/**
 * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
 * @file:	file this ioctl operates on (optional)
 * @q:		request queue to send scsi commands down
 * @disk:	gendisk to operate on (option)
 * @sic:	userspace structure describing the command to perform
 *
 * Send down the scsi command described by @sic to the device below
 * the request queue @q.  If @file is non-NULL it's used to perform
 * fine-grained permission checks that allow users to send down
 * non-destructive SCSI commands.  If the caller has a struct gendisk
 * available it should be passed in as @disk to allow the low level
 * driver to use the information contained in it.  A non-NULL @disk
 * is only allowed if the caller knows that the low level driver doesn't
 * need it (e.g. in the scsi subsystem).
 *
 * Notes:
 *   -  This interface is deprecated - users should use the SG_IO
 *      interface instead, as this is a more flexible approach to
 *      performing SCSI commands on a device.
 *   -  The SCSI command length is determined by examining the 1st byte
 *      of the given command. There is no way to override this.
 *   -  Data transfers are limited to PAGE_SIZE
 *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 *      accommodate the sense buffer when an error occurs.
 *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 *      old code will not be surprised.
 *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 *      a negative return and the Unix error code in 'errno'.
 *      If the SCSI command succeeds then 0 is returned.
 *      Positive numbers returned are the compacted SCSI error codes (4
 *      bytes in one int) where the lowest byte is the SCSI status.
 */
#define OMAX_SB_LEN 16          /* For backward compatibility */
int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
		struct scsi_ioctl_command __user *sic)
{
	struct request *rq;
	int err;
	unsigned int in_len, out_len, bytes, opcode, cmdlen;
	char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];

	if (!sic)
		return -EINVAL;

	/*
	 * get in an out lengths, verify they don't exceed a page worth of data
	 */
	if (get_user(in_len, &sic->inlen))
		return -EFAULT;
	if (get_user(out_len, &sic->outlen))
		return -EFAULT;
	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
		return -EINVAL;
	if (get_user(opcode, sic->data))
		return -EFAULT;

	bytes = max(in_len, out_len);
	if (bytes) {
		buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
		if (!buffer)
			return -ENOMEM;

	}

	rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);

	cmdlen = COMMAND_SIZE(opcode);

	/*
	 * get command and data to send to device, if any
	 */
	err = -EFAULT;
	rq->cmd_len = cmdlen;
	if (copy_from_user(rq->cmd, sic->data, cmdlen))
		goto error;

	if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
		goto error;

	err = blk_verify_command(rq->cmd, mode & FMODE_WRITE);
	if (err)
		goto error;

	/* default.  possible overriden later */
	rq->retries = 5;

	switch (opcode) {
	case SEND_DIAGNOSTIC:
	case FORMAT_UNIT:
		rq->timeout = FORMAT_UNIT_TIMEOUT;
		rq->retries = 1;
		break;
	case START_STOP:
		rq->timeout = START_STOP_TIMEOUT;
		break;
	case MOVE_MEDIUM:
		rq->timeout = MOVE_MEDIUM_TIMEOUT;
		break;
	case READ_ELEMENT_STATUS:
		rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
		break;
	case READ_DEFECT_DATA:
		rq->timeout = READ_DEFECT_DATA_TIMEOUT;
		rq->retries = 1;
		break;
	default:
		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
		break;
	}

	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_WAIT)) {
		err = DRIVER_ERROR << 24;
		goto out;
	}

	memset(sense, 0, sizeof(sense));
	rq->sense = sense;
	rq->sense_len = 0;
	rq->cmd_type = REQ_TYPE_BLOCK_PC;

	blk_execute_rq(q, disk, rq, 0);

out:
	err = rq->errors & 0xff;	/* only 8 bit SCSI status */
	if (err) {
		if (rq->sense_len && rq->sense) {
			bytes = (OMAX_SB_LEN > rq->sense_len) ?
				rq->sense_len : OMAX_SB_LEN;
			if (copy_to_user(sic->data, rq->sense, bytes))
				err = -EFAULT;
		}
	} else {
		if (copy_to_user(sic->data, buffer, out_len))
			err = -EFAULT;
	}
	
error:
	kfree(buffer);
	blk_put_request(rq);
	return err;
}
Пример #2
0
/**
 * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
 * @q:		request queue to send scsi commands down
 * @disk:	gendisk to operate on (option)
 * @mode:	mode used to open the file through which the ioctl has been
 *		submitted
 * @sic:	userspace structure describing the command to perform
 *
 * Send down the scsi command described by @sic to the device below
 * the request queue @q.  If @file is non-NULL it's used to perform
 * fine-grained permission checks that allow users to send down
 * non-destructive SCSI commands.  If the caller has a struct gendisk
 * available it should be passed in as @disk to allow the low level
 * driver to use the information contained in it.  A non-NULL @disk
 * is only allowed if the caller knows that the low level driver doesn't
 * need it (e.g. in the scsi subsystem).
 *
 * Notes:
 *   -  This interface is deprecated - users should use the SG_IO
 *      interface instead, as this is a more flexible approach to
 *      performing SCSI commands on a device.
 *   -  The SCSI command length is determined by examining the 1st byte
 *      of the given command. There is no way to override this.
 *   -  Data transfers are limited to PAGE_SIZE
 *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 *      accommodate the sense buffer when an error occurs.
 *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 *      old code will not be surprised.
 *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 *      a negative return and the Unix error code in 'errno'.
 *      If the SCSI command succeeds then 0 is returned.
 *      Positive numbers returned are the compacted SCSI error codes (4
 *      bytes in one int) where the lowest byte is the SCSI status.
 */
int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
		struct scsi_ioctl_command __user *sic)
{
	enum { OMAX_SB_LEN = 16 };	/* For backward compatibility */
	struct request *rq;
	struct scsi_request *req;
	int err;
	unsigned int in_len, out_len, bytes, opcode, cmdlen;
	char *buffer = NULL;

	if (!sic)
		return -EINVAL;

	/*
	 * get in an out lengths, verify they don't exceed a page worth of data
	 */
	if (get_user(in_len, &sic->inlen))
		return -EFAULT;
	if (get_user(out_len, &sic->outlen))
		return -EFAULT;
	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
		return -EINVAL;
	if (get_user(opcode, sic->data))
		return -EFAULT;

	bytes = max(in_len, out_len);
	if (bytes) {
		buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
		if (!buffer)
			return -ENOMEM;

	}

	rq = blk_get_request(q, in_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
	if (IS_ERR(rq)) {
		err = PTR_ERR(rq);
		goto error_free_buffer;
	}
	req = scsi_req(rq);

	cmdlen = COMMAND_SIZE(opcode);

	/*
	 * get command and data to send to device, if any
	 */
	err = -EFAULT;
	req->cmd_len = cmdlen;
	if (copy_from_user(req->cmd, sic->data, cmdlen))
		goto error;

	if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
		goto error;

	err = blk_verify_command(req->cmd, mode);
	if (err)
		goto error;

	/* default.  possible overriden later */
	req->retries = 5;

	switch (opcode) {
	case SEND_DIAGNOSTIC:
	case FORMAT_UNIT:
		rq->timeout = FORMAT_UNIT_TIMEOUT;
		req->retries = 1;
		break;
	case START_STOP:
		rq->timeout = START_STOP_TIMEOUT;
		break;
	case MOVE_MEDIUM:
		rq->timeout = MOVE_MEDIUM_TIMEOUT;
		break;
	case READ_ELEMENT_STATUS:
		rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
		break;
	case READ_DEFECT_DATA:
		rq->timeout = READ_DEFECT_DATA_TIMEOUT;
		req->retries = 1;
		break;
	default:
		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
		break;
	}

	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, GFP_NOIO)) {
		err = DRIVER_ERROR << 24;
		goto error;
	}

	blk_execute_rq(q, disk, rq, 0);

	err = req->result & 0xff;	/* only 8 bit SCSI status */
	if (err) {
		if (req->sense_len && req->sense) {
			bytes = (OMAX_SB_LEN > req->sense_len) ?
				req->sense_len : OMAX_SB_LEN;
			if (copy_to_user(sic->data, req->sense, bytes))
				err = -EFAULT;
		}
	} else {
		if (copy_to_user(sic->data, buffer, out_len))
			err = -EFAULT;
	}
	
error:
	blk_put_request(rq);

error_free_buffer:
	kfree(buffer);

	return err;
}