block/scsi_ioctl.c

   1 /*
   2  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public Licens
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  17  *
  18  */
  19 #include <linux/kernel.h>
  20 #include <linux/errno.h>
  21 #include <linux/string.h>
  22 #include <linux/module.h>
  23 #include <linux/blkdev.h>
  24 #include <linux/capability.h>
  25 #include <linux/completion.h>
  26 #include <linux/cdrom.h>
  27 #include <linux/slab.h>
  28 #include <linux/times.h>
  29 #include <asm/uaccess.h>
  30
  31 #include <scsi/scsi.h>
  32 #include <scsi/scsi_ioctl.h>
  33 #include <scsi/scsi_cmnd.h>
  34
  35 /* Command group 3 is reserved and should never be used.  */
  36 const unsigned char scsi_command_size_tbl[8] =
  37 {
  38         6, 10, 10, 12,
  39         16, 12, 10, 10
  40 };
  41 EXPORT_SYMBOL(scsi_command_size_tbl);
  42
  43 #include <scsi/sg.h>
  44
  45 static int sg_get_version(int __user *p)
  46 {
  47         static const int sg_version_num = 30527;
  48         return put_user(sg_version_num, p);
  49 }
  50
  51 static int scsi_get_idlun(struct request_queue *q, int __user *p)
  52 {
  53         return put_user(0, p);
  54 }
  55
  56 static int scsi_get_bus(struct request_queue *q, int __user *p)
  57 {
  58         return put_user(0, p);
  59 }
  60
  61 static int sg_get_timeout(struct request_queue *q)
  62 {
  63         return q->sg_timeout / (HZ / USER_HZ);
  64 }
  65
  66 static int sg_set_timeout(struct request_queue *q, int __user *p)
  67 {
  68         int timeout, err = get_user(timeout, p);
  69
  70         if (!err)
  71                 q->sg_timeout = timeout * (HZ / USER_HZ);
  72
  73         return err;
  74 }
  75
  76 static int sg_get_reserved_size(struct request_queue *q, int __user *p)
  77 {
  78         unsigned val = min(q->sg_reserved_size, q->max_sectors << 9);
  79
  80         return put_user(val, p);
  81 }
  82
  83 static int sg_set_reserved_size(struct request_queue *q, int __user *p)
  84 {
  85         int size, err = get_user(size, p);
  86
  87         if (err)
  88                 return err;
  89
  90         if (size < 0)
  91                 return -EINVAL;
  92         if (size > (q->max_sectors << 9))
  93                 size = q->max_sectors << 9;
  94
  95         q->sg_reserved_size = size;
  96         return 0;
  97 }
  98
  99 /*
 100  * will always return that we are ATAPI even for a real SCSI drive, I'm not
 101  * so sure this is worth doing anything about (why would you care??)
 102  */
 103 static int sg_emulated_host(struct request_queue *q, int __user *p)
 104 {
 105         return put_user(1, p);
 106 }
 107
 108 static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
 109                              struct sg_io_hdr *hdr, struct file *file)
 110 {
 111         if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
 112                 return -EFAULT;
 113         if (blk_verify_command(file, rq->cmd))
 114                 return -EPERM;
 115
 116         /*
 117          * fill in request structure
 118          */
 119         rq->cmd_len = hdr->cmd_len;
 120         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 121
 122         rq->timeout = msecs_to_jiffies(hdr->timeout);
 123         if (!rq->timeout)
 124                 rq->timeout = q->sg_timeout;
 125         if (!rq->timeout)
 126                 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
 127
 128         return 0;
 129 }
 130
 131 /*
 132  * unmap a request that was previously mapped to this sg_io_hdr. handles
 133  * both sg and non-sg sg_io_hdr.
 134  */
 135 static int blk_unmap_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr)
 136 {
 137         blk_rq_unmap_user(rq->bio);
 138         blk_put_request(rq);
 139         return 0;
 140 }
 141
 142 static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
 143                                  struct bio *bio)
 144 {
 145         int r, ret = 0;
 146
 147         /*
 148          * fill in all the output members
 149          */
 150         hdr->status = rq->errors & 0xff;
 151         hdr->masked_status = status_byte(rq->errors);
 152         hdr->msg_status = msg_byte(rq->errors);
 153         hdr->host_status = host_byte(rq->errors);
 154         hdr->driver_status = driver_byte(rq->errors);
 155         hdr->info = 0;
 156         if (hdr->masked_status || hdr->host_status || hdr->driver_status)
 157                 hdr->info |= SG_INFO_CHECK;
 158         hdr->resid = rq->data_len;
 159         hdr->sb_len_wr = 0;
 160
 161         if (rq->sense_len && hdr->sbp) {
 162                 int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
 163
 164                 if (!copy_to_user(hdr->sbp, rq->sense, len))
 165                         hdr->sb_len_wr = len;
 166                 else
 167                         ret = -EFAULT;
 168         }
 169
 170         rq->bio = bio;
 171         r = blk_unmap_sghdr_rq(rq, hdr);
 172         if (ret)
 173                 r = ret;
 174
 175         return r;
 176 }
 177
 178 static int sg_io(struct file *file, struct request_queue *q,
 179                 struct gendisk *bd_disk, struct sg_io_hdr *hdr)
 180 {
 181         unsigned long start_time;
 182         int writing = 0, ret = 0;
 183         struct request *rq;
 184         char sense[SCSI_SENSE_BUFFERSIZE];
 185         struct bio *bio;
 186
 187         if (hdr->interface_id != 'S')
 188                 return -EINVAL;
 189         if (hdr->cmd_len > BLK_MAX_CDB)
 190                 return -EINVAL;
 191
 192         if (hdr->dxfer_len > (q->max_hw_sectors << 9))
 193                 return -EIO;
 194
 195         if (hdr->dxfer_len)
 196                 switch (hdr->dxfer_direction) {
 197                 default:
 198                         return -EINVAL;
 199                 case SG_DXFER_TO_DEV:
 200                         writing = 1;
 201                         break;
 202                 case SG_DXFER_TO_FROM_DEV:
 203                 case SG_DXFER_FROM_DEV:
 204                         break;
 205                 }
 206
 207         rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
 208         if (!rq)
 209                 return -ENOMEM;
 210
 211         if (blk_fill_sghdr_rq(q, rq, hdr, file)) {
 212                 blk_put_request(rq);
 213                 return -EFAULT;
 214         }
 215
 216         if (hdr->iovec_count) {
 217                 const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
 218                 struct sg_iovec *iov;
 219
 220                 iov = kmalloc(size, GFP_KERNEL);
 221                 if (!iov) {
 222                         ret = -ENOMEM;
 223                         goto out;
 224                 }
 225
 226                 if (copy_from_user(iov, hdr->dxferp, size)) {
 227                         kfree(iov);
 228                         ret = -EFAULT;
 229                         goto out;
 230                 }
 231
 232                 ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count,
 233                                           hdr->dxfer_len);
 234                 kfree(iov);
 235         } else if (hdr->dxfer_len)
 236                 ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
 237
 238         if (ret)
 239                 goto out;
 240
 241         bio = rq->bio;
 242         memset(sense, 0, sizeof(sense));
 243         rq->sense = sense;
 244         rq->sense_len = 0;
 245         rq->retries = 0;
 246
 247         start_time = jiffies;
 248
 249         /* ignore return value. All information is passed back to caller
 250          * (if he doesn't check that is his problem).
 251          * N.B. a non-zero SCSI status is _not_ necessarily an error.
 252          */
 253         blk_execute_rq(q, bd_disk, rq, 0);
 254
 255         hdr->duration = jiffies_to_msecs(jiffies - start_time);
 256
 257         return blk_complete_sghdr_rq(rq, hdr, bio);
 258 out:
 259         blk_put_request(rq);
 260         return ret;
 261 }
 262
 263 /**
 264  * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
 265  * @file:       file this ioctl operates on (optional)
 266  * @q:          request queue to send scsi commands down
 267  * @disk:       gendisk to operate on (option)
 268  * @sic:        userspace structure describing the command to perform
 269  *
 270  * Send down the scsi command described by @sic to the device below
 271  * the request queue @q.  If @file is non-NULL it's used to perform
 272  * fine-grained permission checks that allow users to send down
 273  * non-destructive SCSI commands.  If the caller has a struct gendisk
 274  * available it should be passed in as @disk to allow the low level
 275  * driver to use the information contained in it.  A non-NULL @disk
 276  * is only allowed if the caller knows that the low level driver doesn't
 277  * need it (e.g. in the scsi subsystem).
 278  *
 279  * Notes:
 280  *   -  This interface is deprecated - users should use the SG_IO
 281  *      interface instead, as this is a more flexible approach to
 282  *      performing SCSI commands on a device.
 283  *   -  The SCSI command length is determined by examining the 1st byte
 284  *      of the given command. There is no way to override this.
 285  *   -  Data transfers are limited to PAGE_SIZE
 286  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 287  *      accommodate the sense buffer when an error occurs.
 288  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 289  *      old code will not be surprised.
 290  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 291  *      a negative return and the Unix error code in 'errno'.
 292  *      If the SCSI command succeeds then 0 is returned.
 293  *      Positive numbers returned are the compacted SCSI error codes (4
 294  *      bytes in one int) where the lowest byte is the SCSI status.
 295  */
 296 #define OMAX_SB_LEN 16          /* For backward compatibility */
 297 int sg_scsi_ioctl(struct file *file, struct request_queue *q,
 298                   struct gendisk *disk, struct scsi_ioctl_command __user *sic)
 299 {
 300         struct request *rq;
 301         int err;
 302         unsigned int in_len, out_len, bytes, opcode, cmdlen;
 303         char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];
 304
 305         if (!sic)
 306                 return -EINVAL;
 307
 308         /*
 309          * get in an out lengths, verify they don't exceed a page worth of data
 310          */
 311         if (get_user(in_len, &sic->inlen))
 312                 return -EFAULT;
 313         if (get_user(out_len, &sic->outlen))
 314                 return -EFAULT;
 315         if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
 316                 return -EINVAL;
 317         if (get_user(opcode, sic->data))
 318                 return -EFAULT;
 319
 320         bytes = max(in_len, out_len);
 321         if (bytes) {
 322                 buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
 323                 if (!buffer)
 324                         return -ENOMEM;
 325
 326         }
 327
 328         rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
 329
 330         cmdlen = COMMAND_SIZE(opcode);
 331
 332         /*
 333          * get command and data to send to device, if any
 334          */
 335         err = -EFAULT;
 336         rq->cmd_len = cmdlen;
 337         if (copy_from_user(rq->cmd, sic->data, cmdlen))
 338                 goto error;
 339
 340         if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
 341                 goto error;
 342
 343         err = blk_verify_command(file, rq->cmd);
 344         if (err)
 345                 goto error;
 346
 347         /* default.  possible overriden later */
 348         rq->retries = 5;
 349
 350         switch (opcode) {
 351         case SEND_DIAGNOSTIC:
 352         case FORMAT_UNIT:
 353                 rq->timeout = FORMAT_UNIT_TIMEOUT;
 354                 rq->retries = 1;
 355                 break;
 356         case START_STOP:
 357                 rq->timeout = START_STOP_TIMEOUT;
 358                 break;
 359         case MOVE_MEDIUM:
 360                 rq->timeout = MOVE_MEDIUM_TIMEOUT;
 361                 break;
 362         case READ_ELEMENT_STATUS:
 363                 rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
 364                 break;
 365         case READ_DEFECT_DATA:
 366                 rq->timeout = READ_DEFECT_DATA_TIMEOUT;
 367                 rq->retries = 1;
 368                 break;
 369         default:
 370                 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
 371                 break;
 372         }
 373
 374         if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_WAIT)) {
 375                 err = DRIVER_ERROR << 24;
 376                 goto out;
 377         }
 378
 379         memset(sense, 0, sizeof(sense));
 380         rq->sense = sense;
 381         rq->sense_len = 0;
 382         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 383
 384         blk_execute_rq(q, disk, rq, 0);
 385
 386 out:
 387         err = rq->errors & 0xff;        /* only 8 bit SCSI status */
 388         if (err) {
 389                 if (rq->sense_len && rq->sense) {
 390                         bytes = (OMAX_SB_LEN > rq->sense_len) ?
 391                                 rq->sense_len : OMAX_SB_LEN;
 392                         if (copy_to_user(sic->data, rq->sense, bytes))
 393                                 err = -EFAULT;
 394                 }
 395         } else {
 396                 if (copy_to_user(sic->data, buffer, out_len))
 397                         err = -EFAULT;
 398         }
 399
 400 error:
 401         kfree(buffer);
 402         blk_put_request(rq);
 403         return err;
 404 }
 405 EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
 406
 407 /* Send basic block requests */
 408 static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
 409                               int cmd, int data)
 410 {
 411         struct request *rq;
 412         int err;
 413
 414         rq = blk_get_request(q, WRITE, __GFP_WAIT);
 415         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 416         rq->data = NULL;
 417         rq->data_len = 0;
 418         rq->extra_len = 0;
 419         rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
 420         rq->cmd[0] = cmd;
 421         rq->cmd[4] = data;
 422         rq->cmd_len = 6;
 423         err = blk_execute_rq(q, bd_disk, rq, 0);
 424         blk_put_request(rq);
 425
 426         return err;
 427 }
 428
 429 static inline int blk_send_start_stop(struct request_queue *q,
 430                                       struct gendisk *bd_disk, int data)
 431 {
 432         return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
 433 }
 434
 435 int scsi_cmd_ioctl(struct file *file, struct request_queue *q,
 436                    struct gendisk *bd_disk, unsigned int cmd, void __user *arg)
 437 {
 438         int err;
 439
 440         if (!q || blk_get_queue(q))
 441                 return -ENXIO;
 442
 443         switch (cmd) {
 444                 /*
 445                  * new sgv3 interface
 446                  */
 447                 case SG_GET_VERSION_NUM:
 448                         err = sg_get_version(arg);
 449                         break;
 450                 case SCSI_IOCTL_GET_IDLUN:
 451                         err = scsi_get_idlun(q, arg);
 452                         break;
 453                 case SCSI_IOCTL_GET_BUS_NUMBER:
 454                         err = scsi_get_bus(q, arg);
 455                         break;
 456                 case SG_SET_TIMEOUT:
 457                         err = sg_set_timeout(q, arg);
 458                         break;
 459                 case SG_GET_TIMEOUT:
 460                         err = sg_get_timeout(q);
 461                         break;
 462                 case SG_GET_RESERVED_SIZE:
 463                         err = sg_get_reserved_size(q, arg);
 464                         break;
 465                 case SG_SET_RESERVED_SIZE:
 466                         err = sg_set_reserved_size(q, arg);
 467                         break;
 468                 case SG_EMULATED_HOST:
 469                         err = sg_emulated_host(q, arg);
 470                         break;
 471                 case SG_IO: {
 472                         struct sg_io_hdr hdr;
 473
 474                         err = -EFAULT;
 475                         if (copy_from_user(&hdr, arg, sizeof(hdr)))
 476                                 break;
 477                         err = sg_io(file, q, bd_disk, &hdr);
 478                         if (err == -EFAULT)
 479                                 break;
 480
 481                         if (copy_to_user(arg, &hdr, sizeof(hdr)))
 482                                 err = -EFAULT;
 483                         break;
 484                 }
 485                 case CDROM_SEND_PACKET: {
 486                         struct cdrom_generic_command cgc;
 487                         struct sg_io_hdr hdr;
 488
 489                         err = -EFAULT;
 490                         if (copy_from_user(&cgc, arg, sizeof(cgc)))
 491                                 break;
 492                         cgc.timeout = clock_t_to_jiffies(cgc.timeout);
 493                         memset(&hdr, 0, sizeof(hdr));
 494                         hdr.interface_id = 'S';
 495                         hdr.cmd_len = sizeof(cgc.cmd);
 496                         hdr.dxfer_len = cgc.buflen;
 497                         err = 0;
 498                         switch (cgc.data_direction) {
 499                                 case CGC_DATA_UNKNOWN:
 500                                         hdr.dxfer_direction = SG_DXFER_UNKNOWN;
 501                                         break;
 502                                 case CGC_DATA_WRITE:
 503                                         hdr.dxfer_direction = SG_DXFER_TO_DEV;
 504                                         break;
 505                                 case CGC_DATA_READ:
 506                                         hdr.dxfer_direction = SG_DXFER_FROM_DEV;
 507                                         break;
 508                                 case CGC_DATA_NONE:
 509                                         hdr.dxfer_direction = SG_DXFER_NONE;
 510                                         break;
 511                                 default:
 512                                         err = -EINVAL;
 513                         }
 514                         if (err)
 515                                 break;
 516
 517                         hdr.dxferp = cgc.buffer;
 518                         hdr.sbp = cgc.sense;
 519                         if (hdr.sbp)
 520                                 hdr.mx_sb_len = sizeof(struct request_sense);
 521                         hdr.timeout = jiffies_to_msecs(cgc.timeout);
 522                         hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
 523                         hdr.cmd_len = sizeof(cgc.cmd);
 524
 525                         err = sg_io(file, q, bd_disk, &hdr);
 526                         if (err == -EFAULT)
 527                                 break;
 528
 529                         if (hdr.status)
 530                                 err = -EIO;
 531
 532                         cgc.stat = err;
 533                         cgc.buflen = hdr.resid;
 534                         if (copy_to_user(arg, &cgc, sizeof(cgc)))
 535                                 err = -EFAULT;
 536
 537                         break;
 538                 }
 539
 540                 /*
 541                  * old junk scsi send command ioctl
 542                  */
 543                 case SCSI_IOCTL_SEND_COMMAND:
 544                         printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
 545                         err = -EINVAL;
 546                         if (!arg)
 547                                 break;
 548
 549                         err = sg_scsi_ioctl(file, q, bd_disk, arg);
 550                         break;
 551                 case CDROMCLOSETRAY:
 552                         err = blk_send_start_stop(q, bd_disk, 0x03);
 553                         break;
 554                 case CDROMEJECT:
 555                         err = blk_send_start_stop(q, bd_disk, 0x02);
 556                         break;
 557                 default:
 558                         err = -ENOTTY;
 559         }
 560
 561         blk_put_queue(q);
 562         return err;
 563 }
 564
 565 EXPORT_SYMBOL(scsi_cmd_ioctl);