struct ieee80211_tx_info {
  u32 flags;
  u8 band;
  u8 antenna_sel_tx;
  u8 pad[2];
  union {unnamed_union};
};  
 
flags
band
antenna_sel_tx
pad[2]
{unnamed_union}
This structure is placed in skb->cb for three uses: (1) mac80211 TX control - mac80211 tells the driver what to do (2) driver internal use (if applicable) (3) TX status information - driver tells mac80211 what happened
The TX control's sta pointer is only valid during the ->tx call, it may be NULL.
Johannes Berg <johannes@sipsolutions.net>