From: Johannes Berg <[email protected]> commit 3110489117581a980537b6d999a3724214ba772c upstream.
Some devices or drivers cannot deal with having the same station address for different virtual interfaces, say as a client to two virtual AP interfaces. Rather than requiring each driver with a limitation like that to enforce it, add a hardware flag for it. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- include/net/mac80211.h | 6 ++++++ net/mac80211/debugfs.c | 1 + net/mac80211/sta_info.c | 18 ++++++++++++++++-- 3 files changed, 23 insertions(+), 2 deletions(-) --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1915,6 +1915,11 @@ struct ieee80211_txq { * @IEEE80211_HW_BEACON_TX_STATUS: The device/driver provides TX status * for sent beacons. * + * @IEEE80211_HW_NEEDS_UNIQUE_STA_ADDR: Hardware (or driver) requires that each + * station has a unique address, i.e. each station entry can be identified + * by just its MAC address; this prevents, for example, the same station + * from connecting to two virtual AP interfaces at the same time. + * * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays */ enum ieee80211_hw_flags { @@ -1950,6 +1955,7 @@ enum ieee80211_hw_flags { IEEE80211_HW_TDLS_WIDER_BW, IEEE80211_HW_SUPPORTS_AMSDU_IN_AMPDU, IEEE80211_HW_BEACON_TX_STATUS, + IEEE80211_HW_NEEDS_UNIQUE_STA_ADDR, /* keep last, obviously */ NUM_IEEE80211_HW_FLAGS --- a/net/mac80211/debugfs.c +++ b/net/mac80211/debugfs.c @@ -125,6 +125,7 @@ static const char *hw_flag_names[] = { FLAG(TDLS_WIDER_BW), FLAG(SUPPORTS_AMSDU_IN_AMPDU), FLAG(BEACON_TX_STATUS), + FLAG(NEEDS_UNIQUE_STA_ADDR), #undef FLAG }; --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -457,6 +457,19 @@ static int sta_info_insert_check(struct is_multicast_ether_addr(sta->sta.addr))) return -EINVAL; + /* Strictly speaking this isn't necessary as we hold the mutex, but + * the rhashtable code can't really deal with that distinction. We + * do require the mutex for correctness though. + */ + rcu_read_lock(); + lockdep_assert_held(&sdata->local->sta_mtx); + if (ieee80211_hw_check(&sdata->local->hw, NEEDS_UNIQUE_STA_ADDR) && + ieee80211_find_sta_by_ifaddr(&sdata->local->hw, sta->addr, NULL)) { + rcu_read_unlock(); + return -ENOTUNIQ; + } + rcu_read_unlock(); + return 0; } @@ -585,14 +598,15 @@ int sta_info_insert_rcu(struct sta_info might_sleep(); + mutex_lock(&local->sta_mtx); + err = sta_info_insert_check(sta); if (err) { + mutex_unlock(&local->sta_mtx); rcu_read_lock(); goto out_free; } - mutex_lock(&local->sta_mtx); - err = sta_info_insert_finish(sta); if (err) goto out_free;
