]> git.karo-electronics.de Git - linux-beck.git/commitdiff
mac80211: factor out station lookup from ieee80211_build_hdr()
authorJohannes Berg <johannes.berg@intel.com>
Sat, 21 Mar 2015 08:13:45 +0000 (09:13 +0100)
committerJohannes Berg <johannes.berg@intel.com>
Mon, 30 Mar 2015 08:47:19 +0000 (10:47 +0200)
In order to look up the RA station earlier to implement a TX
fastpath, factor out the lookup from ieee80211_build_hdr().
To always have a valid station pointer, also move some of the
checks into the new function.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
net/mac80211/tx.c

index 018f029d0c95701460ffeea630042f436f0d4d79..e5d679f38cc10bc6600d2cd919b089ce5b51525b 100644 (file)
@@ -1789,6 +1789,91 @@ fail:
        return NETDEV_TX_OK; /* meaning, we dealt with the skb */
 }
 
+static inline bool ieee80211_is_tdls_setup(struct sk_buff *skb)
+{
+       u16 ethertype = (skb->data[12] << 8) | skb->data[13];
+
+       return ethertype == ETH_P_TDLS &&
+              skb->len > 14 &&
+              skb->data[14] == WLAN_TDLS_SNAP_RFTYPE;
+}
+
+static int ieee80211_lookup_ra_sta(struct ieee80211_sub_if_data *sdata,
+                                  struct sk_buff *skb,
+                                  struct sta_info **sta_out)
+{
+       struct sta_info *sta;
+
+       switch (sdata->vif.type) {
+       case NL80211_IFTYPE_AP_VLAN:
+               sta = rcu_dereference(sdata->u.vlan.sta);
+               if (sta) {
+                       *sta_out = sta;
+                       return 0;
+               } else if (sdata->wdev.use_4addr) {
+                       return -ENOLINK;
+               }
+               /* fall through */
+       case NL80211_IFTYPE_AP:
+       case NL80211_IFTYPE_OCB:
+       case NL80211_IFTYPE_ADHOC:
+               if (is_multicast_ether_addr(skb->data)) {
+                       *sta_out = ERR_PTR(-ENOENT);
+                       return 0;
+               }
+               sta = sta_info_get_bss(sdata, skb->data);
+               break;
+       case NL80211_IFTYPE_WDS:
+               sta = sta_info_get(sdata, sdata->u.wds.remote_addr);
+               break;
+#ifdef CONFIG_MAC80211_MESH
+       case NL80211_IFTYPE_MESH_POINT:
+               /* determined much later */
+               *sta_out = NULL;
+               return 0;
+#endif
+       case NL80211_IFTYPE_STATION:
+               if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
+                       sta = sta_info_get(sdata, skb->data);
+                       if (sta) {
+                               bool tdls_peer, tdls_auth;
+
+                               tdls_peer = test_sta_flag(sta,
+                                                         WLAN_STA_TDLS_PEER);
+                               tdls_auth = test_sta_flag(sta,
+                                               WLAN_STA_TDLS_PEER_AUTH);
+
+                               if (tdls_peer && tdls_auth) {
+                                       *sta_out = sta;
+                                       return 0;
+                               }
+
+                               /*
+                                * TDLS link during setup - throw out frames to
+                                * peer. 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 &&
+                                   !ieee80211_is_tdls_setup(skb))
+                                       return -EINVAL;
+                       }
+
+               }
+
+               sta = sta_info_get(sdata, sdata->u.mgd.bssid);
+               if (!sta)
+                       return -ENOLINK;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       *sta_out = sta ?: ERR_PTR(-ENOENT);
+       return 0;
+}
+
 /**
  * ieee80211_build_hdr - build 802.11 header in the given frame
  * @sdata: virtual interface to build the header for
@@ -1809,7 +1894,7 @@ fail:
  */
 static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
                                           struct sk_buff *skb, u32 info_flags,
-                                          struct sta_info **sta_out)
+                                          struct sta_info *sta)
 {
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_tx_info *info;
@@ -1822,17 +1907,18 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
        const u8 *encaps_data;
        int encaps_len, skip_header_bytes;
        int nh_pos, h_pos;
-       struct sta_info *sta = NULL;
-       bool wme_sta = false, authorized = false, tdls_auth = false;
-       bool tdls_peer = false, tdls_setup_frame = false;
+       bool wme_sta = false, authorized = false;
+       bool tdls_peer;
        bool multicast;
-       bool have_station = false;
        u16 info_id = 0;
        struct ieee80211_chanctx_conf *chanctx_conf;
        struct ieee80211_sub_if_data *ap_sdata;
        enum ieee80211_band band;
        int ret;
 
+       if (IS_ERR(sta))
+               sta = NULL;
+
        /* convert Ethernet header to proper 802.11 header (based on
         * operation mode) */
        ethertype = (skb->data[12] << 8) | skb->data[13];
@@ -1840,8 +1926,7 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
 
        switch (sdata->vif.type) {
        case NL80211_IFTYPE_AP_VLAN:
-               sta = rcu_dereference(sdata->u.vlan.sta);
-               if (sta) {
+               if (sdata->wdev.use_4addr) {
                        fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
                        /* RA TA DA SA */
                        memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
@@ -1851,11 +1936,6 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
                        hdrlen = 30;
                        authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
                        wme_sta = sta->sta.wme;
-                       have_station = true;
-                       *sta_out = sta;
-               } else if (sdata->wdev.use_4addr) {
-                       ret = -ENOLINK;
-                       goto free;
                }
                ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
                                        u.ap);
@@ -1865,7 +1945,7 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
                        goto free;
                }
                band = chanctx_conf->def.chan->band;
-               if (sta)
+               if (sdata->wdev.use_4addr)
                        break;
                /* fall through */
        case NL80211_IFTYPE_AP:
@@ -1969,44 +2049,15 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
                break;
 #endif
        case NL80211_IFTYPE_STATION:
-               if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
-                       sta = sta_info_get(sdata, skb->data);
-                       if (sta) {
-                               tdls_peer = test_sta_flag(sta,
-                                                         WLAN_STA_TDLS_PEER);
-                               tdls_auth = test_sta_flag(sta,
-                                               WLAN_STA_TDLS_PEER_AUTH);
-                       }
-
-                       if (tdls_peer)
-                               tdls_setup_frame =
-                                       ethertype == ETH_P_TDLS &&
-                                       skb->len > 14 &&
-                                       skb->data[14] == WLAN_TDLS_SNAP_RFTYPE;
-               }
-
-               /*
-                * 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) {
-                       ret = -EINVAL;
-                       goto free;
-               }
+               /* we already did checks when looking up the RA STA */
+               tdls_peer = test_sta_flag(sta, WLAN_STA_TDLS_PEER);
 
-               /* send direct packets to authorized TDLS peers */
-               if (tdls_peer && tdls_auth) {
+               if (tdls_peer) {
                        /* 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;
-                       have_station = true;
-                       authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
-                       wme_sta = sta->sta.wme;
-                       *sta_out = sta;
                }  else if (sdata->u.mgd.use_4addr &&
                            cpu_to_be16(ethertype) != sdata->control_port_protocol) {
                        fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
@@ -2063,30 +2114,16 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
                goto free;
        }
 
-       /*
-        * There's no need to try to look up the destination station
-        * if it is a multicast address. In mesh, there's no need to
-        * look up the station at all as it always must be QoS capable
-        * and mesh mode checks authorization later.
-        */
        multicast = is_multicast_ether_addr(hdr.addr1);
-       if (multicast) {
-               *sta_out = ERR_PTR(-ENOENT);
-       } else if (!have_station && !ieee80211_vif_is_mesh(&sdata->vif)) {
-               if (sdata->control_port_protocol == skb->protocol)
-                       sta = sta_info_get_bss(sdata, hdr.addr1);
-               else
-                       sta = sta_info_get(sdata, hdr.addr1);
-               if (sta) {
-                       authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
-                       wme_sta = sta->sta.wme;
-               }
-               *sta_out = sta ?: ERR_PTR(-ENOENT);
-       }
 
-       /* For mesh, the use of the QoS header is mandatory */
-       if (ieee80211_vif_is_mesh(&sdata->vif))
+       /* sta is always NULL for mesh */
+       if (sta) {
+               authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
+               wme_sta = sta->sta.wme;
+       } else if (ieee80211_vif_is_mesh(&sdata->vif)) {
+               /* For mesh, the use of the QoS header is mandatory */
                wme_sta = true;
+       }
 
        /* receiver does QoS (which also means we do) use it */
        if (wme_sta) {
@@ -2259,7 +2296,7 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
                                  u32 info_flags)
 {
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-       struct sta_info *sta = NULL;
+       struct sta_info *sta;
 
        if (unlikely(skb->len < ETH_HLEN)) {
                kfree_skb(skb);
@@ -2268,7 +2305,12 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 
        rcu_read_lock();
 
-       skb = ieee80211_build_hdr(sdata, skb, info_flags, &sta);
+       if (ieee80211_lookup_ra_sta(sdata, skb, &sta)) {
+               kfree_skb(skb);
+               goto out;
+       }
+
+       skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
        if (IS_ERR(skb))
                goto out;
 
@@ -2304,11 +2346,17 @@ ieee80211_build_data_template(struct ieee80211_sub_if_data *sdata,
                .local = sdata->local,
                .sdata = sdata,
        };
-       struct sta_info *sta_ignore;
+       struct sta_info *sta;
 
        rcu_read_lock();
 
-       skb = ieee80211_build_hdr(sdata, skb, info_flags, &sta_ignore);
+       if (ieee80211_lookup_ra_sta(sdata, skb, &sta)) {
+               kfree_skb(skb);
+               skb = ERR_PTR(-EINVAL);
+               goto out;
+       }
+
+       skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
        if (IS_ERR(skb))
                goto out;