/*
   * Changes:
   * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
   * - get rid of some verify_areas and use __copy*user and __get/put_user
   *   for the ones that remain
   */
  #include <linux/module.h>
  #include <linux/blkdev.h>
  #include <linux/interrupt.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/sched.h>
  #include <linux/mm.h>
  #include <linux/string.h>
  #include <asm/uaccess.h>
  
  #include <scsi/scsi.h>
  #include <scsi/scsi_cmnd.h>
  #include <scsi/scsi_device.h>
  #include <scsi/scsi_eh.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_ioctl.h>
  #include <scsi/sg.h>
  #include <scsi/scsi_dbg.h>
  
  #include "scsi_logging.h"
  
  #define NORMAL_RETRIES			5
  #define IOCTL_NORMAL_TIMEOUT			(10 * HZ)
  
  #define MAX_BUF PAGE_SIZE
  
  /**
   * ioctl_probe  --  return host identification
   * @host:	host to identify
   * @buffer:	userspace buffer for identification
   *
   * Return an identifying string at @buffer, if @buffer is non-NULL, filling
   * to the length stored at * (int *) @buffer.
   */
  static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
  {
  	unsigned int len, slen;
  	const char *string;
  
  	if (buffer) {
  		if (get_user(len, (unsigned int __user *) buffer))
  			return -EFAULT;
  
  		if (host->hostt->info)
  			string = host->hostt->info(host);
  		else
  			string = host->hostt->name;
  		if (string) {
  			slen = strlen(string);
  			if (len > slen)
  				len = slen + 1;
  			if (copy_to_user(buffer, string, len))
  				return -EFAULT;
  		}
  	}
  	return 1;
  }
  
  /*
  
   * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
   * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES  variables are used.  
   * 
   * dev is the SCSI device struct ptr, *(int *) arg is the length of the
   * input data, if any, not including the command string & counts, 
   * *((int *)arg + 1) is the output buffer size in bytes.
   * 
   * *(char *) ((int *) arg)[2] the actual command byte.   
   * 
   * Note that if more than MAX_BUF bytes are requested to be transferred,
   * the ioctl will fail with error EINVAL.
   * 
   * This size *does not* include the initial lengths that were passed.
   * 
   * The SCSI command is read from the memory location immediately after the
   * length words, and the input data is right after the command.  The SCSI
   * routines know the command size based on the opcode decode.  
   * 
   * The output area is then filled in starting from the command byte. 
   */
  
  static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
  				  int timeout, int retries)
  {
  	int result;
  	struct scsi_sense_hdr sshdr;
  
  	SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d
  ", *cmd));
  
  	result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
  				  &sshdr, timeout, retries, NULL);
  
  	SCSI_LOG_IOCTL(2, printk("Ioctl returned  0x%x
  ", result));
  
  	if ((driver_byte(result) & DRIVER_SENSE) &&
  	    (scsi_sense_valid(&sshdr))) {
  		switch (sshdr.sense_key) {
  		case ILLEGAL_REQUEST:
  			if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
  				sdev->lockable = 0;
  			else
  				printk(KERN_INFO "ioctl_internal_command: "
  				       "ILLEGAL REQUEST asc=0x%x ascq=0x%x
  ",
  				       sshdr.asc, sshdr.ascq);
  			break;
  		case NOT_READY:	/* This happens if there is no disc in drive */
  			if (sdev->removable)
  				break;
  		case UNIT_ATTENTION:
  			if (sdev->removable) {
  				sdev->changed = 1;
  				result = 0;	/* This is no longer considered an error */
  				break;
  			}
  		default:	/* Fall through for non-removable media */
  			sdev_printk(KERN_INFO, sdev,
  				    "ioctl_internal_command return code = %x
  ",
  				    result);
  			scsi_print_sense_hdr("   ", &sshdr);
  			break;
  		}
  	}
  
  	SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command
  "));
  	return result;
  }
  
  int scsi_set_medium_removal(struct scsi_device *sdev, char state)
  {
  	char scsi_cmd[MAX_COMMAND_SIZE];
  	int ret;
  
  	if (!sdev->removable || !sdev->lockable)
  	       return 0;
  
  	scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
  	scsi_cmd[1] = 0;
  	scsi_cmd[2] = 0;
  	scsi_cmd[3] = 0;
  	scsi_cmd[4] = state;
  	scsi_cmd[5] = 0;
  
  	ret = ioctl_internal_command(sdev, scsi_cmd,
  			IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
  	if (ret == 0)
  		sdev->locked = (state == SCSI_REMOVAL_PREVENT);
  	return ret;
  }
  EXPORT_SYMBOL(scsi_set_medium_removal);
  
  /*
   * The scsi_ioctl_get_pci() function places into arg the value
   * pci_dev::slot_name (8 characters) for the PCI device (if any).
   * Returns: 0 on success
   *          -ENXIO if there isn't a PCI device pointer
   *                 (could be because the SCSI driver hasn't been
   *                  updated yet, or because it isn't a SCSI
   *                  device)
   *          any copy_to_user() error on failure there
   */
  static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
  {
  	struct device *dev = scsi_get_device(sdev->host);
  	const char *name;
  
          if (!dev)
  		return -ENXIO;
  
  	name = dev_name(dev);
  
  	/* compatibility with old ioctl which only returned
  	 * 20 characters */
          return copy_to_user(arg, name, min(strlen(name), (size_t)20))
  		? -EFAULT: 0;
  }
  
  
  /**
   * scsi_ioctl - Dispatch ioctl to scsi device
   * @sdev: scsi device receiving ioctl
   * @cmd: which ioctl is it
   * @arg: data associated with ioctl
   *
   * Description: The scsi_ioctl() function differs from most ioctls in that it
   * does not take a major/minor number as the dev field.  Rather, it takes
   * a pointer to a &struct scsi_device.
   */
  int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
  {
  	char scsi_cmd[MAX_COMMAND_SIZE];
  
  	/* No idea how this happens.... */
  	if (!sdev)
  		return -ENXIO;
  
  	/*
  	 * If we are in the middle of error recovery, don't let anyone
  	 * else try and use this device.  Also, if error recovery fails, it
  	 * may try and take the device offline, in which case all further
  	 * access to the device is prohibited.
  	 */
  	if (!scsi_block_when_processing_errors(sdev))
  		return -ENODEV;
  
  	/* Check for deprecated ioctls ... all the ioctls which don't
  	 * follow the new unique numbering scheme are deprecated */
  	switch (cmd) {
  	case SCSI_IOCTL_SEND_COMMAND:
  	case SCSI_IOCTL_TEST_UNIT_READY:
  	case SCSI_IOCTL_BENCHMARK_COMMAND:
  	case SCSI_IOCTL_SYNC:
  	case SCSI_IOCTL_START_UNIT:
  	case SCSI_IOCTL_STOP_UNIT:
  		printk(KERN_WARNING "program %s is using a deprecated SCSI "
  		       "ioctl, please convert it to SG_IO
  ", current->comm);
  		break;
  	default:
  		break;
  	}
  
  	switch (cmd) {
  	case SCSI_IOCTL_GET_IDLUN:
  		if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
  			return -EFAULT;
  
  		__put_user((sdev->id & 0xff)
  			 + ((sdev->lun & 0xff) << 8)
  			 + ((sdev->channel & 0xff) << 16)
  			 + ((sdev->host->host_no & 0xff) << 24),
  			 &((struct scsi_idlun __user *)arg)->dev_id);
  		__put_user(sdev->host->unique_id,
  			 &((struct scsi_idlun __user *)arg)->host_unique_id);
  		return 0;
  	case SCSI_IOCTL_GET_BUS_NUMBER:
  		return put_user(sdev->host->host_no, (int __user *)arg);
  	case SCSI_IOCTL_PROBE_HOST:
  		return ioctl_probe(sdev->host, arg);
  	case SCSI_IOCTL_SEND_COMMAND:
  		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
  			return -EACCES;
  		return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
  	case SCSI_IOCTL_DOORLOCK:
  		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
  	case SCSI_IOCTL_DOORUNLOCK:
  		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
  	case SCSI_IOCTL_TEST_UNIT_READY:
  		return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
  					    NORMAL_RETRIES, NULL);
  	case SCSI_IOCTL_START_UNIT:
  		scsi_cmd[0] = START_STOP;
  		scsi_cmd[1] = 0;
  		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
  		scsi_cmd[4] = 1;
  		return ioctl_internal_command(sdev, scsi_cmd,
  				     START_STOP_TIMEOUT, NORMAL_RETRIES);
  	case SCSI_IOCTL_STOP_UNIT:
  		scsi_cmd[0] = START_STOP;
  		scsi_cmd[1] = 0;
  		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
  		scsi_cmd[4] = 0;
  		return ioctl_internal_command(sdev, scsi_cmd,
  				     START_STOP_TIMEOUT, NORMAL_RETRIES);
          case SCSI_IOCTL_GET_PCI:
                  return scsi_ioctl_get_pci(sdev, arg);
  	default:
  		if (sdev->host->hostt->ioctl)
  			return sdev->host->hostt->ioctl(sdev, cmd, arg);
  	}
  	return -EINVAL;
  }
  EXPORT_SYMBOL(scsi_ioctl);
  
  /**
   * scsi_nonblockable_ioctl() - Handle SG_SCSI_RESET
   * @sdev: scsi device receiving ioctl
   * @cmd: Must be SC_SCSI_RESET
   * @arg: pointer to int containing SG_SCSI_RESET_{DEVICE,BUS,HOST}
   * @ndelay: file mode O_NDELAY flag
   */
  int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
  			    void __user *arg, int ndelay)
  {
  	int val, result;
  
  	/* The first set of iocts may be executed even if we're doing
  	 * error processing, as long as the device was opened
  	 * non-blocking */
  	if (ndelay) {
  		if (scsi_host_in_recovery(sdev->host))
  			return -ENODEV;
  	} else if (!scsi_block_when_processing_errors(sdev))
  		return -ENODEV;
  
  	switch (cmd) {
  	case SG_SCSI_RESET:
  		result = get_user(val, (int __user *)arg);
  		if (result)
  			return result;
  		if (val == SG_SCSI_RESET_NOTHING)
  			return 0;
  		switch (val) {
  		case SG_SCSI_RESET_DEVICE:
  			val = SCSI_TRY_RESET_DEVICE;
  			break;
  		case SG_SCSI_RESET_TARGET:
  			val = SCSI_TRY_RESET_TARGET;
  			break;
  		case SG_SCSI_RESET_BUS:
  			val = SCSI_TRY_RESET_BUS;
  			break;
  		case SG_SCSI_RESET_HOST:
  			val = SCSI_TRY_RESET_HOST;
  			break;
  		default:
  			return -EINVAL;
  		}
  		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
  			return -EACCES;
  		return (scsi_reset_provider(sdev, val) ==
  			SUCCESS) ? 0 : -EIO;
  	}
  	return -ENODEV;
  }
  EXPORT_SYMBOL(scsi_nonblockable_ioctl);