mac80211: data path modification for TDLS peers

Mark the STA entries of enabled TDLS peers with a new "peer authorized"
flag.

During link setup, allow special TDLS setup frames through the AP, but
otherwise drop all packets destined to the peer. This is required by the
TDLS (802.11z) specification in order to prevent reordering of MSDUs
between the AP and direct paths.

When setup completes and the peer is authorized, send data directly,
bypassing the AP.

In the Rx path, allow data to be received directly from TDLS peers.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 119a573af14bb3ffedd28f34a543f5ad314ed2e5..bdf9852eec5b33ca64c09a7354d79ada73beef50 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2427,6 +2427,7 @@ fail:
 static int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev,
                               u8 *peer, enum nl80211_tdls_operation oper)
 {
+       struct sta_info *sta;
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
        if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
@@ -2441,6 +2442,15 @@ static int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev,
 
        switch (oper) {
        case NL80211_TDLS_ENABLE_LINK:
+               rcu_read_lock();
+               sta = sta_info_get(sdata, peer);
+               if (!sta) {
+                       rcu_read_unlock();
+                       return -ENOLINK;
+               }
+
+               set_sta_flags(sta, WLAN_STA_TDLS_PEER_AUTH);
+               rcu_read_unlock();
                break;
        case NL80211_TDLS_DISABLE_LINK:
                return sta_info_destroy_addr(sdata, peer);

diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index b6bd4e9d87224c5271fc63e45b714f7e9265cef0..c10e2e8632b5252e1fe312d87bfde4be43dc3157 100644 (file)
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -45,7 +45,9 @@
  *     station in power-save mode, reply when the driver unblocks.
  * @WLAN_STA_PS_DRIVER_BUF: Station has frames pending in driver internal
  *     buffers. Automatically cleared on station wake-up.
- * @WLAN_STA_TDLS_PEER: station is a TDLS peer.
+ * @WLAN_STA_TDLS_PEER: Station is a TDLS peer.
+ * @WLAN_STA_TDLS_PEER_AUTH: This TDLS peer is authorized to send direct
+ *     packets. This means the link is enabled.
  */
 enum ieee80211_sta_info_flags {
        WLAN_STA_AUTH           = 1<<0,
@@ -63,6 +65,7 @@ enum ieee80211_sta_info_flags {
        WLAN_STA_PSPOLL         = 1<<13,
        WLAN_STA_PS_DRIVER_BUF  = 1<<14,
        WLAN_STA_TDLS_PEER      = 1<<15,
+       WLAN_STA_TDLS_PEER_AUTH = 1<<16,
 };
 
 #define STA_TID_NUM 16

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 542272acfc1a4677c08cf2a1f9c6e45ceb7ae5ed..0ca16880bbb4449dc40a1124f45aca3ba9cf259f 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1726,6 +1726,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
        struct sta_info *sta = NULL;
        u32 sta_flags = 0;
        struct sk_buff *tmp_skb;
+       bool tdls_direct = false;
 
        if (unlikely(skb->len < ETH_HLEN)) {
                ret = NETDEV_TX_OK;
@@ -1837,11 +1838,43 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
                break;
 #endif
        case NL80211_IFTYPE_STATION:
-               memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
-               if (sdata->u.mgd.use_4addr &&
-                   cpu_to_be16(ethertype) != sdata->control_port_protocol) {
-                       fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
+               if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
+                       rcu_read_lock();
+                       sta = sta_info_get(sdata, skb->data);
+                       if (sta)
+                               sta_flags = get_sta_flags(sta);
+                       rcu_read_unlock();
+
+                       /*
+                        * If the TDLS link is enabled, send everything
+                        * directly. Otherwise, allow TDLS setup frames
+                        * to be transmitted indirectly.
+                        */
+                       tdls_direct =
+                               (sta_flags & WLAN_STA_TDLS_PEER) &&
+                               ((sta_flags & WLAN_STA_TDLS_PEER_AUTH) ||
+                                !(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 (!(sta_flags & WLAN_STA_TDLS_PEER_AUTH)) {
+                               ret = NETDEV_TX_OK;
+                               goto fail;
+                       }
+
+                       /* DA SA BSSID */
+                       memcpy(hdr.addr1, skb->data, ETH_ALEN);
+                       memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
+                       memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
+                       hdrlen = 24;
+               }  else if (sdata->u.mgd.use_4addr &&
+                           cpu_to_be16(ethertype) != sdata->control_port_protocol) {
+                       fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
+                                         IEEE80211_FCTL_TODS);
                        /* RA TA DA SA */
+                       memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
                        memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
                        memcpy(hdr.addr3, skb->data, ETH_ALEN);
                        memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
@@ -1849,6 +1882,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
                } else {
                        fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
                        /* BSSID SA DA */
+                       memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
                        memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
                        memcpy(hdr.addr3, skb->data, ETH_ALEN);
                        hdrlen = 24;

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 6304ed63588a6e1909ca39676a44266f1eb62d1e..2f178f73943f5b3aa85e469add4884a1a1fb4ee0 100644 (file)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -396,8 +396,9 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
                }
                break;
        case cpu_to_le16(0):
-               if (iftype != NL80211_IFTYPE_ADHOC)
-                       return -1;
+               if (iftype != NL80211_IFTYPE_ADHOC &&
+                   iftype != NL80211_IFTYPE_STATION)
+                               return -1;
                break;
        }