• Daniel Yingqiang Ma's avatar
    ath9k: Group Key fix for VAPs · 03ceedea
    Daniel Yingqiang Ma authored
    When I set up multiple VAPs with ath9k, I encountered an issue that
    the traffic may be lost after a while.
    
    The detailed phenomenon is
    1. After a while the clients connected to one of these VAPs will get
    into a state that no broadcast/multicast packets can be transfered
    successfully while the unicast packets can be transfered normally.
    2. Minutes latter the unitcast packets transfer will fail as well,
    because the ARP entry is expired and it can't be freshed due to the
    broadcast trouble.
    
    It's caused by the group key overwritten and someone discussed this
    issue in ath9k-devel maillist before, but haven't work out a fix yet.
    
    I referred the method in madwifi, and made a patch for ath9k.
    The method is to set the high bit of the sender(AP)'s address, and
    associated that mac and the group key. It requires the hardware
    supports multicast frame key search. It seems true for AR9160.
    
    Not sure whether it's the correct way to fix this issue. But it seems
    to work in my test. The patch is attached, feel free to revise it.
    Signed-off-by: default avatarDaniel Yingqiang ma <yma.cool@gmail.com>
    Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
    03ceedea
key.c 14.9 KB