xref: /dflybsd-src/share/man/man9/ieee80211_bmiss.9 (revision e4c06619483849b6d1d179ae56da763ed720062d)
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2705ac2d0dSSascha Wildner.\"
2805ac2d0dSSascha Wildner.Dd April 28, 2010
2905ac2d0dSSascha Wildner.Dt IEEE80211_BMISS 9
3005ac2d0dSSascha Wildner.Os
3105ac2d0dSSascha Wildner.Sh NAME
3205ac2d0dSSascha Wildner.Nm ieee80211_bmiss
3305ac2d0dSSascha Wildner.Nd 802.11 beacon miss support
3405ac2d0dSSascha Wildner.Sh SYNOPSIS
357d9c9280SSascha Wildner.In net/if.h
367d9c9280SSascha Wildner.In net/if_media.h
37737edb20SSascha Wildner.In netproto/802_11/ieee80211_var.h
3805ac2d0dSSascha Wildner.Pp
3905ac2d0dSSascha Wildner.Ft void
4005ac2d0dSSascha Wildner.Fn ieee80211_beacon_miss "struct ieee80211com *"
4105ac2d0dSSascha Wildner.Sh DESCRIPTION
4205ac2d0dSSascha WildnerThe
4305ac2d0dSSascha Wildner.Nm net80211
4405ac2d0dSSascha Wildnersoftware layer provides a support framework for drivers that includes
4505ac2d0dSSascha Wildnerhandling beacon miss events in station mode.
4605ac2d0dSSascha WildnerDrivers can dispatch beacon miss events that are recognized in hardware or
4705ac2d0dSSascha Wildner.Nm net80211
4805ac2d0dSSascha Wildnercan detect beacon miss if the driver dispatches received beacon frames
4905ac2d0dSSascha Wildnerthrough the normal receive path.
5005ac2d0dSSascha WildnerSoftware beacon miss support is especially useful when multiple vaps
5105ac2d0dSSascha Wildnerare operating and any hardware beacon miss support is not available
5205ac2d0dSSascha Wildner(e.g. operating as an access point together with one or more station
5305ac2d0dSSascha Wildnermode vaps).
5405ac2d0dSSascha Wildner.Pp
5505ac2d0dSSascha WildnerDrivers should dispatch beacon miss events recognized in the driver with
5605ac2d0dSSascha Wildner.Fn ieee80211_beacon_miss .
5705ac2d0dSSascha WildnerThis causes some number of ProbeRequest frames to be sent to the
5805ac2d0dSSascha Wildneraccess point to check if the association is still alive.
5905ac2d0dSSascha WildnerIf no response is received and roaming mode is set to
6005ac2d0dSSascha Wildner.Dv IEEE80211_ROAMING_AUTO
6105ac2d0dSSascha Wildnerthen
6205ac2d0dSSascha Wildner.Nm net80211
6305ac2d0dSSascha Wildnerwill try to re-associate and if that fails
6405ac2d0dSSascha Wildnertrigger a scan to look for the access point or another suitable AP.
6505ac2d0dSSascha WildnerWhen the
6605ac2d0dSSascha Wildner.Nm net80211
6705ac2d0dSSascha Wildnerstate machine is being operated manually, e.g. by
6805ac2d0dSSascha Wildner.Xr wpa_supplicant 8 ,
6905ac2d0dSSascha Wildnerthen applications are notified of the state change and are responsible
7005ac2d0dSSascha Wildnerfor handling the work of scanning for a new access point.
7105ac2d0dSSascha WildnerThe number of beacon miss events (without a ProbeResponse) is user
7205ac2d0dSSascha Wildnersettable with the
7305ac2d0dSSascha Wildner.Dv IEEE80211_IOC_BMISSTHRESHOLD
7405ac2d0dSSascha Wildnerrequest.
7505ac2d0dSSascha Wildner.Pp
7605ac2d0dSSascha WildnerSoftware beacon miss detection is enabled per-vap by setting the
7705ac2d0dSSascha Wildner.Dv IEEE80211_FEXT_SWBMISS
7805ac2d0dSSascha Wildnerflag.
7905ac2d0dSSascha WildnerTypically this is done when a vap is setup
8005ac2d0dSSascha Wildnerwhen the
8105ac2d0dSSascha Wildner.Dv IEEE80211_CLONE_NOBEACONS
8205ac2d0dSSascha Wildneroption is supplied to the clone operation.
8305ac2d0dSSascha WildnerBut drivers may also force this when they know they need help detecting
8405ac2d0dSSascha Wildnerbeacon miss.
8505ac2d0dSSascha WildnerWhen beacon miss is detected in software the event is dispatched without
8605ac2d0dSSascha Wildnerdriver involvement.
8705ac2d0dSSascha WildnerNote that software beacon miss handling is not limited to station mode;
8805ac2d0dSSascha Wildnerit can be used in any operating mode where beacons from a peer station
8905ac2d0dSSascha Wildnerare received.
9005ac2d0dSSascha Wildner.Sh SEE ALSO
9105ac2d0dSSascha Wildner.Xr wpa_supplicant 8 ,
9205ac2d0dSSascha Wildner.Xr ieee80211 9 ,
9305ac2d0dSSascha Wildner.Xr ieee80211_vap 9
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