mac80211: make BA session handling independent of STA mode

The aggregation handling isn't dependent on anything related to our
STA-mode implementation, and doesn't need to depend on it for frame
processing. This patch moves the relevant code to ht.c and adds a
hook in rx.c. For now, the relevant action frames are only processed
in STA/IBSS modes, but that's now something we can easily change.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 297 insertions, 6 deletions

diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index c72b3fe3ccdb..7e93e1079ade 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -66,9 +66,10 @@ int ieee80211_ht_addt_info_ie_to_ht_bss_info(
 	return 0;
 }
 
-void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, const u8 *da,
-				u16 tid, u8 dialog_token, u16 start_seq_num,
-				u16 agg_size, u16 timeout)
+static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
+					 const u8 *da, u16 tid,
+					 u8 dialog_token, u16 start_seq_num,
+					 u16 agg_size, u16 timeout)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
@@ -115,8 +116,55 @@ void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, const u8
 	ieee80211_sta_tx(sdata, skb, 0);
 }
 
-void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata, const u8 *da, u16 tid,
-			  u16 initiator, u16 reason_code)
+static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
+				      u8 dialog_token, u16 status, u16 policy,
+				      u16 buf_size, u16 timeout)
+{
+	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+	struct ieee80211_local *local = sdata->local;
+	struct sk_buff *skb;
+	struct ieee80211_mgmt *mgmt;
+	u16 capab;
+
+	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
+
+	if (!skb) {
+		printk(KERN_DEBUG "%s: failed to allocate buffer "
+		       "for addba resp frame\n", sdata->dev->name);
+		return;
+	}
+
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
+	memset(mgmt, 0, 24);
+	memcpy(mgmt->da, da, ETH_ALEN);
+	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
+	if (sdata->vif.type == IEEE80211_IF_TYPE_AP)
+		memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
+	else
+		memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
+	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+					  IEEE80211_STYPE_ACTION);
+
+	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
+	mgmt->u.action.category = WLAN_CATEGORY_BACK;
+	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
+	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
+
+	capab = (u16)(policy << 1);	/* bit 1 aggregation policy */
+	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
+	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */
+
+	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
+	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
+	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
+
+	ieee80211_sta_tx(sdata, skb, 0);
+}
+
+static void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
+				 const u8 *da, u16 tid,
+				 u16 initiator, u16 reason_code)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_sta *ifsta = &sdata->u.sta;
@@ -263,7 +311,7 @@ void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *r
  * add Block Ack response will arrive from the recipient.
  * If this timer expires sta_addba_resp_timer_expired will be executed.
  */
-void sta_addba_resp_timer_expired(unsigned long data)
+static void sta_addba_resp_timer_expired(unsigned long data)
 {
 	/* not an elegant detour, but there is no choice as the timer passes
 	 * only one argument, and both sta_info and TID are needed, so init
@@ -699,3 +747,246 @@ void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 	tasklet_schedule(&local->tasklet);
 }
 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
+
+/*
+ * After accepting the AddBA Request we activated a timer,
+ * resetting it after each frame that arrives from the originator.
+ * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
+ */
+static void sta_rx_agg_session_timer_expired(unsigned long data)
+{
+	/* not an elegant detour, but there is no choice as the timer passes
+	 * only one argument, and various sta_info are needed here, so init
+	 * flow in sta_info_create gives the TID as data, while the timer_to_id
+	 * array gives the sta through container_of */
+	u8 *ptid = (u8 *)data;
+	u8 *timer_to_id = ptid - *ptid;
+	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
+					 timer_to_tid[0]);
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+	printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
+#endif
+	ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->addr,
+					 (u16)*ptid, WLAN_BACK_TIMER,
+					 WLAN_REASON_QSTA_TIMEOUT);
+}
+
+void ieee80211_process_addba_request(struct ieee80211_local *local,
+				     struct sta_info *sta,
+				     struct ieee80211_mgmt *mgmt,
+				     size_t len)
+{
+	struct ieee80211_hw *hw = &local->hw;
+	struct ieee80211_conf *conf = &hw->conf;
+	struct tid_ampdu_rx *tid_agg_rx;
+	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
+	u8 dialog_token;
+	int ret = -EOPNOTSUPP;
+	DECLARE_MAC_BUF(mac);
+
+	/* extract session parameters from addba request frame */
+	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
+	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
+	start_seq_num =
+		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
+
+	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
+	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
+	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
+	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
+
+	status = WLAN_STATUS_REQUEST_DECLINED;
+
+	/* sanity check for incoming parameters:
+	 * check if configuration can support the BA policy
+	 * and if buffer size does not exceeds max value */
+	if (((ba_policy != 1)
+		&& (!(conf->ht_conf.cap & IEEE80211_HT_CAP_DELAY_BA)))
+		|| (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
+		status = WLAN_STATUS_INVALID_QOS_PARAM;
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		if (net_ratelimit())
+			printk(KERN_DEBUG "AddBA Req with bad params from "
+				"%s on tid %u. policy %d, buffer size %d\n",
+				print_mac(mac, mgmt->sa), tid, ba_policy,
+				buf_size);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+		goto end_no_lock;
+	}
+	/* determine default buffer size */
+	if (buf_size == 0) {
+		struct ieee80211_supported_band *sband;
+
+		sband = local->hw.wiphy->bands[conf->channel->band];
+		buf_size = IEEE80211_MIN_AMPDU_BUF;
+		buf_size = buf_size << sband->ht_info.ampdu_factor;
+	}
+
+
+	/* examine state machine */
+	spin_lock_bh(&sta->lock);
+
+	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		if (net_ratelimit())
+			printk(KERN_DEBUG "unexpected AddBA Req from "
+				"%s on tid %u\n",
+				print_mac(mac, mgmt->sa), tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+		goto end;
+	}
+
+	/* prepare A-MPDU MLME for Rx aggregation */
+	sta->ampdu_mlme.tid_rx[tid] =
+			kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
+	if (!sta->ampdu_mlme.tid_rx[tid]) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		if (net_ratelimit())
+			printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
+					tid);
+#endif
+		goto end;
+	}
+	/* rx timer */
+	sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
+				sta_rx_agg_session_timer_expired;
+	sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
+				(unsigned long)&sta->timer_to_tid[tid];
+	init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
+
+	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
+
+	/* prepare reordering buffer */
+	tid_agg_rx->reorder_buf =
+		kmalloc(buf_size * sizeof(struct sk_buff *), GFP_ATOMIC);
+	if (!tid_agg_rx->reorder_buf) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		if (net_ratelimit())
+			printk(KERN_ERR "can not allocate reordering buffer "
+			       "to tid %d\n", tid);
+#endif
+		kfree(sta->ampdu_mlme.tid_rx[tid]);
+		goto end;
+	}
+	memset(tid_agg_rx->reorder_buf, 0,
+		buf_size * sizeof(struct sk_buff *));
+
+	if (local->ops->ampdu_action)
+		ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
+					       sta->addr, tid, &start_seq_num);
+#ifdef CONFIG_MAC80211_HT_DEBUG
+	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+
+	if (ret) {
+		kfree(tid_agg_rx->reorder_buf);
+		kfree(tid_agg_rx);
+		sta->ampdu_mlme.tid_rx[tid] = NULL;
+		goto end;
+	}
+
+	/* change state and send addba resp */
+	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
+	tid_agg_rx->dialog_token = dialog_token;
+	tid_agg_rx->ssn = start_seq_num;
+	tid_agg_rx->head_seq_num = start_seq_num;
+	tid_agg_rx->buf_size = buf_size;
+	tid_agg_rx->timeout = timeout;
+	tid_agg_rx->stored_mpdu_num = 0;
+	status = WLAN_STATUS_SUCCESS;
+end:
+	spin_unlock_bh(&sta->lock);
+
+end_no_lock:
+	ieee80211_send_addba_resp(sta->sdata, sta->addr, tid,
+				  dialog_token, status, 1, buf_size, timeout);
+}
+
+void ieee80211_process_addba_resp(struct ieee80211_local *local,
+				  struct sta_info *sta,
+				  struct ieee80211_mgmt *mgmt,
+				  size_t len)
+{
+	struct ieee80211_hw *hw = &local->hw;
+	u16 capab;
+	u16 tid;
+	u8 *state;
+
+	capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
+	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
+
+	state = &sta->ampdu_mlme.tid_state_tx[tid];
+
+	spin_lock_bh(&sta->lock);
+
+	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
+		spin_unlock_bh(&sta->lock);
+		return;
+	}
+
+	if (mgmt->u.action.u.addba_resp.dialog_token !=
+		sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
+		spin_unlock_bh(&sta->lock);
+#ifdef CONFIG_MAC80211_HT_DEBUG
+		printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+		return;
+	}
+
+	del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
+#ifdef CONFIG_MAC80211_HT_DEBUG
+	printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+	if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
+			== WLAN_STATUS_SUCCESS) {
+		*state |= HT_ADDBA_RECEIVED_MSK;
+		sta->ampdu_mlme.addba_req_num[tid] = 0;
+
+		if (*state == HT_AGG_STATE_OPERATIONAL)
+			ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
+
+		spin_unlock_bh(&sta->lock);
+	} else {
+		sta->ampdu_mlme.addba_req_num[tid]++;
+		/* this will allow the state check in stop_BA_session */
+		*state = HT_AGG_STATE_OPERATIONAL;
+		spin_unlock_bh(&sta->lock);
+		ieee80211_stop_tx_ba_session(hw, sta->addr, tid,
+					     WLAN_BACK_INITIATOR);
+	}
+}
+
+void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
+			     struct sta_info *sta,
+			     struct ieee80211_mgmt *mgmt, size_t len)
+{
+	struct ieee80211_local *local = sdata->local;
+	u16 tid, params;
+	u16 initiator;
+	DECLARE_MAC_BUF(mac);
+
+	params = le16_to_cpu(mgmt->u.action.u.delba.params);
+	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
+	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+	if (net_ratelimit())
+		printk(KERN_DEBUG "delba from %s (%s) tid %d reason code %d\n",
+			print_mac(mac, mgmt->sa),
+			initiator ? "initiator" : "recipient", tid,
+			mgmt->u.action.u.delba.reason_code);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+
+	if (initiator == WLAN_BACK_INITIATOR)
+		ieee80211_sta_stop_rx_ba_session(sdata, sta->addr, tid,
+						 WLAN_BACK_INITIATOR, 0);
+	else { /* WLAN_BACK_RECIPIENT */
+		spin_lock_bh(&sta->lock);
+		sta->ampdu_mlme.tid_state_tx[tid] =
+				HT_AGG_STATE_OPERATIONAL;
+		spin_unlock_bh(&sta->lock);
+		ieee80211_stop_tx_ba_session(&local->hw, sta->addr, tid,
+					     WLAN_BACK_RECIPIENT);
+	}
+}