mac80211: aggregation: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

This removes the tid mapping array and expands the tid structures to
add a pointer back to the station, along with the tid index itself.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
[switch tid variables to u8, the valid range is 0-15 at most,
 initialize tid_tx->sta/tid properly]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 17 insertions, 24 deletions

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 88cc1ae935ea..d444752dbf40 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -151,21 +151,17 @@ EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
  * After accepting the AddBA Request we activated a timer,
  * resetting it after each frame that arrives from the originator.
  */
-static void sta_rx_agg_session_timer_expired(unsigned long data)
+static void sta_rx_agg_session_timer_expired(struct timer_list *t)
 {
-	/* 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]);
+	struct tid_ampdu_rx *tid_rx_timer =
+		from_timer(tid_rx_timer, t, session_timer);
+	struct sta_info *sta = tid_rx_timer->sta;
+	u8 tid = tid_rx_timer->tid;
 	struct tid_ampdu_rx *tid_rx;
 	unsigned long timeout;
 
 	rcu_read_lock();
-	tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
+	tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 	if (!tid_rx) {
 		rcu_read_unlock();
 		return;
@@ -180,21 +176,18 @@ static void sta_rx_agg_session_timer_expired(unsigned long data)
 	rcu_read_unlock();
 
 	ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
-	       sta->sta.addr, (u16)*ptid);
+	       sta->sta.addr, tid);
 
-	set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
+	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
 }
 
-static void sta_rx_agg_reorder_timer_expired(unsigned long data)
+static void sta_rx_agg_reorder_timer_expired(struct timer_list *t)
 {
-	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]);
+	struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, reorder_timer);
 
 	rcu_read_lock();
-	ieee80211_release_reorder_timeout(sta, *ptid);
+	ieee80211_release_reorder_timeout(tid_rx->sta, tid_rx->tid);
 	rcu_read_unlock();
 }
 
@@ -356,14 +349,12 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
 	spin_lock_init(&tid_agg_rx->reorder_lock);
 
 	/* rx timer */
-	setup_deferrable_timer(&tid_agg_rx->session_timer,
-			       sta_rx_agg_session_timer_expired,
-			       (unsigned long)&sta->timer_to_tid[tid]);
+	timer_setup(&tid_agg_rx->session_timer,
+		    sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
 
 	/* rx reorder timer */
-	setup_timer(&tid_agg_rx->reorder_timer,
-		    sta_rx_agg_reorder_timer_expired,
-		    (unsigned long)&sta->timer_to_tid[tid]);
+	timer_setup(&tid_agg_rx->reorder_timer,
+		    sta_rx_agg_reorder_timer_expired, 0);
 
 	/* prepare reordering buffer */
 	tid_agg_rx->reorder_buf =
@@ -399,6 +390,8 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
 	tid_agg_rx->auto_seq = auto_seq;
 	tid_agg_rx->started = false;
 	tid_agg_rx->reorder_buf_filtered = 0;
+	tid_agg_rx->tid = tid;
+	tid_agg_rx->sta = sta;
 	status = WLAN_STATUS_SUCCESS;
 
 	/* activate it for RX */