mac80211: fix virtual interfaces vs. injection

Currently, virtual interface pointers passed to drivers might be
from monitor interfaces and as such completely uninitialised
because we do not tell the driver about monitor interfaces when
those are created. Instead of passing them, we should therefore
indicate to the driver that there is no information; do that by
passing a NULL value and adjust drivers to cope with it.

As a result, some mac80211 API functions also need to cope with
a NULL vif pointer so drivers can still call them unconditionally.

Also, when injecting frames we really don't want to pass NULL all
the time, if we know we are the source address of a frame and have
a local interface for that address, we can to use that interface.
This also helps with processing the frame correctly for that
interface which will help the 802.11w implementation. It's not
entirely correct for VLANs or WDS interfaces because there the MAC
address isn't unique, but it's already a lot better than what we
do now.

Finally, when injecting without a matching local interface, don't
assign sequence numbers at all.

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

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index a5e965068c83..b7f4fe8fba6e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -155,7 +155,6 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
 {
         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
-        struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif);
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
         struct ieee80211_rate *rate =
             ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
@@ -278,16 +277,22 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
          * sequence counter given by mac80211.
          */
         if (tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
-                spin_lock_irqsave(&intf->seqlock, irqflags);
+                if (likely(tx_info->control.vif)) {
+                        struct rt2x00_intf *intf;
 
-                if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
-                        intf->seqno += 0x10;
-                hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
-                hdr->seq_ctrl |= cpu_to_le16(intf->seqno);
+                        intf = vif_to_intf(tx_info->control.vif);
 
-                spin_unlock_irqrestore(&intf->seqlock, irqflags);
+                        spin_lock_irqsave(&intf->seqlock, irqflags);
 
-                __set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
+                        if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
+                                intf->seqno += 0x10;
+                        hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
+                        hdr->seq_ctrl |= cpu_to_le16(intf->seqno);
+
+                        spin_unlock_irqrestore(&intf->seqlock, irqflags);
+
+                        __set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
+                }
         }
 
         /*