From 97ffe75791b3e9c0797d5891070e41321c3beccb Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Sat, 21 Mar 2015 09:13:45 +0100 Subject: [PATCH] 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 --- net/mac80211/tx.c | 188 +++++++++++++++++++++++++++++----------------- 1 file changed, 118 insertions(+), 70 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 018f029d0c95..e5d679f38cc1 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -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); - 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;