mac80211: handle protection mode, RIFS and ADDBA for HT IBSS

* Follow 802.11n-2009 9.13.3.1 for protection mode and ADDBA
* Send ADDBA only to HT STAs - implement 11.5.1.1 partially

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 2c2e9519a2e73bcd4b3ba0f7618ae2c723f2494a..9bfe28c9ab59d87d7012c73841870d7f24204418 100644 (file)
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -430,6 +430,27 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
                return -EINVAL;
        }
 
+       /*
+        * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
+        * member of an IBSS, and has no other existing Block Ack agreement
+        * with the recipient STA, then the initiating STA shall transmit a
+        * Probe Request frame to the recipient STA and shall not transmit an
+        * ADDBA Request frame unless it receives a Probe Response frame
+        * from the recipient within dot11ADDBAFailureTimeout.
+        *
+        * The probe request mechanism for ADDBA is currently not implemented,
+        * but we only build up Block Ack session with HT STAs. This information
+        * is set when we receive a bss info from a probe response or a beacon.
+        */
+       if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
+           !sta->sta.ht_cap.ht_supported) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+               printk(KERN_DEBUG "BA request denied - IBSS STA %pM"
+                      "does not advertise HT support\n", pubsta->addr);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+               return -EINVAL;
+       }
+
        spin_lock_bh(&sta->lock);
 
        /* we have tried too many times, receiver does not want A-MPDU */

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 7d84af70132f8f0b4a6cdbbf80876b71cdca24c4..a82f6b4adb589695fd8bb665e91351c36b491993 100644 (file)
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -896,6 +896,7 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
                        struct cfg80211_ibss_params *params)
 {
        struct sk_buff *skb;
+       u32 changed = 0;
 
        skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
                            36 /* bitrates */ +
@@ -951,6 +952,23 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
        ieee80211_recalc_idle(sdata->local);
        mutex_unlock(&sdata->local->mtx);
 
+       /*
+        * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
+        * reserved, but an HT STA shall protect HT transmissions as though
+        * the HT Protection field were set to non-HT mixed mode.
+        *
+        * In an IBSS, the RIFS Mode field of the HT Operation element is
+        * also reserved, but an HT STA shall operate as though this field
+        * were set to 1.
+        */
+
+       sdata->vif.bss_conf.ht_operation_mode |=
+                 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
+               | IEEE80211_HT_PARAM_RIFS_MODE;
+
+       changed |= BSS_CHANGED_HT;
+       ieee80211_bss_info_change_notify(sdata, changed);
+
        ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 
        return 0;

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 5243c2cadeef7d175acc7528d253d79a6a9f9a21..ac7ea2949de0ae870ccc445f872f50e140d58857 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1587,6 +1587,11 @@ u8 *ieee80211_ie_build_ht_info(u8 *pos,
        }
        if (ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40)
                ht_info->ht_param |= IEEE80211_HT_PARAM_CHAN_WIDTH_ANY;
+
+       /*
+        * Note: According to 802.11n-2009 9.13.3.1, HT Protection field and
+        * RIFS Mode are reserved in IBSS mode, therefore keep them at 0
+        */
        ht_info->operation_mode = 0x0000;
        ht_info->stbc_param = 0x0000;