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 <linux/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, sdev_printk(KERN_INFO, sdev,
  95                                       "Trying ioctl with scsi command %d\n", *cmd));
  96
  97         result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
  98                                   &sshdr, timeout, retries, NULL);
  99
 100         SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
 101                                       "Ioctl returned  0x%x\n", result));
 102
 103         if ((driver_byte(result) & DRIVER_SENSE) &&
 104             (scsi_sense_valid(&sshdr))) {
 105                 switch (sshdr.sense_key) {
 106                 case ILLEGAL_REQUEST:
 107                         if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
 108                                 sdev->lockable = 0;
 109                         else
 110                                 sdev_printk(KERN_INFO, sdev,
 111                                             "ioctl_internal_command: "
 112                                             "ILLEGAL REQUEST "
 113                                             "asc=0x%x ascq=0x%x\n",
 114                                             sshdr.asc, sshdr.ascq);
 115                         break;
 116                 case NOT_READY: /* This happens if there is no disc in drive */
 117                         if (sdev->removable)
 118                                 break;
 119                 case UNIT_ATTENTION:
 120                         if (sdev->removable) {
 121                                 sdev->changed = 1;
 122                                 result = 0;     /* This is no longer considered an error */
 123                                 break;
 124                         }
 125                 default:        /* Fall through for non-removable media */
 126                         sdev_printk(KERN_INFO, sdev,
 127                                     "ioctl_internal_command return code = %x\n",
 128                                     result);
 129                         scsi_print_sense_hdr(sdev, NULL, &sshdr);
 130                         break;
 131                 }
 132         }
 133
 134         SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
 135                                       "IOCTL Releasing command\n"));
 136         return result;
 137 }
 138
 139 int scsi_set_medium_removal(struct scsi_device *sdev, char state)
 140 {
 141         char scsi_cmd[MAX_COMMAND_SIZE];
 142         int ret;
 143
 144         if (!sdev->removable || !sdev->lockable)
 145                return 0;
 146
 147         scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 148         scsi_cmd[1] = 0;
 149         scsi_cmd[2] = 0;
 150         scsi_cmd[3] = 0;
 151         scsi_cmd[4] = state;
 152         scsi_cmd[5] = 0;
 153
 154         ret = ioctl_internal_command(sdev, scsi_cmd,
 155                         IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
 156         if (ret == 0)
 157                 sdev->locked = (state == SCSI_REMOVAL_PREVENT);
 158         return ret;
 159 }
 160 EXPORT_SYMBOL(scsi_set_medium_removal);
 161
 162 /*
 163  * The scsi_ioctl_get_pci() function places into arg the value
 164  * pci_dev::slot_name (8 characters) for the PCI device (if any).
 165  * Returns: 0 on success
 166  *          -ENXIO if there isn't a PCI device pointer
 167  *                 (could be because the SCSI driver hasn't been
 168  *                  updated yet, or because it isn't a SCSI
 169  *                  device)
 170  *          any copy_to_user() error on failure there
 171  */
 172 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 173 {
 174         struct device *dev = scsi_get_device(sdev->host);
 175         const char *name;
 176
 177         if (!dev)
 178                 return -ENXIO;
 179
 180         name = dev_name(dev);
 181
 182         /* compatibility with old ioctl which only returned
 183          * 20 characters */
 184         return copy_to_user(arg, name, min(strlen(name), (size_t)20))
 185                 ? -EFAULT: 0;
 186 }
 187
 188
 189 /**
 190  * scsi_ioctl - Dispatch ioctl to scsi device
 191  * @sdev: scsi device receiving ioctl
 192  * @cmd: which ioctl is it
 193  * @arg: data associated with ioctl
 194  *
 195  * Description: The scsi_ioctl() function differs from most ioctls in that it
 196  * does not take a major/minor number as the dev field.  Rather, it takes
 197  * a pointer to a &struct scsi_device.
 198  */
 199 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 200 {
 201         char scsi_cmd[MAX_COMMAND_SIZE];
 202
 203         /* Check for deprecated ioctls ... all the ioctls which don't
 204          * follow the new unique numbering scheme are deprecated */
 205         switch (cmd) {
 206         case SCSI_IOCTL_SEND_COMMAND:
 207         case SCSI_IOCTL_TEST_UNIT_READY:
 208         case SCSI_IOCTL_BENCHMARK_COMMAND:
 209         case SCSI_IOCTL_SYNC:
 210         case SCSI_IOCTL_START_UNIT:
 211         case SCSI_IOCTL_STOP_UNIT:
 212                 printk(KERN_WARNING "program %s is using a deprecated SCSI "
 213                        "ioctl, please convert it to SG_IO\n", current->comm);
 214                 break;
 215         default:
 216                 break;
 217         }
 218
 219         switch (cmd) {
 220         case SCSI_IOCTL_GET_IDLUN:
 221                 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 222                         return -EFAULT;
 223
 224                 __put_user((sdev->id & 0xff)
 225                          + ((sdev->lun & 0xff) << 8)
 226                          + ((sdev->channel & 0xff) << 16)
 227                          + ((sdev->host->host_no & 0xff) << 24),
 228                          &((struct scsi_idlun __user *)arg)->dev_id);
 229                 __put_user(sdev->host->unique_id,
 230                          &((struct scsi_idlun __user *)arg)->host_unique_id);
 231                 return 0;
 232         case SCSI_IOCTL_GET_BUS_NUMBER:
 233                 return put_user(sdev->host->host_no, (int __user *)arg);
 234         case SCSI_IOCTL_PROBE_HOST:
 235                 return ioctl_probe(sdev->host, arg);
 236         case SCSI_IOCTL_SEND_COMMAND:
 237                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 238                         return -EACCES;
 239                 return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
 240         case SCSI_IOCTL_DOORLOCK:
 241                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 242         case SCSI_IOCTL_DOORUNLOCK:
 243                 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 244         case SCSI_IOCTL_TEST_UNIT_READY:
 245                 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 246                                             NORMAL_RETRIES, NULL);
 247         case SCSI_IOCTL_START_UNIT:
 248                 scsi_cmd[0] = START_STOP;
 249                 scsi_cmd[1] = 0;
 250                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 251                 scsi_cmd[4] = 1;
 252                 return ioctl_internal_command(sdev, scsi_cmd,
 253                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 254         case SCSI_IOCTL_STOP_UNIT:
 255                 scsi_cmd[0] = START_STOP;
 256                 scsi_cmd[1] = 0;
 257                 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 258                 scsi_cmd[4] = 0;
 259                 return ioctl_internal_command(sdev, scsi_cmd,
 260                                      START_STOP_TIMEOUT, NORMAL_RETRIES);
 261         case SCSI_IOCTL_GET_PCI:
 262                 return scsi_ioctl_get_pci(sdev, arg);
 263         case SG_SCSI_RESET:
 264                 return scsi_ioctl_reset(sdev, arg);
 265         default:
 266                 if (sdev->host->hostt->ioctl)
 267                         return sdev->host->hostt->ioctl(sdev, cmd, arg);
 268         }
 269         return -EINVAL;
 270 }
 271 EXPORT_SYMBOL(scsi_ioctl);
 272
 273 /*
 274  * We can process a reset even when a device isn't fully operable.
 275  */
 276 int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
 277                 bool ndelay)
 278 {
 279         if (cmd == SG_SCSI_RESET && ndelay) {
 280                 if (scsi_host_in_recovery(sdev->host))
 281                         return -EAGAIN;
 282         } else {
 283                 if (!scsi_block_when_processing_errors(sdev))
 284                         return -ENODEV;
 285         }
 286
 287         return 0;
 288 }
 289 EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);