any).
 356  * Returns: 0 on success
 357  *          -ENXIO if there isn't a PCI device pointer
 358  *                 (could be because the SCSI driver hasn't been
 359  *                  updated yet, or because it isn't a SCSI
 360  *                  device)
 361  *          any copy_to_user() error on failure there
 362  */
 363 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 364 {
 365         struct device *dev = scsi_get_device(sdev->host);
 366
 367         if (!dev)
 368                 return -ENXIO;
 369         return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0;
 370 }
 371
 372
 373 /*
 374  * the scsi_ioctl() function differs from most ioctls in that it does
 375  * not take a major/minor number as the dev field.  Rather, it takes
 376  * a pointer to a scsi_devices[] element, a structure.
 377  */
 378 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 379 {
 380         char scsi_cmd[MAX_COMMAND_SIZE];
 381
 382         /* No idea how this happens.... */
 383         if (!sdev)
 384                 return -ENXIO;
 385
 386         /*
 387          * If we are in the middle of error recovery, don't let anyone
 388          * else try and use this device.  Also, if error recovery fails, it
 389          * may try and take the device offline, in which case all further
 390          * access to the device is prohibited.
 391          */
 392         if (!scsi_block_when_processing_errors(sdev))
 393                 return -ENODEV;
 394
 395         /* Check for deprecated ioctls ... all the ioctls which don't
 396          * follow the new unique numbering scheme are deprecated */
 397         switch (cmd) {
 398         case SCSI_IOCTL_SEND_COMMAND:
 399         case SCSI_IOCTL_TEST_UNIT_READY:
 400         case SCSI_IOCTL_BENCHMARK_COMMAND:
 401         case SCSI_IOCTL_SYNC:
 402         case SCSI_IOCTL_START_UNIT:
 403         case SCSI_IOCTL_STOP_UNIT:
 404                 printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
 405                 break;
 406         default:
 407                 break;
 408         }
 409
 410         switch (cmd) {
 411         case SCSI_IOCTL_GET_IDLUN:
 412                 if (verify_area(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 413                         return -EFAULT;
 414
 415                 __put_user((sdev->id & 0xff)
 416                          + ((sdev->lun & 0xff) << 8)
 417                          + ((sdev->channel & 0xff) << 16)
 418                          + ((sdev->host->host_no & 0xff) << 24),
 419                          &((struct scsi_idlun __user *)arg)->dev_id);
 420                 __put_user(sdev->host->unique_id,
 421                          &((struct scsi_idlun __user *)arg)->host_unique_id);
 422                 return 0;
 423         case SCSI_IOCTL_GET_BUS_NUMBER:
 424                 return put_user(sdev->host->host_no, (int __user *)arg);
 425         case SCSI_IOCTL_PROBE_HOST:
 426                 return ioctl_probe(sdev->host, arg);
 427         case SCSI_IOCTL_SEND_COMMAND:
 428                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 429                         return -EACCES;
 430                 return scsi_ioctl_send_command(sdev, arg);
 431         case SCSI_IOCTL_DOORLOCK:
 432                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 433         case SCSI_IOCTL_DOORUNLOCK:
 434                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 435         case SCSI_IOCTL_TEST_UNIT_READY:
 436                 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 437                                             NORMAL_RETRIES);
 438         case SCSI_IOCTL_START_UNIT:
 439                 scsi_cmd[0] = START_STOP;
 440                 scsi_cmd[1] = 0;
 441                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 442                 scsi_cmd[4] = 1;
 443                 return ioctl_internal_command(sdev, scsi_cmd,
 444                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 445         case SCSI_IOCTL_STOP_UNIT:
 446                 scsi_cmd[0] = START_STOP;
 447                 scsi_cmd[1] = 0;
 448                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 449                 scsi_cmd[4] = 0;
 450                 return ioctl_internal_command(sdev, scsi_cmd,
 451                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 452         case SCSI_IOCTL_GET_PCI:
 453                 return scsi_ioctl_get_pci(sdev, arg);
 454         default:
 455                 if (sdev->host->hostt->ioctl)
 456                         return sdev->host->hostt->ioctl(sdev, cmd, arg);
 457         }
 458         return -EINVAL;
 459 }