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>

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index f601817..865bdaf 100644 (file)
--- 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);