From 22f66895e60cfc55b92f6fa93f05bb3fbdbd0bed Mon Sep 17 00:00:00 2001 From: Avri Altman Date: Tue, 18 Aug 2015 16:52:07 +0300 Subject: [PATCH] mac80211: protect non-HT BSS when HT TDLS traffic exists HT TDLS traffic should be protected in a non-HT BSS to avoid collisions. Therefore, when TDLS peers join/leave, check if protection is (now) needed and set the ht_operation_mode of the virtual interface according to the HT capabilities of the TDLS peer(s). This works because a non-HT BSS connection never sets (or otherwise uses) the ht_operation_mode; it just means that drivers must be aware that this field applies to all HT traffic for this virtual interface, not just the traffic within the BSS. Document that. Signed-off-by: Avri Altman Signed-off-by: Johannes Berg --- include/net/mac80211.h | 4 ++- net/mac80211/tdls.c | 70 ++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 70 insertions(+), 4 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index e3314e516681..bfc569498bfa 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -477,7 +477,9 @@ struct ieee80211_event { * @chandef: Channel definition for this BSS -- the hardware might be * configured a higher bandwidth than this BSS uses, for example. * @ht_operation_mode: HT operation mode like in &struct ieee80211_ht_operation. - * This field is only valid when the channel type is one of the HT types. + * This field is only valid when the channel is a wide HT/VHT channel. + * Note that with TDLS this can be the case (channel is HT, protection must + * be used from this field) even when the BSS association isn't using HT. * @cqm_rssi_thold: Connection quality monitor RSSI threshold, a zero value * implies disabled * @cqm_rssi_hyst: Connection quality monitor RSSI hysteresis diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c index aee701a5649e..4e202d0679b2 100644 --- a/net/mac80211/tdls.c +++ b/net/mac80211/tdls.c @@ -1249,6 +1249,58 @@ static void iee80211_tdls_recalc_chanctx(struct ieee80211_sub_if_data *sdata) mutex_unlock(&local->chanctx_mtx); } +static int iee80211_tdls_have_ht_peers(struct ieee80211_sub_if_data *sdata) +{ + struct sta_info *sta; + bool result = false; + + rcu_read_lock(); + list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) { + if (!sta->sta.tdls || sta->sdata != sdata || !sta->uploaded || + !test_sta_flag(sta, WLAN_STA_AUTHORIZED) || + !test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH) || + !sta->sta.ht_cap.ht_supported) + continue; + result = true; + break; + } + rcu_read_unlock(); + + return result; +} + +static void +iee80211_tdls_recalc_ht_protection(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta) +{ + struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; + bool tdls_ht; + u16 protection = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED | + IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT | + IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT; + u16 opmode; + + /* Nothing to do if the BSS connection uses HT */ + if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) + return; + + tdls_ht = (sta && sta->sta.ht_cap.ht_supported) || + iee80211_tdls_have_ht_peers(sdata); + + opmode = sdata->vif.bss_conf.ht_operation_mode; + + if (tdls_ht) + opmode |= protection; + else + opmode &= ~protection; + + if (opmode == sdata->vif.bss_conf.ht_operation_mode) + return; + + sdata->vif.bss_conf.ht_operation_mode = opmode; + ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_HT); +} + int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, const u8 *peer, enum nl80211_tdls_operation oper) { @@ -1274,6 +1326,10 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, return -ENOTSUPP; } + /* protect possible bss_conf changes and avoid concurrency in + * ieee80211_bss_info_change_notify() + */ + sdata_lock(sdata); mutex_lock(&local->mtx); tdls_dbg(sdata, "TDLS oper %d peer %pM\n", oper, peer); @@ -1287,16 +1343,18 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, iee80211_tdls_recalc_chanctx(sdata); - rcu_read_lock(); + mutex_lock(&local->sta_mtx); sta = sta_info_get(sdata, peer); if (!sta) { - rcu_read_unlock(); + mutex_unlock(&local->sta_mtx); ret = -ENOLINK; break; } + iee80211_tdls_recalc_ht_protection(sdata, sta); + set_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH); - rcu_read_unlock(); + mutex_unlock(&local->sta_mtx); WARN_ON_ONCE(is_zero_ether_addr(sdata->u.mgd.tdls_peer) || !ether_addr_equal(sdata->u.mgd.tdls_peer, peer)); @@ -1318,6 +1376,11 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, ieee80211_flush_queues(local, sdata, false); ret = sta_info_destroy_addr(sdata, peer); + + mutex_lock(&local->sta_mtx); + iee80211_tdls_recalc_ht_protection(sdata, NULL); + mutex_unlock(&local->sta_mtx); + iee80211_tdls_recalc_chanctx(sdata); break; default: @@ -1335,6 +1398,7 @@ int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev, &sdata->u.mgd.request_smps_work); mutex_unlock(&local->mtx); + sdata_unlock(sdata); return ret; } -- 2.30.2