mac80211: restructure HT code

Create two new files, agg-tx.c and agg-rx.c to make it clearer
which code is common (ht.c) and which is specific (agg-*.c).
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/Makefile

@@ -8,7 +8,7 @@ mac80211-y := \
 	wep.o \
 	wpa.o \
 	scan.o \
-	ht.o \
+	ht.o agg-tx.o agg-rx.o \
 	mlme.o \
 	iface.o \
 	rate.o \

net/mac80211/agg-rx.c

+/*
+ * HT handling
+ *
+ * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005-2006, Devicescape Software, Inc.
+ * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * Copyright 2007-2008, Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ieee80211.h>
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+
+void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
+					u16 initiator, u16 reason)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_hw *hw = &local->hw;
+	struct sta_info *sta;
+	int ret, i;
+
+	rcu_read_lock();
+
+	sta = sta_info_get(local, ra);
+	if (!sta) {
+		rcu_read_unlock();
+		return;
+	}
+
+	/* check if TID is in operational state */
+	spin_lock_bh(&sta->lock);
+	if (sta->ampdu_mlme.tid_state_rx[tid]
+				!= HT_AGG_STATE_OPERATIONAL) {
+		spin_unlock_bh(&sta->lock);
+		rcu_read_unlock();
+		return;
+	}
+	sta->ampdu_mlme.tid_state_rx[tid] =
+		HT_AGG_STATE_REQ_STOP_BA_MSK |
+		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
+	spin_unlock_bh(&sta->lock);
+
+	/* stop HW Rx aggregation. ampdu_action existence
+	 * already verified in session init so we add the BUG_ON */
+	BUG_ON(!local->ops->ampdu_action);
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+	printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
+	       ra, tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+
+	ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_STOP,
+				       &sta->sta, tid, NULL);
+	if (ret)
+		printk(KERN_DEBUG "HW problem - can not stop rx "
+				"aggregation for tid %d\n", tid);
+
+	/* shutdown timer has not expired */
+	if (initiator != WLAN_BACK_TIMER)
+		del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
+
+	/* check if this is a self generated aggregation halt */
+	if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
+		ieee80211_send_delba(sdata, ra, tid, 0, reason);
+
+	/* free the reordering buffer */
+	for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
+		if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
+			/* release the reordered frames */
+			dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
+			sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
+			sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
+		}
+	}
+	/* free resources */
+	kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
+	kfree(sta->ampdu_mlme.tid_rx[tid]);
+	sta->ampdu_mlme.tid_rx[tid] = NULL;
+	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
+
+	rcu_read_unlock();
+}
+
+/*
+ * 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->sta.addr,
+					 (u16)*ptid, WLAN_BACK_TIMER,
+					 WLAN_REASON_QSTA_TIMEOUT);
+}
+
+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 == NL80211_IFTYPE_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_tx_skb(sdata, skb, 1);
+}
+
+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;
+
+	/* 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 */
+	/* XXX: check own ht delayed BA capability?? */
+	if (((ba_policy != 1)
+		&& (!(sta->sta.ht_cap.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 "
+				"%pM on tid %u. policy %d, buffer size %d\n",
+				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_cap.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 "
+				"%pM on tid %u\n",
+				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 =
+		kcalloc(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;
+	}
+
+	if (local->ops->ampdu_action)
+		ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
+					       &sta->sta, 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->sta.addr, tid,
+				  dialog_token, status, 1, buf_size, timeout);
+}

net/mac80211/ieee80211_i.h

@@ -987,6 +987,9 @@ u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
 			struct ieee80211_ht_info *hti,
 			u16 ap_ht_cap_flags);
 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn);
+void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
+			  const u8 *da, u16 tid,
+			  u16 initiator, u16 reason_code);
 
 void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *da,
 				u16 tid, u16 initiator, u16 reason);