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>

1 files changed, 287 insertions, 0 deletions

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
new file mode 100644
index 000000000000..62b9feb3c804
--- /dev/null
+++ b/net/mac80211/agg-rx.c
@@ -0,0 +1,287 @@
+/*
+ * 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);
+}