• Nicolas Escande's avatar
    mac80211: fix forwarded mesh frames AC & queue selection · 859ae701
    Nicolas Escande authored
    There are two problems with the current code that have been highlighted
    with the AQL feature that is now enbaled by default.
    
    First problem is in ieee80211_rx_h_mesh_fwding(),
    ieee80211_select_queue_80211() is used on received packets to choose
    the sending AC queue of the forwarding packet although this function
    should only be called on TX packet (it uses ieee80211_tx_info).
    This ends with forwarded mesh packets been sent on unrelated random AC
    queue. To fix that, AC queue can directly be infered from skb->priority
    which has been extracted from QOS info (see ieee80211_parse_qos()).
    
    Second problem is the value of queue_mapping set on forwarded mesh
    frames via skb_set_queue_mapping() is not the AC of the packet but a
    hardware queue index. This may or may not work depending on AC to HW
    queue mapping which is driver specific.
    
    Both of these issues lead to improper AC selection while forwarding
    mesh packets but more importantly due to improper airtime accounting
    (which is done on a per STA, per AC basis) caused traffic stall with
    the introduction of AQL.
    
    Fixes: cf440128 ("mac80211: fix unnecessary frame drops in mesh fwding")
    Fixes: d3c1597b ("mac80211: fix forwarded mesh frame queue mapping")
    Co-developed-by: default avatarRemi Pommarel <repk@triplefau.lt>
    Signed-off-by: default avatarRemi Pommarel <repk@triplefau.lt>
    Signed-off-by: default avatarNicolas Escande <nico.escande@gmail.com>
    Link: https://lore.kernel.org/r/20220214173214.368862-1-nico.escande@gmail.comSigned-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
    859ae701
rx.c 139 KB