mac80211: clarify TDLS Tx handling

Rename the flags used in the Tx path and add an explanation for the
reasons to drop, send directly or through the AP.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 17 insertions, 16 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index f6018178f33c..865bdaf06ff1 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1811,7 +1811,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
         int nh_pos, h_pos;
         struct sta_info *sta = NULL;
         bool wme_sta = false, authorized = false, tdls_auth = false;
-        bool tdls_direct = false;
+        bool tdls_peer = false, tdls_setup_frame = false;
         bool multicast;
         u32 info_flags = 0;
         u16 info_id = 0;
@@ -1953,34 +1953,35 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 #endif
         case NL80211_IFTYPE_STATION:
                 if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
-                        bool tdls_peer = false;
-
                         sta = sta_info_get(sdata, skb->data);
                         if (sta) {
                                 authorized = test_sta_flag(sta,
                                                         WLAN_STA_AUTHORIZED);
                                 wme_sta = test_sta_flag(sta, WLAN_STA_WME);
                                 tdls_peer = test_sta_flag(sta,
-                                                         WLAN_STA_TDLS_PEER);
+                                                          WLAN_STA_TDLS_PEER);
                                 tdls_auth = test_sta_flag(sta,
                                                 WLAN_STA_TDLS_PEER_AUTH);
                         }
 
-                        /*
-                         * If the TDLS link is enabled, send everything
-                         * directly. Otherwise, allow TDLS setup frames
-                         * to be transmitted indirectly.
-                         */
-                        tdls_direct = tdls_peer && (tdls_auth ||
-                                 !(ethertype == ETH_P_TDLS && skb->len > 14 &&
-                                   skb->data[14] == WLAN_TDLS_SNAP_RFTYPE));
+                        if (tdls_peer)
+                                tdls_setup_frame =
+                                        ethertype == ETH_P_TDLS &&
+                                        skb->len > 14 &&
+                                        skb->data[14] == WLAN_TDLS_SNAP_RFTYPE;
                 }
 
-                if (tdls_direct) {
-                        /* link during setup - throw out frames to peer */
-                        if (!tdls_auth)
-                                goto fail_rcu;
+                /*
+                 * TDLS link during setup - throw out frames to peer. We allow
+                 * TDLS-setup frames to unauthorized peers for the special case
+                 * of a link teardown after a TDLS sta is removed due to being
+                 * unreachable.
+                 */
+                if (tdls_peer && !tdls_auth && !tdls_setup_frame)
+                        goto fail_rcu;
 
+                /* send direct packets to authorized TDLS peers */
+                if (tdls_peer && tdls_auth) {
                         /* DA SA BSSID */
                         memcpy(hdr.addr1, skb->data, ETH_ALEN);
                         memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);