linux/drivers/scsi/scsi_ioctl.c
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   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 */
  41static 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
  88static 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
 134int 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}
 155EXPORT_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 */
 167static 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 */
 194int 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}
 277EXPORT_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 */
 286int 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_TARGET:
 312                        val = SCSI_TRY_RESET_TARGET;
 313                        break;
 314                case SG_SCSI_RESET_BUS:
 315                        val = SCSI_TRY_RESET_BUS;
 316                        break;
 317                case SG_SCSI_RESET_HOST:
 318                        val = SCSI_TRY_RESET_HOST;
 319                        break;
 320                default:
 321                        return -EINVAL;
 322                }
 323                if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 324                        return -EACCES;
 325                return (scsi_reset_provider(sdev, val) ==
 326                        SUCCESS) ? 0 : -EIO;
 327        }
 328        return -ENODEV;
 329}
 330EXPORT_SYMBOL(scsi_nonblockable_ioctl);
 331
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