• Johannes Berg's avatar
    nl80211: fix scheduled scan RSSI matchset attribute confusion · ea73cbce
    Johannes Berg authored
    The scheduled scan matchsets were intended to be a list of filters,
    with the found BSS having to pass at least one of them to be passed
    to the host. When the RSSI attribute was added, however, this was
    broken and currently wpa_supplicant adds that attribute in its own
    matchset; however, it doesn't intend that to mean that anything
    that passes the RSSI filter should be passed to the host, instead
    it wants it to mean that everything needs to also have higher RSSI.
    This is semantically problematic because we have a list of filters
    like [ SSID1, SSID2, SSID3, RSSI ] with no real indication which
    one should be OR'ed and which one AND'ed.
    To fix this, move the RSSI filter attribute into each matchset. As
    we need to stay backward compatible, treat a matchset with only the
    RSSI attribute as a "default RSSI filter" for all other matchsets,
    but only if there are other matchsets (an RSSI-only matchset by
    itself is still desirable.)
    To make driver implementation easier, keep a global min_rssi_thold
    for the entire request as well. The only affected driver is ath6kl.
    I found this when I looked into the code after Raja Mani submitted
    a patch fixing the n_match_sets calculation to disregard the RSSI,
    but that patch didn't address the semantic issue.
    Reported-by: default avatarRaja Mani <rmani@qti.qualcomm.com>
    Acked-by: default avatarLuciano Coelho <luciano.coelho@intel.com>
    Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
cfg80211.h 164 KB