Re: [PATCH v2] mac80211: support radiotap vendor namespace RX data

[Wojciech Dubowik <Wojciech.Dubowik@neratec.com>]

On 11/22/2012 09:41 AM, Johannes Berg wrote:
> On Thu, 2012-11-22 at 09:34 +0100, Johannes Berg wrote:
>> On Thu, 2012-11-22 at 09:22 +0100, Wojciech Dubowik wrote:
>>> Shouldn't all functions between ieee80211_rx
>>> and remove_monitor_info map header with
>>> (struct ieee80211_hdr *)(skb->data + status->vendor_radiotap_len) ?
>>>
>>> Otherwise function like should_drop_frame uses header mapped over
>>> potential vendor data.
>> Huh, yes, how did I miss that. It only applies to should_drop_frame()
>> though, or do you see any other place?
> So I think this is sufficient?
I guess so. I will test it today.
Wojtek
>
> johannes
>
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index ec15a49..ec87902 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -62,13 +62,16 @@ static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
>   static inline int should_drop_frame(struct sk_buff *skb, int present_fcs_len)
>   {
>   	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
> -	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
> +	struct ieee80211_hdr *hdr;
> +
> +	hdr = (void *)(skb->data + status->vendor_radiotap_len);
>   
>   	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
>   			    RX_FLAG_FAILED_PLCP_CRC |
>   			    RX_FLAG_AMPDU_IS_ZEROLEN))
>   		return 1;
> -	if (unlikely(skb->len < 16 + present_fcs_len))
> +	if (unlikely(skb->len < 16 + present_fcs_len +
> +				status->vendor_radiotap_len))
>   		return 1;
>   	if (ieee80211_is_ctl(hdr->frame_control) &&
>   	    !ieee80211_is_pspoll(hdr->frame_control) &&
> @@ -341,8 +344,8 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
>   	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
>   		present_fcs_len = FCS_LEN;
>   
> -	/* make sure hdr->frame_control is on the linear part */
> -	if (!pskb_may_pull(origskb, 2)) {
> +	/* ensure hdr->frame_control and vendor radiotap data are in skb head */
> +	if (!pskb_may_pull(origskb, 2 + status->vendor_radiotap_len)) {
>   		dev_kfree_skb(origskb);
>   		return NULL;
>   	}
>
>