Do not allocate more channel contexts than a
driver is capable for currently matching interface
combination.
This allows the ieee80211_vif_reserve_chanctx() to
act as a guard against breaking interface
combinations.
Signed-off-by: Michal Kazior <michal.kazior@xxxxxxxxx>
---
net/mac80211/chan.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index ee77795..2bf2d01 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -9,6 +9,25 @@
#include "ieee80211_i.h"
#include "driver-ops.h"
+static int ieee80211_num_chanctx(struct ieee80211_local *local)
+{
+ struct ieee80211_chanctx *ctx;
+ int num = 0;
+
+ lockdep_assert_held(&local->chanctx_mtx);
+
+ list_for_each_entry(ctx, &local->chanctx_list, list)
+ num++;
+
+ return num;
+}
+
+static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
+{
+ lockdep_assert_held(&local->chanctx_mtx);
+ return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
+}
+
static enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
{
switch (sta->bandwidth) {
@@ -745,13 +764,16 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
* context, reserve our current context
*/
new_ctx = curr_ctx;
- } else {
+ } else if (ieee80211_can_create_new_chanctx(local)) {
/* create a new context and reserve it */
new_ctx = ieee80211_new_chanctx(local, chandef, mode);
if (IS_ERR(new_ctx)) {
ret = PTR_ERR(new_ctx);
goto out;
}
+ } else {
+ ret = -EBUSY;
+ goto out;
}
}
--
1.8.5.3
--
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