From d524215f6cad245249df8def19125ae6fd0bcc9b Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 8 Jan 2010 18:06:26 +0100 Subject: mac80211: use nullfunc frames for 4-addr sta detection To detect incoming 4-addr stations, hostapd needs to receive a 4-addr data frame from the remote station, so that it can create the AP VLAN for it. With this patch, the mlme code emits a 4-addr nullfunc frame immediately after assoc. On the AP side it also drops 4-addr nullfunc frames to the cooked monitor mode interface, if the interface hasn't been fully set up to receive 4-addr data frames yet. Signed-off-by: Felix Fietkau Signed-off-by: John W. Linville --- net/mac80211/mlme.c | 39 +++++++++++++++++++++++++++++++++++++++ net/mac80211/rx.c | 12 ++++++++++++ 2 files changed, 51 insertions(+) (limited to 'net') diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 5484cf930a8..0336dbb45ac 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -282,6 +282,38 @@ void ieee80211_send_nullfunc(struct ieee80211_local *local, ieee80211_tx_skb(sdata, skb); } +static void ieee80211_send_4addr_nullfunc(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata) +{ + struct sk_buff *skb; + struct ieee80211_hdr *nullfunc; + __le16 fc; + + if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION)) + return; + + skb = dev_alloc_skb(local->hw.extra_tx_headroom + 30); + if (!skb) { + printk(KERN_DEBUG "%s: failed to allocate buffer for 4addr " + "nullfunc frame\n", sdata->name); + return; + } + skb_reserve(skb, local->hw.extra_tx_headroom); + + nullfunc = (struct ieee80211_hdr *) skb_put(skb, 30); + memset(nullfunc, 0, 30); + fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC | + IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS); + nullfunc->frame_control = fc; + memcpy(nullfunc->addr1, sdata->u.mgd.bssid, ETH_ALEN); + memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN); + memcpy(nullfunc->addr3, sdata->u.mgd.bssid, ETH_ALEN); + memcpy(nullfunc->addr4, sdata->vif.addr, ETH_ALEN); + + IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; + ieee80211_tx_skb(sdata, skb); +} + /* spectrum management related things */ static void ieee80211_chswitch_work(struct work_struct *work) { @@ -1089,6 +1121,13 @@ static bool ieee80211_assoc_success(struct ieee80211_work *wk, bss_conf->assoc_capability = capab_info; ieee80211_set_associated(sdata, cbss, changed); + /* + * If we're using 4-addr mode, let the AP know that we're + * doing so, so that it can create the STA VLAN on its side + */ + if (ifmgd->use_4addr) + ieee80211_send_4addr_nullfunc(local, sdata); + /* * Start timer to probe the connection to the AP now. * Also start the timer that will detect beacon loss. diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index e12f39a9646..efa6d3689c5 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1111,6 +1111,18 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx) if (ieee80211_is_nullfunc(hdr->frame_control) || ieee80211_is_qos_nullfunc(hdr->frame_control)) { I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc); + + /* + * If we receive a 4-addr nullfunc frame from a STA + * that was not moved to a 4-addr STA vlan yet, drop + * the frame to the monitor interface, to make sure + * that hostapd sees it + */ + if (ieee80211_has_a4(hdr->frame_control) && + (rx->sdata->vif.type == NL80211_IFTYPE_AP || + (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN && + !rx->sdata->u.vlan.sta))) + return RX_DROP_MONITOR; /* * Update counter and free packet here to avoid * counting this as a dropped packed. -- cgit v1.2.3