1. 07 May, 2010 1 commit
    • Johannes Berg's avatar
      cfg80211/mac80211: better channel handling · f444de05
      Johannes Berg authored
      
      
      Currently (all tested with hwsim) you can do stupid
      things like setting up an AP on a certain channel,
      then adding another virtual interface and making
      that associate on another channel -- this will make
      the beaconing to move channel but obviously without
      the necessary IEs data update.
      
      In order to improve this situation, first make the
      configuration APIs (cfg80211 and nl80211) aware of
      multi-channel operation -- we'll eventually need
      that in the future anyway. There's one userland API
      change and one API addition. The API change is that
      now SET_WIPHY must be called with virtual interface
      index rather than only wiphy index in order to take
      effect for that interface -- luckily all current
      users (hostapd) do that. For monitor interfaces, the
      old setting is preserved, but monitors are always
      slaved to other devices anyway so no guarantees.
      
      The second userland API change is the introduction
      of a per virtual interface SET_CHANNEL command, that
      hostapd should use going forward to make it easier
      to understand what's going on (it can automatically
      detect a kernel with this command).
      
      Other than mac80211, no existing cfg80211 drivers
      are affected by this change because they only allow
      a single virtual interface.
      
      mac80211, however, now needs to be aware that the
      channel settings are per interface now, and needs
      to disallow (for now) real multi-channel operation,
      which is another important part of this patch.
      
      One of the immediate benefits is that you can now
      start hostapd to operate on a hardware that already
      has a connection on another virtual interface, as
      long as you specify the same channel.
      
      Note that two things are left unhandled (this is an
      improvement -- not a complete fix):
      
       * different HT/no-HT modes
      
         currently you could start an HT AP and then
         connect to a non-HT network on the same channel
         which would configure the hardware for no HT;
         that can be fixed fairly easily
      
       * CSA
      
         An AP we're connected to on a virtual interface
         might indicate switching channels, and in that
         case we would follow it, regardless of how many
         other interfaces are operating; this requires
         more effort to fix but is pretty rare after all
      Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
      f444de05
  2. 03 May, 2010 1 commit
  3. 19 Apr, 2010 1 commit
  4. 04 Aug, 2009 1 commit
  5. 10 Jul, 2009 3 commits