Commit c2b90ad8 authored by Michal Kazior's avatar Michal Kazior Committed by Johannes Berg

mac80211: prevent chanctx overcommit

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: default avatarMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 6fa001bc
......@@ -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) {
......@@ -751,13 +770,16 @@ 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;
}
}
......
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