2013-08-21 13:30:50

by Simon Wunderlich

[permalink] [raw]
Subject: [PATCH-mac8011] mac80211: fix ignored channel parameter

my earlier patch "mac80211: change IBSS channel state to chandef"
created a regression by ignoring the channel parameter in
__ieee80211_sta_join_ibss, which breaks IBSS channel selection. This
patch fixes this situation by using the right channel and adopting the
selected bandwidth mode.

Cc: [email protected]
Signed-off-by: Simon Wunderlich <[email protected]>
---
This version is based on mac80211.git for fixes, and the bandwidth
handling was changed in ieee80211_sta_join_ibss to more readable.
---
net/mac80211/ibss.c | 33 +++++++++++++++++++++++++++++----
1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index ea7b9c2..f292e8f 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -36,7 +36,7 @@

static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const int beacon_int,
- struct ieee80211_channel *chan,
+ struct cfg80211_chan_def *req_chandef,
const u32 basic_rates,
const u16 capability, u64 tsf,
bool creator)
@@ -51,6 +51,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
u32 bss_change;
u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
struct cfg80211_chan_def chandef;
+ struct ieee80211_channel *chan;
struct beacon_data *presp;
int frame_len;

@@ -81,7 +82,9 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,

sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;

- chandef = ifibss->chandef;
+ /* make a copy of the chandef, it could be modified below. */
+ chandef = *req_chandef;
+ chan = chandef.chan;
if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
chandef.width = NL80211_CHAN_WIDTH_20;
chandef.center_freq1 = chan->center_freq;
@@ -259,10 +262,12 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
struct cfg80211_bss *cbss =
container_of((void *)bss, struct cfg80211_bss, priv);
struct ieee80211_supported_band *sband;
+ struct cfg80211_chan_def chandef;
u32 basic_rates;
int i, j;
u16 beacon_int = cbss->beacon_interval;
const struct cfg80211_bss_ies *ies;
+ enum nl80211_channel_type chan_type;
u64 tsf;

sdata_assert_lock(sdata);
@@ -270,6 +275,26 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
if (beacon_int < 10)
beacon_int = 10;

+ switch (sdata->u.ibss.chandef.width) {
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ case NL80211_CHAN_WIDTH_20:
+ case NL80211_CHAN_WIDTH_40:
+ chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
+ cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
+ break;
+ case NL80211_CHAN_WIDTH_5:
+ case NL80211_CHAN_WIDTH_10:
+ cfg80211_chandef_create(&chandef, cbss->channel,
+ NL80211_CHAN_WIDTH_20_NOHT);
+ chandef.width = sdata->u.ibss.chandef.width;
+ break;
+ default:
+ /* fall back to 20 MHz for unsupported modes */
+ cfg80211_chandef_create(&chandef, cbss->channel,
+ NL80211_CHAN_WIDTH_20_NOHT);
+ break;
+ }
+
sband = sdata->local->hw.wiphy->bands[cbss->channel->band];

basic_rates = 0;
@@ -294,7 +319,7 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,

__ieee80211_sta_join_ibss(sdata, cbss->bssid,
beacon_int,
- cbss->channel,
+ &chandef,
basic_rates,
cbss->capability,
tsf, false);
@@ -736,7 +761,7 @@ static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
sdata->drop_unencrypted = 0;

__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
- ifibss->chandef.chan, ifibss->basic_rates,
+ &ifibss->chandef, ifibss->basic_rates,
capability, 0, true);
}

--
1.7.10.4



2013-08-21 13:41:29

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH-mac8011] mac80211: fix ignored channel parameter

On Wed, 2013-08-21 at 15:30 +0200, Simon Wunderlich wrote:
> my earlier patch "mac80211: change IBSS channel state to chandef"
> created a regression by ignoring the channel parameter in
> __ieee80211_sta_join_ibss, which breaks IBSS channel selection. This
> patch fixes this situation by using the right channel and adopting the
> selected bandwidth mode.

Tested & applied.

johannes