CVSROOT: /cvs
Module name: src
Changes by: s...@cvs.openbsd.org 2022/01/12 01:29:27
Modified files:
sys/net80211 : ieee80211_input.c ieee80211_node.c
ieee80211_node.h
Log message:
Remove ieee80211_find_node_for_beacon().
The original purpose of ieee80211_find_node_for_beacon() was to avoid
storing duplicate nodes with the same source MAC address in a hash table.
Later on, our node table data structure was changed from a hash table
to an RB tree. The RB tree can only store a single node per MAC address.
However, find_node_for_beacon() was kept regardless, now documented to
serve a different purpose.
Its new purpose is to tell apart different nodes which happen to use
the same MAC address and hence cannot both be stored in the RB tree.
The idea is to filter such duplicate nodes out during a scan. But colliding
nodes are told apart by RSSI and channel, and either may change over time.
So this does not really prevent duplicate MAC addresses from causing issues.
The code which decides which node is "better" can erroneously match an
AP against itself, in case the AP uses a hidden SSID. This caused
workarounds for hidden SSID to pile up over time.
Just a bit further down, the code looks up the same node again and
performs all of the intended node state updates. Simply skipping the
ieee80211_find_node_for_beacon() check makes such state updates work.
ok tobhe@
