2015-01-19 04:04:58

by Fred Chou

Subject: [PATCH] mac80211: correct header length calculation

From: Fred Chou <[email protected]>

HT Control field may also be present in management frames, as defined
in 8.2.4.1.10 of 802.11-2012. Account for this in calculation of
header length.

Signed-off-by: Fred Chou <[email protected]>
---
net/wireless/util.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 1d2fcfa..ce9617c 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -297,6 +297,12 @@ unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
{
unsigned int hdrlen = 24;

+ if (ieee80211_is_mgmt(fc)) {
+ if (ieee80211_has_order(fc))
+ hdrlen += IEEE80211_HT_CTL_LEN;
+ goto out;
+ }
+
if (ieee80211_is_data(fc)) {
if (ieee80211_has_a4(fc))
hdrlen = 30;
--
1.9.1

2015-01-19 09:58:29

by Johannes Berg

Subject: Re: [PATCH] mac80211: correct header length calculation

On Mon, 2015-01-19 at 12:07 +0800, Fred Chou wrote:
> From: Fred Chou <[email protected]>
>
> HT Control field may also be present in management frames, as defined
> in 8.2.4.1.10 of 802.11-2012. Account for this in calculation of
> header length.
>
> Signed-off-by: Fred Chou <[email protected]>
> ---
> net/wireless/util.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/net/wireless/util.c b/net/wireless/util.c
> index 1d2fcfa..ce9617c 100644
> --- a/net/wireless/util.c
> +++ b/net/wireless/util.c
> @@ -297,6 +297,12 @@ unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
> {
> unsigned int hdrlen = 24;
>
> + if (ieee80211_is_mgmt(fc)) {
> + if (ieee80211_has_order(fc))
> + hdrlen += IEEE80211_HT_CTL_LEN;
> + goto out;
> + }
> +
> if (ieee80211_is_data(fc)) {

I think you should insert this after data since data frames are more
common.

johannes