Commit 31104891 authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: allow driver to prevent two stations w/ same address



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: default avatarJohannes Berg <johannes.berg@intel.com>
parent d9d3ac7a
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+6 −0
Original line number Diff line number Diff line
@@ -1901,6 +1901,11 @@ 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 {
@@ -1936,6 +1941,7 @@ 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
+1 −0
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ static const char *hw_flag_names[NUM_IEEE80211_HW_FLAGS + 1] = {
	FLAG(TDLS_WIDER_BW),
	FLAG(SUPPORTS_AMSDU_IN_AMPDU),
	FLAG(BEACON_TX_STATUS),
	FLAG(NEEDS_UNIQUE_STA_ADDR),

	/* keep last for the build bug below */
	(void *)0x1
+16 −2
Original line number Diff line number Diff line
@@ -435,6 +435,19 @@ static int sta_info_insert_check(struct sta_info *sta)
		    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;
}

@@ -554,14 +567,15 @@ int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU)

	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;