1. 01 Apr, 2015 1 commit
    • Johannes Berg's avatar
      mac80211: use rhashtable for station table · 7bedd0cf
      Johannes Berg authored
      We currently have a hand-rolled table with 256 entries and are
      using the last byte of the MAC address as the hash. This hash
      is obviously very fast, but collisions are easily created and
      we waste a lot of space in the common case of just connecting
      as a client to an AP where we just have a single station. The
      other common case of an AP is also suboptimal due to the size
      of the hash table and the ease of causing collisions.
      
      Convert all of this to use rhashtable with jhash, which gives
      us the advantage of a far better hash function (with random
      perturbation to avoid hash collision attacks) and of course
      that the hash table grows and shrinks dynamically with chain
      length, improving both cases above.
      
      Use a specialised hash function (using jhash, but with fixed
      length) to achieve better compiler optimisation as suggested
      by Sergey Ryazanov.
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      7bedd0cf
  2. 31 Mar, 2015 39 commits