Commit 97ffe757 authored by Johannes Berg's avatar Johannes Berg
Browse files

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: default avatarJohannes Berg <johannes.berg@intel.com>
parent 527871d7

net/mac80211/tx.c

+118 −70
Original line number Diff line number Diff line
@@ -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);

			}

		/* 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 @@ 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);



	/* sta is always NULL for mesh */

	if (sta) {

		authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);

		wme_sta = sta->sta.wme;

		}

		*sta_out = sta ?: ERR_PTR(-ENOENT);

	}



	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {

		/* For mesh, the use of the QoS header is mandatory */

	if (ieee80211_vif_is_mesh(&sdata->vif))

		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;

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