The reorder buffer handling is written in a quite
peculiar style (especially comments) and also has
a quirk where it invokes the entire reorder code
in ieee80211_sta_manage_reorder_buf() for just a
handful of lines in it with a special argument.
Split out ieee80211_release_reorder_frames which
can then be invoked from BAR handling and other
reordering code, clean up code and comments and
remove function arguments that are now unused from
ieee80211_sta_manage_reorder_buf().
Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
---
net/mac80211/rx.c | 162 +++++++++++++++++++++++++++---------------------------
1 file changed, 81 insertions(+), 81 deletions(-)
--- wireless-testing.orig/net/mac80211/rx.c 2009-11-16 11:40:20.000000000 +0100
+++ wireless-testing/net/mac80211/rx.c 2009-11-16 11:48:36.000000000 +0100
@@ -27,11 +27,10 @@
#include "tkip.h"
#include "wme.h"
-static 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);
+static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
+ struct tid_ampdu_rx *tid_agg_rx,
+ u16 head_seq_num);
+
/*
* monitor mode reception
*
@@ -1592,11 +1591,11 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_
if (ieee80211_is_back_req(bar->frame_control)) {
if (!rx->sta)
- return RX_CONTINUE;
+ return RX_DROP_MONITOR;
tid = le16_to_cpu(bar->control) >> 12;
if (rx->sta->ampdu_mlme.tid_state_rx[tid]
!= HT_AGG_STATE_OPERATIONAL)
- return RX_CONTINUE;
+ return RX_DROP_MONITOR;
tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
@@ -1606,13 +1605,10 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_
mod_timer(&tid_agg_rx->session_timer,
TU_TO_EXP_TIME(tid_agg_rx->timeout));
- /* manage reordering buffer according to requested */
- /* sequence number */
- rcu_read_lock();
- ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
- start_seq_num, 1);
- rcu_read_unlock();
- return RX_DROP_UNUSABLE;
+ /* release stored frames up to start of BAR */
+ ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
+ kfree_skb(skb);
+ return RX_QUEUED;
}
return RX_CONTINUE;
@@ -2223,6 +2219,18 @@ no_frame:
tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
}
+static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
+ struct tid_ampdu_rx *tid_agg_rx,
+ u16 head_seq_num)
+{
+ int index;
+
+ 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;
+ ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
+ }
+}
/*
* Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
@@ -2234,15 +2242,17 @@ no_frame:
#define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
/*
- * As it function blongs to Rx path it must be called with
- * the proper rcu_read_lock protection for its flow.
+ * As this function belongs to the RX path it must be under
+ * rcu_read_lock protection. It returns false if the frame
+ * can be processed immediately, true if it was consumed.
*/
-static 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)
+static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
+ struct tid_ampdu_rx *tid_agg_rx,
+ struct sk_buff *skb)
{
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ u16 sc = le16_to_cpu(hdr->seq_ctrl);
+ u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
u16 head_seq_num, buf_size;
int index;
@@ -2252,47 +2262,37 @@ static u8 ieee80211_sta_manage_reorder_b
/* frame with out of date sequence number */
if (seq_less(mpdu_seq_num, head_seq_num)) {
dev_kfree_skb(skb);
- return 1;
+ return true;
}
- /* 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));
+ /*
+ * If frame the sequence number exceeds our buffering window
+ * size release some previous frames to make room for this one.
+ */
+ if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
+ 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;
- ieee80211_release_reorder_frame(hw, tid_agg_rx,
- index);
- }
- if (bar_req)
- return 1;
+ ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
}
- /* 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;
+ /* Now the new frame is always in the range of the reordering buffer */
+
+ 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;
+ return true;
}
- /* if arrived mpdu is in the right order and nothing else stored */
- /* release it immediately */
+ /*
+ * If the current MPDU is in the right order and nothing else
+ * is stored we can process it directly, no need to buffer it.
+ */
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;
+ tid_agg_rx->stored_mpdu_num == 0) {
+ tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
+ return false;
}
/* put the frame in the reordering buffer */
@@ -2300,8 +2300,8 @@ static u8 ieee80211_sta_manage_reorder_b
tid_agg_rx->reorder_time[index] = jiffies;
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;
+ 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] &&
tid_agg_rx->stored_mpdu_num > 1) {
/*
@@ -2312,12 +2312,12 @@ static u8 ieee80211_sta_manage_reorder_b
int skipped = 1;
for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
j = (j + 1) % tid_agg_rx->buf_size) {
- if (tid_agg_rx->reorder_buf[j] == NULL) {
+ if (!tid_agg_rx->reorder_buf[j]) {
skipped++;
continue;
}
if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
- HZ / 10))
+ HT_RX_REORDER_BUF_TIMEOUT))
break;
#ifdef CONFIG_MAC80211_HT_DEBUG
@@ -2333,51 +2333,56 @@ static u8 ieee80211_sta_manage_reorder_b
* Increment the head seq# also for the skipped slots.
*/
tid_agg_rx->head_seq_num =
- (tid_agg_rx->head_seq_num + skipped) &
- SEQ_MASK;
+ (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
skipped = 0;
}
} else while (tid_agg_rx->reorder_buf[index]) {
ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
- index = seq_sub(tid_agg_rx->head_seq_num,
- tid_agg_rx->ssn) % tid_agg_rx->buf_size;
+ index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
+ tid_agg_rx->buf_size;
}
- return 1;
+
+ return true;
}
-static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
- struct sk_buff *skb)
+/*
+ * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
+ * true if the MPDU was buffered, false if it should be processed.
+ */
+static bool 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 sc;
- u16 mpdu_seq_num;
- u8 ret = 0;
int tid;
+ if (!ieee80211_is_data_qos(hdr->frame_control))
+ return false;
+
+ /*
+ * filter the QoS data rx stream according to
+ * STA/TID and check if this STA/TID is on aggregation
+ */
+
sta = sta_info_get(local, hdr->addr2);
if (!sta)
- return ret;
-
- /* filter the QoS data rx stream according to
- * STA/TID and check if this STA/TID is on aggregation */
- if (!ieee80211_is_data_qos(hdr->frame_control))
- goto end_reorder;
+ return false;
tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
- goto end_reorder;
+ return false;
tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
/* qos null data frames are excluded */
if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
- goto end_reorder;
+ return false;
- /* new un-ordered ampdu frame - process it */
+ /* new, potentially un-ordered, ampdu frame - process it */
/* reset session timer */
if (tid_agg_rx->timeout)
@@ -2389,16 +2394,11 @@ static u8 ieee80211_rx_reorder_ampdu(str
if (sc & IEEE80211_SCTL_FRAG) {
ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
- ret = 1;
- goto end_reorder;
+ dev_kfree_skb(skb);
+ return true;
}
- /* 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:
- return ret;
+ return ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb);
}
/*
--
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