[PATCH] mac80211: aggregation: Convert timers to use timer_setup()

From: Kees Cook
Date: Tue Oct 17 2017 - 16:25:55 EST

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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@xxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
Resend, with linux-wireless in Cc (no idea how it got missed before)
---
net/mac80211/agg-rx.c | 41 +++++++++++++++++------------------------
net/mac80211/agg-tx.c | 42 ++++++++++++++++--------------------------
net/mac80211/sta_info.c | 8 --------
net/mac80211/sta_info.h | 12 ++++++++++--
4 files changed, 43 insertions(+), 60 deletions(-)

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 88cc1ae935ea..63aba6dbc92a 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;
+ u16 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 */
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index bef516ec47f9..dedbb1fb10e7 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -422,15 +422,12 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
* add Block Ack response will arrive from the recipient.
* If this timer expires sta_addba_resp_timer_expired will be executed.
*/
-static void sta_addba_resp_timer_expired(unsigned long data)
+static void sta_addba_resp_timer_expired(struct timer_list *t)
{
- /* not an elegant detour, but there is no choice as the timer passes
- * only one argument, and both sta_info and TID are needed, so init
- * flow in sta_info_create gives the TID as data, while the timer_to_id
- * array gives the sta through container_of */
- u16 tid = *(u8 *)data;
- struct sta_info *sta = container_of((void *)data,
- struct sta_info, timer_to_tid[tid]);
+ struct tid_ampdu_tx *tid_tx_timer =
+ from_timer(tid_tx_timer, t, addba_resp_timer);
+ struct sta_info *sta = tid_tx_timer->sta;
+ u16 tid = tid_tx_timer->tid;
struct tid_ampdu_tx *tid_tx;

/* check if the TID waits for addBA response */
@@ -525,21 +522,17 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
* After accepting the AddBA Response we activated a timer,
* resetting it after each frame that we send.
*/
-static void sta_tx_agg_session_timer_expired(unsigned long data)
+static void sta_tx_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_tx *tid_tx_timer =
+ from_timer(tid_tx_timer, t, session_timer);
+ struct sta_info *sta = tid_tx_timer->sta;
+ u16 tid = tid_tx_timer->tid;
struct tid_ampdu_tx *tid_tx;
unsigned long timeout;

rcu_read_lock();
- tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]);
+ tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
rcu_read_unlock();
return;
@@ -555,9 +548,9 @@ static void sta_tx_agg_session_timer_expired(unsigned long data)
rcu_read_unlock();

ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n",
- sta->sta.addr, (u16)*ptid);
+ sta->sta.addr, tid);

- ieee80211_stop_tx_ba_session(&sta->sta, *ptid);
+ ieee80211_stop_tx_ba_session(&sta->sta, tid);
}

int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
@@ -672,14 +665,11 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
tid_tx->timeout = timeout;

/* response timer */
- setup_timer(&tid_tx->addba_resp_timer,
- sta_addba_resp_timer_expired,
- (unsigned long)&sta->timer_to_tid[tid]);
+ timer_setup(&tid_tx->addba_resp_timer, sta_addba_resp_timer_expired, 0);

/* tx timer */
- setup_deferrable_timer(&tid_tx->session_timer,
- sta_tx_agg_session_timer_expired,
- (unsigned long)&sta->timer_to_tid[tid]);
+ timer_setup(&tid_tx->session_timer,
+ sta_tx_agg_session_timer_expired, TIMER_DEFERRABLE);

/* assign a dialog token */
sta->ampdu_mlme.dialog_token_allocator++;
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 877d35796776..b5add1464aeb 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -379,14 +379,6 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
if (sta_prepare_rate_control(local, sta, gfp))
goto free_txq;

- for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
- /*
- * timer_to_tid must be initialized with identity mapping
- * to enable session_timer's data differentiation. See
- * sta_rx_agg_session_timer_expired for usage.
- */
- sta->timer_to_tid[i] = i;
- }
for (i = 0; i < IEEE80211_NUM_ACS; i++) {
skb_queue_head_init(&sta->ps_tx_buf[i]);
skb_queue_head_init(&sta->tx_filtered[i]);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 5c54acd10562..1b9c1e81495d 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -126,6 +126,8 @@ enum ieee80211_agg_stop_reason {
AGG_STOP_DESTROY_STA,
};

+struct sta_info;
+
/**
* struct tid_ampdu_tx - TID aggregation information (Tx).
*
@@ -133,8 +135,10 @@ enum ieee80211_agg_stop_reason {
* @session_timer: check if we keep Tx-ing on the TID (by timeout value)
* @addba_resp_timer: timer for peer's response to addba request
* @pending: pending frames queue -- use sta's spinlock to protect
+ * @sta: station we are attached to
* @dialog_token: dialog token for aggregation session
* @timeout: session timeout value to be filled in ADDBA requests
+ * @tid: index in station tid list
* @state: session state (see above)
* @last_tx: jiffies of last tx activity
* @stop_initiator: initiator of a session stop
@@ -158,9 +162,11 @@ struct tid_ampdu_tx {
struct timer_list session_timer;
struct timer_list addba_resp_timer;
struct sk_buff_head pending;
+ struct sta_info *sta;
unsigned long state;
unsigned long last_tx;
u16 timeout;
+ u16 tid;
u8 dialog_token;
u8 stop_initiator;
bool tx_stop;
@@ -181,12 +187,14 @@ struct tid_ampdu_tx {
* @reorder_time: jiffies when skb was added
* @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
* @reorder_timer: releases expired frames from the reorder buffer.
+ * @sta: station we are attached to
* @last_rx: jiffies of last rx activity
* @head_seq_num: head sequence number in reordering buffer.
* @stored_mpdu_num: number of MPDUs in reordering buffer
* @ssn: Starting Sequence Number expected to be aggregated.
* @buf_size: buffer size for incoming A-MPDUs
* @timeout: reset timer value (in TUs).
+ * @tid: index in station tid list
* @rcu_head: RCU head used for freeing this struct
* @reorder_lock: serializes access to reorder buffer, see below.
* @auto_seq: used for offloaded BA sessions to automatically pick head_seq_and
@@ -208,6 +216,7 @@ struct tid_ampdu_rx {
u64 reorder_buf_filtered;
struct sk_buff_head *reorder_buf;
unsigned long *reorder_time;
+ struct sta_info *sta;
struct timer_list session_timer;
struct timer_list reorder_timer;
unsigned long last_rx;
@@ -216,6 +225,7 @@ struct tid_ampdu_rx {
u16 ssn;
u16 buf_size;
u16 timeout;
+ u16 tid;
u8 auto_seq:1,
removed:1,
started:1;
@@ -447,7 +457,6 @@ struct ieee80211_sta_rx_stats {
* plus one for non-QoS frames)
* @tid_seq: per-TID sequence numbers for sending to this STA
* @ampdu_mlme: A-MPDU state machine state
- * @timer_to_tid: identity mapping to ID timers
* @mesh: mesh STA information
* @debugfs_dir: debug filesystem directory dentry
* @dead: set to true when sta is unlinked
@@ -554,7 +563,6 @@ struct sta_info {
* Aggregation information, locked with lock.
*/
struct sta_ampdu_mlme ampdu_mlme;
- u8 timer_to_tid[IEEE80211_NUM_TIDS];

#ifdef CONFIG_MAC80211_DEBUGFS
struct dentry *debugfs_dir;
--
2.7.4

--
Kees Cook
Pixel Security

Next message: Jon Mason: "Re: [PATCH] NTB: ntb_hw_switchtec: Fix peer BAR bug in switchtec_ntb_init_shared_mw"
Previous message: SF Markus Elfring: "Re: char/tpm: Improve a size determination in nine functions"
Next in thread: Johannes Berg: "Re: [PATCH] mac80211: aggregation: Convert timers to use timer_setup()"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]