LXR linux/drivers/scsi/scsi

   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 */
  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, 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                        /* FALLTHROUGH */
 120                case UNIT_ATTENTION:
 121                        if (sdev->removable) {
 122                                sdev->changed = 1;
 123                                result = 0;     /* This is no longer considered an error */
 124                                break;
 125                        }
 126                        /* FALLTHROUGH -- for non-removable media */
 127                default:
 128                        sdev_printk(KERN_INFO, sdev,
 129                                    "ioctl_internal_command return code = %x\n",
 130                                    result);
 131                        scsi_print_sense_hdr(sdev, NULL, &sshdr);
 132                        break;
 133                }
 134        }
 135
 136        SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
 137                                      "IOCTL Releasing command\n"));
 138        return result;
 139}
 140
 141int scsi_set_medium_removal(struct scsi_device *sdev, char state)
 142{
 143        char scsi_cmd[MAX_COMMAND_SIZE];
 144        int ret;
 145
 146        if (!sdev->removable || !sdev->lockable)
 147               return 0;
 148
 149        scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
 150        scsi_cmd[1] = 0;
 151        scsi_cmd[2] = 0;
 152        scsi_cmd[3] = 0;
 153        scsi_cmd[4] = state;
 154        scsi_cmd[5] = 0;
 155
 156        ret = ioctl_internal_command(sdev, scsi_cmd,
 157                        IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
 158        if (ret == 0)
 159                sdev->locked = (state == SCSI_REMOVAL_PREVENT);
 160        return ret;
 161}
 162EXPORT_SYMBOL(scsi_set_medium_removal);
 163
 164/*
 165 * The scsi_ioctl_get_pci() function places into arg the value
 166 * pci_dev::slot_name (8 characters) for the PCI device (if any).
 167 * Returns: 0 on success
 168 *          -ENXIO if there isn't a PCI device pointer
 169 *                 (could be because the SCSI driver hasn't been
 170 *                  updated yet, or because it isn't a SCSI
 171 *                  device)
 172 *          any copy_to_user() error on failure there
 173 */
 174static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 175{
 176        struct device *dev = scsi_get_device(sdev->host);
 177        const char *name;
 178
 179        if (!dev)
 180                return -ENXIO;
 181
 182        name = dev_name(dev);
 183
 184        /* compatibility with old ioctl which only returned
 185         * 20 characters */
 186        return copy_to_user(arg, name, min(strlen(name), (size_t)20))
 187                ? -EFAULT: 0;
 188}
 189
 190
 191/**
 192 * scsi_ioctl - Dispatch ioctl to scsi device
 193 * @sdev: scsi device receiving ioctl
 194 * @cmd: which ioctl is it
 195 * @arg: data associated with ioctl
 196 *
 197 * Description: The scsi_ioctl() function differs from most ioctls in that it
 198 * does not take a major/minor number as the dev field.  Rather, it takes
 199 * a pointer to a &struct scsi_device.
 200 */
 201int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 202{
 203        char scsi_cmd[MAX_COMMAND_SIZE];
 204        struct scsi_sense_hdr sense_hdr;
 205
 206        /* Check for deprecated ioctls ... all the ioctls which don't
 207         * follow the new unique numbering scheme are deprecated */
 208        switch (cmd) {
 209        case SCSI_IOCTL_SEND_COMMAND:
 210        case SCSI_IOCTL_TEST_UNIT_READY:
 211        case SCSI_IOCTL_BENCHMARK_COMMAND:
 212        case SCSI_IOCTL_SYNC:
 213        case SCSI_IOCTL_START_UNIT:
 214        case SCSI_IOCTL_STOP_UNIT:
 215                printk(KERN_WARNING "program %s is using a deprecated SCSI "
 216                       "ioctl, please convert it to SG_IO\n", current->comm);
 217                break;
 218        default:
 219                break;
 220        }
 221
 222        switch (cmd) {
 223        case SCSI_IOCTL_GET_IDLUN:
 224                if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 225                        return -EFAULT;
 226
 227                __put_user((sdev->id & 0xff)
 228                         + ((sdev->lun & 0xff) << 8)
 229                         + ((sdev->channel & 0xff) << 16)
 230                         + ((sdev->host->host_no & 0xff) << 24),
 231                         &((struct scsi_idlun __user *)arg)->dev_id);
 232                __put_user(sdev->host->unique_id,
 233                         &((struct scsi_idlun __user *)arg)->host_unique_id);
 234                return 0;
 235        case SCSI_IOCTL_GET_BUS_NUMBER:
 236                return put_user(sdev->host->host_no, (int __user *)arg);
 237        case SCSI_IOCTL_PROBE_HOST:
 238                return ioctl_probe(sdev->host, arg);
 239        case SCSI_IOCTL_SEND_COMMAND:
 240                if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 241                        return -EACCES;
 242                return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
 243        case SCSI_IOCTL_DOORLOCK:
 244                return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 245        case SCSI_IOCTL_DOORUNLOCK:
 246                return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 247        case SCSI_IOCTL_TEST_UNIT_READY:
 248                return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 249                                            NORMAL_RETRIES, &sense_hdr);
 250        case SCSI_IOCTL_START_UNIT:
 251                scsi_cmd[0] = START_STOP;
 252                scsi_cmd[1] = 0;
 253                scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 254                scsi_cmd[4] = 1;
 255                return ioctl_internal_command(sdev, scsi_cmd,
 256                                     START_STOP_TIMEOUT, NORMAL_RETRIES);
 257        case SCSI_IOCTL_STOP_UNIT:
 258                scsi_cmd[0] = START_STOP;
 259                scsi_cmd[1] = 0;
 260                scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 261                scsi_cmd[4] = 0;
 262                return ioctl_internal_command(sdev, scsi_cmd,
 263                                     START_STOP_TIMEOUT, NORMAL_RETRIES);
 264        case SCSI_IOCTL_GET_PCI:
 265                return scsi_ioctl_get_pci(sdev, arg);
 266        case SG_SCSI_RESET:
 267                return scsi_ioctl_reset(sdev, arg);
 268        default:
 269                if (sdev->host->hostt->ioctl)
 270                        return sdev->host->hostt->ioctl(sdev, cmd, arg);
 271        }
 272        return -EINVAL;
 273}
 274EXPORT_SYMBOL(scsi_ioctl);
 275
 276/*
 277 * We can process a reset even when a device isn't fully operable.
 278 */
 279int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
 280                bool ndelay)
 281{
 282        if (cmd == SG_SCSI_RESET && ndelay) {
 283                if (scsi_host_in_recovery(sdev->host))
 284                        return -EAGAIN;
 285        } else {
 286                if (!scsi_block_when_processing_errors(sdev))
 287                        return -ENODEV;
 288        }
 289
 290        return 0;
 291}
 292EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);
 293