2015-01-07 14:21:49

by Arik Nemtsov

Subject: [PATCH v2] mac80211: add TDLS supported channels correctly

The function adding the supported channels IE during a TDLS connection had
several issues:
1. If the entire subband is usable, the function exitted the loop without
adding it
2. The function only checked chandef_usable, ignoring flags like RADAR
which would prevent TDLS off-channel communcation.
3. HT20 was explicitly required in the chandef, while not a requirement
for TDLS off-channel.

Signed-off-by: Arik Nemtsov <[email protected]>
Reviewed-by: Emmanuel Grumbach <[email protected]>
---
net/mac80211/tdls.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index 55ddd77..c5c4342 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -68,17 +68,24 @@ ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
ch = ieee80211_get_channel(sdata->local->hw.wiphy, i);
if (ch) {
/* we will be active on the channel */
- u32 flags = IEEE80211_CHAN_DISABLED |
- IEEE80211_CHAN_NO_IR;
cfg80211_chandef_create(&chandef, ch,
- NL80211_CHAN_HT20);
- if (cfg80211_chandef_usable(sdata->local->hw.wiphy,
- &chandef, flags)) {
+ NL80211_CHAN_NO_HT);
+ if (cfg80211_reg_can_beacon(sdata->local->hw.wiphy,
+ &chandef,
+ sdata->wdev.iftype)) {
ch_cnt++;
+ /*
+ * check if the next channel is also part of
+ * this allowed range */
+ *
continue;
}
}

+ /*
+ * we've reached the end of a range, with allowed channels
+ * found
+ */
if (ch_cnt) {
u8 *pos = skb_put(skb, 2);
*pos++ = ieee80211_frequency_to_channel(subband_start);
@@ -89,6 +96,15 @@ ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
}
}

+ /* all channels in the requested range are allowed - add them here */
+ if (ch_cnt) {
+ u8 *pos = skb_put(skb, 2);
+ *pos++ = ieee80211_frequency_to_channel(subband_start);
+ *pos++ = ch_cnt;
+
+ subband_cnt++;
+ }
+
return subband_cnt;
}

--
2.1.0

2015-01-07 14:29:09

by Arik Nemtsov

Subject: Re: [PATCH v2] mac80211: add TDLS supported channels correctly

On Wed, Jan 7, 2015 at 4:21 PM, Arik Nemtsov <[email protected]> wrote:
> The function adding the supported channels IE during a TDLS connection had
> several issues:
> 1. If the entire subband is usable, the function exitted the loop without
> adding it
> 2. The function only checked chandef_usable, ignoring flags like RADAR
> which would prevent TDLS off-channel communcation.
> 3. HT20 was explicitly required in the chandef, while not a requirement
> for TDLS off-channel.
>
> Signed-off-by: Arik Nemtsov <[email protected]>
> Reviewed-by: Emmanuel Grumbach <[email protected]>
> ---
> net/mac80211/tdls.c | 26 +++++++++++++++++++++-----
> 1 file changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
> index 55ddd77..c5c4342 100644
> --- a/net/mac80211/tdls.c
> +++ b/net/mac80211/tdls.c
> @@ -68,17 +68,24 @@ ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
> ch = ieee80211_get_channel(sdata->local->hw.wiphy, i);
> if (ch) {
> /* we will be active on the channel */
> - u32 flags = IEEE80211_CHAN_DISABLED |
> - IEEE80211_CHAN_NO_IR;
> cfg80211_chandef_create(&chandef, ch,
> - NL80211_CHAN_HT20);
> - if (cfg80211_chandef_usable(sdata->local->hw.wiphy,
> - &chandef, flags)) {
> + NL80211_CHAN_NO_HT);
> + if (cfg80211_reg_can_beacon(sdata->local->hw.wiphy,
> + &chandef,
> + sdata->wdev.iftype)) {
> ch_cnt++;
> + /*
> + * check if the next channel is also part of
> + * this allowed range */
> + *

argh. resending. this wasn't compiled properly :)