IEEE80211_GET_BUFFER

Section: Advanced driver interface (9)
Updated: February 2011
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NAME

ieee80211_get_buffered_bc - accessing buffered broadcast and multicast frames

SYNOPSIS

struct sk_buff * ieee80211_get_buffered_bc(struct ieee80211_hw * hw, struct ieee80211_vif * vif);

ARGUMENTS

: pointer as obtained from ieee80211_alloc_hw.

vif

: struct ieee80211_vif pointer from the add_interface callback.

DESCRIPTION

Function for accessing buffered broadcast and multicast frames. If hardware/firmware does not implement buffering of broadcast/multicast frames when power saving is used, 802.11 code buffers them in the host memory. The low-level driver uses this function to fetch next buffered frame. In most cases, this is used when generating beacon frame. This function returns a pointer to the next buffered skb or NULL if no more buffered frames are available.

NOTE

buffered frames are returned only after DTIM beacon frame was generated with ieee80211_beacon_get and the low-level driver must thus call ieee80211_beacon_get first. ieee80211_get_buffered_bc returns NULL if the previous generated beacon was not DTIM, so the low-level driver does not need to check for DTIM beacons separately and should be able to use common code for all beacons.

AUTHOR

Johannes Berg <johannes@sipsolutions.net>

: Author.