mac80211: factor out station lookup from ieee80211_build_hdr()
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>
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 018f029..e5d679f38 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1789,6 +1789,91 @@
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 @@
*/
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 @@
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 @@
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 @@
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 @@
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 @@
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);
- }
+ /* we already did checks when looking up the RA STA */
+ tdls_peer = test_sta_flag(sta, WLAN_STA_TDLS_PEER);
- 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;
- }
-
- /* 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 @@
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 @@
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 @@
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 @@
.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;