| From b478e06a16a8baa00c5ecc87c1d636981f2206d5 Mon Sep 17 00:00:00 2001 |
| From: Johannes Berg <johannes.berg@intel.com> |
| Date: Tue, 29 Oct 2019 10:25:25 +0100 |
| Subject: [PATCH] mac80211: sta: randomize BA session dialog token allocator |
| |
| We currently always start the dialog token generator at zero, |
| so the first dialog token we use is always 1. This would be |
| OK if we had a perfect guarantee that we always do a proper |
| deauth/re-auth handshake, but in IBSS mode this doesn't always |
| happen properly. |
| |
| To make problems with block ack (aggregation) sessions getting |
| stuck less likely, randomize the dialog token so if we start a |
| new session but the peer still has old state for us, it can |
| better detect this. |
| |
| This is really just a workaround to make things a bit more |
| robust than they are now - a better fix would be to do a full |
| authentication handshake in IBSS mode upon having discovered a |
| new station, and on the receiver resetting the state (removing |
| and re-adding the station) on receiving the authentication |
| packet. |
| |
| Signed-off-by: Johannes Berg <johannes.berg@intel.com> |
| --- |
| net/mac80211/sta_info.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| --- a/net/mac80211/sta_info.c |
| +++ b/net/mac80211/sta_info.c |
| @@ -561,6 +561,11 @@ __sta_info_alloc(struct ieee80211_sub_if |
| INIT_WORK(&sta->drv_deliver_wk, sta_deliver_ps_frames); |
| INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work); |
| mutex_init(&sta->ampdu_mlme.mtx); |
| +#if LINUX_VERSION_IS_LESS(6,2,0) |
| + sta->ampdu_mlme.dialog_token_allocator = prandom_u32_max(U8_MAX); |
| +#else |
| + sta->ampdu_mlme.dialog_token_allocator = get_random_u32_below(U8_MAX); |
| +#endif |
| #ifdef CPTCFG_MAC80211_MESH |
| if (ieee80211_vif_is_mesh(&sdata->vif)) { |
| sta->mesh = kzalloc(sizeof(*sta->mesh), gfp); |