Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b580781e038968fb2529460e8b61e3bf77de112a
Commit: b580781e038968fb2529460e8b61e3bf77de112a
Parent: 16c5f15c73e97e22a1fcc6518da32bdcf98aec3d
Author: Ron Rindjunsky <[EMAIL PROTECTED]>
AuthorDate: Tue Dec 25 17:00:35 2007 +0200
Committer: David S. Miller <[EMAIL PROTECTED]>
CommitDate: Mon Jan 28 15:01:00 2008 -0800
mac80211: A-MPDU Rx handling aggregation reordering
This patch handles the reordering of the Rx A-MPDU.
This issue occurs when the sequence of the internal MPDUs is not in the
right order. such a case can be encountered for example when some MPDUs from
previous aggregations were recieved, while others failed, so current A-MPDU
will contain a mix of re-transmited MPDUs and new ones.
Signed-off-by: Ron Rindjunsky <[EMAIL PROTECTED]>
Signed-off-by: John W. Linville <[EMAIL PROTECTED]>
Signed-off-by: David S. Miller <[EMAIL PROTECTED]>
---
net/mac80211/ieee80211_sta.c | 10 ++-
net/mac80211/rx.c | 185 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 192 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
index d5a7683..f1edaa0 100644
--- a/net/mac80211/ieee80211_sta.c
+++ b/net/mac80211/ieee80211_sta.c
@@ -1208,7 +1208,7 @@ void ieee80211_sta_stop_rx_ba_session(struct net_device
*dev, u8 *ra, u16 tid,
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
struct sta_info *sta;
- int ret;
+ int ret, i;
sta = sta_info_get(local, ra);
if (!sta)
@@ -1250,6 +1250,14 @@ void ieee80211_sta_stop_rx_ba_session(struct net_device
*dev, u8 *ra, u16 tid,
ieee80211_send_delba(dev, 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;
+ }
+ }
kfree(sta->ampdu_mlme.tid_rx[tid].reorder_buf);
sta->ampdu_mlme.tid_rx[tid].state = HT_AGG_STATE_IDLE;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index a58a94b..e7b1eb8 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -330,7 +330,6 @@ u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
/* Divide channel_use by 8 to avoid wrapping around the counter */
load >>= CHAN_UTIL_SHIFT;
- local->channel_use_raw += load;
return load;
}
@@ -1749,6 +1748,186 @@ void __ieee80211_rx_handle_packet(struct ieee80211_hw
*hw, struct sk_buff *skb,
sta_info_put(sta);
}
+#define SEQ_MODULO 0x1000
+#define SEQ_MASK 0xfff
+
+static inline int seq_less(u16 sq1, u16 sq2)
+{
+ return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
+}
+
+static inline u16 seq_inc(u16 sq)
+{
+ return ((sq + 1) & SEQ_MASK);
+}
+
+static inline u16 seq_sub(u16 sq1, u16 sq2)
+{
+ return ((sq1 - sq2) & SEQ_MASK);
+}
+
+
+u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
+ struct tid_ampdu_rx *tid_agg_rx,
+ struct sk_buff *skb, u16 mpdu_seq_num,
+ int bar_req)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+ struct ieee80211_rx_status status;
+ u16 head_seq_num, buf_size;
+ int index;
+ u32 pkt_load;
+
+ buf_size = tid_agg_rx->buf_size;
+ head_seq_num = tid_agg_rx->head_seq_num;
+
+ /* frame with out of date sequence number */
+ if (seq_less(mpdu_seq_num, head_seq_num)) {
+ dev_kfree_skb(skb);
+ return 1;
+ }
+
+ /* if frame sequence number exceeds our buffering window size or
+ * block Ack Request arrived - release stored frames */
+ if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
+ /* new head to the ordering buffer */
+ if (bar_req)
+ head_seq_num = mpdu_seq_num;
+ else
+ head_seq_num =
+ seq_inc(seq_sub(mpdu_seq_num, buf_size));
+ /* release stored frames up to new head to stack */
+ while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
+ index = seq_sub(tid_agg_rx->head_seq_num,
+ tid_agg_rx->ssn)
+ % tid_agg_rx->buf_size;
+
+ if (tid_agg_rx->reorder_buf[index]) {
+ /* release the reordered frames to stack */
+ memcpy(&status,
+ tid_agg_rx->reorder_buf[index]->cb,
+ sizeof(status));
+ pkt_load = ieee80211_rx_load_stats(local,
+ tid_agg_rx->reorder_buf[index],
+ &status);
+ __ieee80211_rx_handle_packet(hw,
+ tid_agg_rx->reorder_buf[index],
+ &status, pkt_load);
+ tid_agg_rx->stored_mpdu_num--;
+ tid_agg_rx->reorder_buf[index] = NULL;
+ }
+ tid_agg_rx->head_seq_num =
+ seq_inc(tid_agg_rx->head_seq_num);
+ }
+ if (bar_req)
+ return 1;
+ }
+
+ /* now the new frame is always in the range of the reordering */
+ /* buffer window */
+ index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
+ % tid_agg_rx->buf_size;
+ /* check if we already stored this frame */
+ if (tid_agg_rx->reorder_buf[index]) {
+ dev_kfree_skb(skb);
+ return 1;
+ }
+
+ /* if arrived mpdu is in the right order and nothing else stored */
+ /* release it immediately */
+ if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
+ tid_agg_rx->stored_mpdu_num == 0) {
+ tid_agg_rx->head_seq_num =
+ seq_inc(tid_agg_rx->head_seq_num);
+ return 0;
+ }
+
+ /* put the frame in the reordering buffer */
+ tid_agg_rx->reorder_buf[index] = skb;
+ tid_agg_rx->stored_mpdu_num++;
+ /* release the buffer until next missing frame */
+ index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
+ % tid_agg_rx->buf_size;
+ while (tid_agg_rx->reorder_buf[index]) {
+ /* release the reordered frame back to stack */
+ memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
+ sizeof(status));
+ pkt_load = ieee80211_rx_load_stats(local,
+ tid_agg_rx->reorder_buf[index],
+ &status);
+ __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
+ &status, pkt_load);
+ tid_agg_rx->stored_mpdu_num--;
+ tid_agg_rx->reorder_buf[index] = NULL;
+ tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
+ index = seq_sub(tid_agg_rx->head_seq_num,
+ tid_agg_rx->ssn) % tid_agg_rx->buf_size;
+ }
+ return 1;
+}
+
+u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
+ struct sk_buff *skb)
+{
+ struct ieee80211_hw *hw = &local->hw;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct sta_info *sta;
+ struct tid_ampdu_rx *tid_agg_rx;
+ u16 fc, sc;
+ u16 mpdu_seq_num;
+ u8 ret = 0, *qc;
+ int tid;
+
+ sta = sta_info_get(local, hdr->addr2);
+ if (!sta)
+ return ret;
+
+ fc = le16_to_cpu(hdr->frame_control);
+
+ /* filter the QoS data rx stream according to
+ * STA/TID and check if this STA/TID is on aggregation */
+ if (!WLAN_FC_IS_QOS_DATA(fc))
+ goto end_reorder;
+
+ qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN;
+ tid = qc[0] & QOS_CONTROL_TID_MASK;
+ tid_agg_rx = &(sta->ampdu_mlme.tid_rx[tid]);
+
+ if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
+ goto end_reorder;
+
+ /* null data frames are excluded */
+ if (unlikely(fc & IEEE80211_STYPE_QOS_NULLFUNC))
+ goto end_reorder;
+
+ /* new un-ordered ampdu frame - process it */
+
+ /* reset session timer */
+ if (tid_agg_rx->timeout) {
+ unsigned long expires =
+ jiffies + (tid_agg_rx->timeout / 1000) * HZ;
+ mod_timer(&tid_agg_rx->session_timer, expires);
+ }
+
+ /* if this mpdu is fragmented - terminate rx aggregation session */
+ sc = le16_to_cpu(hdr->seq_ctrl);
+ if (sc & IEEE80211_SCTL_FRAG) {
+ ieee80211_sta_stop_rx_ba_session(sta->dev, sta->addr,
+ tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
+ ret = 1;
+ goto end_reorder;
+ }
+
+ /* according to mpdu sequence number deal with reordering buffer */
+ mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
+ ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
+ mpdu_seq_num, 0);
+end_reorder:
+ if (sta)
+ sta_info_put(sta);
+ return ret;
+}
+
/*
* This is the receive path handler. It is called by a low level driver when an
* 802.11 MPDU is received from the hardware.
@@ -1779,8 +1958,10 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct
sk_buff *skb,
}
pkt_load = ieee80211_rx_load_stats(local, skb, status);
+ local->channel_use_raw += pkt_load;
- __ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
+ if (!ieee80211_rx_reorder_ampdu(local, skb))
+ __ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
rcu_read_unlock();
}
-
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