Re: [PATCH v2] airo: fix setting zero length WEP key

[Dan Williams <dcbw@redhat.com>]

On Thu, 2010-02-04 at 13:07 +0100, Stanislaw Gruszka wrote:
> Patch prevents call set_wep_key() with zero key length. That fix long
> standing regression since commit c0380693520b1a1e4f756799a0edc379378b462a
> "airo: clean up WEP key operations". Additionally print call trace when
> someone will try to use improper parameters, and remove key.len = 0
> assignment, because it is in not possible code path.

Could you send the hunk that touches airo_set_encode() separately
please?  That's obviously correct and an easy ack, but isn't really
related to the other hunks here.

Thanks,
Dan

> v1->v2
> Return instantly from set_wep_key() when keylen == 0.
> 
> Reported-and-bisected-by: Chris Siebenmann <cks-rhbugzilla@cs.toronto.edu>
> Cc: Dan Williams <dcbw@redhat.com>
> Cc: <stable@kernel.org>
> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
> ---
>  drivers/net/wireless/airo.c |   33 ++++++++++++++++++---------------
>  1 files changed, 18 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c
> index 4331d67..01bffc2 100644
> --- a/drivers/net/wireless/airo.c
> +++ b/drivers/net/wireless/airo.c
> @@ -5254,11 +5254,8 @@ static int set_wep_key(struct airo_info *ai, u16 index, const char *key,
>  	WepKeyRid wkr;
>  	int rc;
>  
> -	if (keylen == 0) {
> -		airo_print_err(ai->dev->name, "%s: key length to set was zero",
> -			       __func__);
> +	if (WARN_ON(keylen == 0))
>  		return -1;
> -	}
>  
>  	memset(&wkr, 0, sizeof(wkr));
>  	wkr.len = cpu_to_le16(sizeof(wkr));
> @@ -6405,11 +6402,7 @@ static int airo_set_encode(struct net_device *dev,
>  		if (dwrq->length > MIN_KEY_SIZE)
>  			key.len = MAX_KEY_SIZE;
>  		else
> -			if (dwrq->length > 0)
> -				key.len = MIN_KEY_SIZE;
> -			else
> -				/* Disable the key */
> -				key.len = 0;
> +			key.len = MIN_KEY_SIZE;
>  		/* Check if the key is not marked as invalid */
>  		if(!(dwrq->flags & IW_ENCODE_NOKEY)) {
>  			/* Cleanup */
> @@ -6590,12 +6583,22 @@ static int airo_set_encodeext(struct net_device *dev,
>  		default:
>  			return -EINVAL;
>  		}
> -		/* Send the key to the card */
> -		rc = set_wep_key(local, idx, key.key, key.len, perm, 1);
> -		if (rc < 0) {
> -			airo_print_err(local->dev->name, "failed to set WEP key"
> -			               " at index %d: %d.", idx, rc);
> -			return rc;
> +		if (key.len == 0) {
> +			rc = set_wep_tx_idx(local, idx, perm, 1);
> +			if (rc < 0) {
> +				airo_print_err(local->dev->name,
> +					       "failed to set WEP transmit index to %d: %d.",
> +					       idx, rc);
> +				return rc;
> +			}
> +		} else {
> +			rc = set_wep_key(local, idx, key.key, key.len, perm, 1);
> +			if (rc < 0) {
> +				airo_print_err(local->dev->name,
> +					       "failed to set WEP key at index %d: %d.",
> +					       idx, rc);
> +				return rc;
> +			}
>  		}
>  	}
>