# Re: \[RFC PATCH 1/5\] libfcoe, fcoe: Allow user to set a ctlr's mode

- From: Bart Van Assche \<bvanassche@acm.org\>
- Date: 2012-09-11 05:51:47 
- List: netdev
- Page: https://ratatoskr.run/netdev/2012/09/6698759
- Thread: https://ratatoskr.run/netdev/2012/09/6698751/t.md

```text
On 09/11/12 00:59, Robert Love wrote:
> +static enum fip_conn_type fcoe_parse_mode(const char *buf,
> +				  const struct fcoe_ctlr_mode_table *tbl)
> +{
> +	int modeint = -1, i, rv;
> +	char *p, modestr[FCOE_MAX_MODENAME_LEN + 1] = { 0, };
> +
> +	for (p = (char *)buf; *p; p++)
> +		if (!(isdigit(*p) || isspace(*p)))
> +			break;

If you change the declaration of p from "char *p" into "const char *p"
you won't need a cast in the above for loop.

[ ... ]

> -static FCOE_DEVICE_ATTR(ctlr, mode, S_IRUGO,
> -			show_ctlr_mode, NULL);
> +
> +static ssize_t store_ctlr_mode(struct device *dev,
> +			       struct device_attribute *attr,
> +			       const char *buf, size_t count)
> +{
> +	struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
> +
> +	if (!ctlr->f->set_fcoe_ctlr_mode)
> +		return -EINVAL;
> +
> +	ctlr->mode = fcoe_parse_mode(buf, ctlr_mode_tbl);

As far as I know sysfs doesn't terminate buf with a '\0' before calling
a store method. Does that mean that you are passing a string that is not
'\0'-terminated to a function that expects a '\0'-terminated string ?

Bart.
```