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_cmnd.h>
  19 #include <scsi/scsi_device.h>
  20 #include <scsi/scsi_eh.h>
  21 #include <scsi/scsi_host.h>
  22 #include <scsi/scsi_ioctl.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, NULL);
  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)
 114                                 break;
 115                 case UNIT_ATTENTION:
 116                         if (sdev->removable) {
 117                                 sdev->changed = 1;
 118                                 result = 0;     /* This is no longer considered an error */
 119                                 break;
 120                         }
 121                 default:        /* Fall through for non-removable media */
 122                         sdev_printk(KERN_INFO, sdev,
 123                                     "ioctl_internal_command return code = %x\n",
 124                                     result);
 125                         scsi_print_sense_hdr("   ", &sshdr);
 126                         break;
 127                 }
 128         }
 129
 130         SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
 131         return result;
 132 }
 133
 134 int scsi_set_medium_removal(struct scsi_device *sdev, char state)
 135 {
 136         char scsi_cmd[MAX_COMMAND_SIZE];
 137         int ret;
 138
 139         if (!sdev->removable || !sdev->lockable)
 140                return 0;
 141
 142         scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 143         scsi_cmd[1] = 0;
 144         scsi_cmd[2] = 0;
 145         scsi_cmd[3] = 0;
 146         scsi_cmd[4] = state;
 147         scsi_cmd[5] = 0;
 148
 149         ret = ioctl_internal_command(sdev, scsi_cmd,
 150                         IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
 151         if (ret == 0)
 152                 sdev->locked = (state == SCSI_REMOVAL_PREVENT);
 153         return ret;
 154 }
 155 EXPORT_SYMBOL(scsi_set_medium_removal);
 156
 157 /*
 158  * The scsi_ioctl_get_pci() function places into arg the value
 159  * pci_dev::slot_name (8 characters) for the PCI device (if any).
 160  * Returns: 0 on success
 161  *          -ENXIO if there isn't a PCI device pointer
 162  *                 (could be because the SCSI driver hasn't been
 163  *                  updated yet, or because it isn't a SCSI
 164  *                  device)
 165  *          any copy_to_user() error on failure there
 166  */
 167 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 168 {
 169         struct device *dev = scsi_get_device(sdev->host);
 170         const char *name;
 171
 172         if (!dev)
 173                 return -ENXIO;
 174
 175         name = dev_name(dev);
 176
 177         /* compatibility with old ioctl which only returned
 178          * 20 characters */
 179         return copy_to_user(arg, name, min(strlen(name), (size_t)20))
 180                 ? -EFAULT: 0;
 181 }
 182
 183
 184 /**
 185  * scsi_ioctl - Dispatch ioctl to scsi device
 186  * @sdev: scsi device receiving ioctl
 187  * @cmd: which ioctl is it
 188  * @arg: data associated with ioctl
 189  *
 190  * Description: The scsi_ioctl() function differs from most ioctls in that it
 191  * does not take a major/minor number as the dev field.  Rather, it takes
 192  * a pointer to a &struct scsi_device.
 193  */
 194 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 195 {
 196         char scsi_cmd[MAX_COMMAND_SIZE];
 197
 198         /* No idea how this happens.... */
 199         if (!sdev)
 200                 return -ENXIO;
 201
 202         /*
 203          * If we are in the middle of error recovery, don't let anyone
 204          * else try and use this device.  Also, if error recovery fails, it
 205          * may try and take the device offline, in which case all further
 206          * access to the device is prohibited.
 207          */
 208         if (!scsi_block_when_processing_errors(sdev))
 209                 return -ENODEV;
 210
 211         /* Check for deprecated ioctls ... all the ioctls which don't
 212          * follow the new unique numbering scheme are deprecated */
 213         switch (cmd) {
 214         case SCSI_IOCTL_SEND_COMMAND:
 215         case SCSI_IOCTL_TEST_UNIT_READY:
 216         case SCSI_IOCTL_BENCHMARK_COMMAND:
 217         case SCSI_IOCTL_SYNC:
 218         case SCSI_IOCTL_START_UNIT:
 219         case SCSI_IOCTL_STOP_UNIT:
 220                 printk(KERN_WARNING "program %s is using a deprecated SCSI "
 221                        "ioctl, please convert it to SG_IO\n", current->comm);
 222                 break;
 223         default:
 224                 break;
 225         }
 226
 227         switch (cmd) {
 228         case SCSI_IOCTL_GET_IDLUN:
 229                 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 230                         return -EFAULT;
 231
 232                 __put_user((sdev->id & 0xff)
 233                          + ((sdev->lun & 0xff) << 8)
 234                          + ((sdev->channel & 0xff) << 16)
 235                          + ((sdev->host->host_no & 0xff) << 24),
 236                          &((struct scsi_idlun __user *)arg)->dev_id);
 237                 __put_user(sdev->host->unique_id,
 238                          &((struct scsi_idlun __user *)arg)->host_unique_id);
 239                 return 0;
 240         case SCSI_IOCTL_GET_BUS_NUMBER:
 241                 return put_user(sdev->host->host_no, (int __user *)arg);
 242         case SCSI_IOCTL_PROBE_HOST:
 243                 return ioctl_probe(sdev->host, arg);
 244         case SCSI_IOCTL_SEND_COMMAND:
 245                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 246                         return -EACCES;
 247                 return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
 248         case SCSI_IOCTL_DOORLOCK:
 249                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 250         case SCSI_IOCTL_DOORUNLOCK:
 251                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 252         case SCSI_IOCTL_TEST_UNIT_READY:
 253                 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 254                                             NORMAL_RETRIES, NULL);
 255         case SCSI_IOCTL_START_UNIT:
 256                 scsi_cmd[0] = START_STOP;
 257                 scsi_cmd[1] = 0;
 258                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 259                 scsi_cmd[4] = 1;
 260                 return ioctl_internal_command(sdev, scsi_cmd,
 261                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 262         case SCSI_IOCTL_STOP_UNIT:
 263                 scsi_cmd[0] = START_STOP;
 264                 scsi_cmd[1] = 0;
 265                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 266                 scsi_cmd[4] = 0;
 267                 return ioctl_internal_command(sdev, scsi_cmd,
 268                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 269         case SCSI_IOCTL_GET_PCI:
 270                 return scsi_ioctl_get_pci(sdev, arg);
 271         default:
 272                 if (sdev->host->hostt->ioctl)
 273                         return sdev->host->hostt->ioctl(sdev, cmd, arg);
 274         }
 275         return -EINVAL;
 276 }
 277 EXPORT_SYMBOL(scsi_ioctl);
 278
 279 /**
 280  * scsi_nonblockable_ioctl() - Handle SG_SCSI_RESET
 281  * @sdev: scsi device receiving ioctl
 282  * @cmd: Must be SC_SCSI_RESET
 283  * @arg: pointer to int containing SG_SCSI_RESET_{DEVICE,BUS,HOST}
 284  * @ndelay: file mode O_NDELAY flag
 285  */
 286 int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
 287                             void __user *arg, int ndelay)
 288 {
 289         int val, result;
 290
 291         /* The first set of iocts may be executed even if we're doing
 292          * error processing, as long as the device was opened
 293          * non-blocking */
 294         if (ndelay) {
 295                 if (scsi_host_in_recovery(sdev->host))
 296                         return -ENODEV;
 297         } else if (!scsi_block_when_processing_errors(sdev))
 298                 return -ENODEV;
 299
 300         switch (cmd) {
 301         case SG_SCSI_RESET:
 302                 result = get_user(val, (int __user *)arg);
 303                 if (result)
 304                         return result;
 305                 if (val == SG_SCSI_RESET_NOTHING)
 306                         return 0;
 307                 switch (val) {
 308                 case SG_SCSI_RESET_DEVICE:
 309                         val = SCSI_TRY_RESET_DEVICE;
 310                         break;
 311                 case SG_SCSI_RESET_BUS:
 312                         val = SCSI_TRY_RESET_BUS;
 313                         break;
 314                 case SG_SCSI_RESET_HOST:
 315                         val = SCSI_TRY_RESET_HOST;
 316                         break;
 317                 default:
 318                         return -EINVAL;
 319                 }
 320                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 321                         return -EACCES;
 322                 return (scsi_reset_provider(sdev, val) ==
 323                         SUCCESS) ? 0 : -EIO;
 324         }
 325         return -ENODEV;
 326 }
 327 EXPORT_SYMBOL(scsi_nonblockable_ioctl);