mac80211: fix TX sequence numbers

This patch makes mac80211 assign proper sequence numbers to
QoS-data frames. It also removes the old sequence number code
because we noticed that only the driver or hardware can assign
sequence numbers to non-QoS-data and especially management
frames in a race-free manner because beacons aren't passed
through mac80211's TX path.

This patch also adds temporary code to the rt2x00 drivers to
not break them completely, that code will have to be reworked
for proper sequence numbers on beacons.

It also moves sequence number assignment down in the TX path
so no sequence numbers are assigned to frames that are dropped.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 15 insertions, 0 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index f0d7e083d8f8..9fab0df18c3c 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -364,6 +364,8 @@ struct rt2x00_intf {
 #define DELAYED_UPDATE_BEACON           0x00000001
 #define DELAYED_CONFIG_ERP              0x00000002
 #define DELAYED_LED_ASSOC               0x00000004
+
+        u16 seqno;
 };
 
 static inline struct rt2x00_intf* vif_to_intf(struct ieee80211_vif *vif)
diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
index 16b72d9ca1c3..77af1df5d899 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -96,6 +96,7 @@ int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
         struct ieee80211_hdr *ieee80211hdr = (struct ieee80211_hdr *)skb->data;
         enum data_queue_qid qid = skb_get_queue_mapping(skb);
+        struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif);
         struct data_queue *queue;
         u16 frame_control;
 
@@ -151,6 +152,18 @@ int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
                 }
         }
 
+        /*
+         * XXX: This is as wrong as the old mac80211 code was,
+         *      due to beacons not getting sequence numbers assigned
+         *      properly.
+         */
+        if (tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
+                if (tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT)
+                        intf->seqno += 0x10;
+                ieee80211hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
+                ieee80211hdr->seq_ctrl |= cpu_to_le16(intf->seqno);
+        }
+
         if (rt2x00queue_write_tx_frame(queue, skb)) {
                 ieee80211_stop_queue(rt2x00dev->hw, qid);
                 return NETDEV_TX_BUSY;