mac80211: use channel contexts

Instead of operating on a single channel only,
use the new channel context infrastructure in
all mac80211 code.

This enables drivers that want to use the new
channel context infrastructure to use multiple
channels, while nothing should change for all
the other drivers that don't support it.

Right now this disables both TX power settings
and spatial multiplexing powersave. Both need
to be re-enabled on a channel context basis.

Additionally, when channel contexts are used
drop the connection when channel switch is
received rather than trying to handle it. This
will have to be improved later.

[With fixes from Eliad and Emmanuel incorporated]
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 115 insertions, 68 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index c9bf83f36657..eee448ac71ff 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -324,11 +324,6 @@ static void purge_old_ps_buffers(struct ieee80211_local *local)
 	struct ieee80211_sub_if_data *sdata;
 	struct sta_info *sta;
 
-	/*
-	 * virtual interfaces are protected by RCU
-	 */
-	rcu_read_lock();
-
 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 		struct ieee80211_if_ap *ap;
 		if (sdata->vif.type != NL80211_IFTYPE_AP)
@@ -360,8 +355,6 @@ static void purge_old_ps_buffers(struct ieee80211_local *local)
 		}
 	}
 
-	rcu_read_unlock();
-
 	local->total_ps_buffered = total;
 	ps_dbg_hw(&local->hw, "PS buffers full - purged %d frames\n", purged);
 }
@@ -1372,7 +1365,8 @@ static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
  * Returns false if the frame couldn't be transmitted but was queued instead.
  */
 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
-			 struct sk_buff *skb, bool txpending)
+			 struct sk_buff *skb, bool txpending,
+			 enum ieee80211_band band)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_data tx;
@@ -1386,20 +1380,18 @@ static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
 		return true;
 	}
 
-	rcu_read_lock();
-
 	/* initialises tx */
 	led_len = skb->len;
 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
 
 	if (unlikely(res_prepare == TX_DROP)) {
 		ieee80211_free_txskb(&local->hw, skb);
-		goto out;
+		return true;
 	} else if (unlikely(res_prepare == TX_QUEUED)) {
-		goto out;
+		return true;
 	}
 
-	info->band = local->hw.conf.channel->band;
+	info->band = band;
 
 	/* set up hw_queue value early */
 	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
@@ -1410,8 +1402,7 @@ static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
 	if (!invoke_tx_handlers(&tx))
 		result = __ieee80211_tx(local, &tx.skbs, led_len,
 					tx.sta, txpending);
- out:
-	rcu_read_unlock();
+
 	return result;
 }
 
@@ -1446,7 +1437,8 @@ static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
 	return 0;
 }
 
-void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
+void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
+		    enum ieee80211_band band)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
@@ -1454,8 +1446,6 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 	int headroom;
 	bool may_encrypt;
 
-	rcu_read_lock();
-
 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
 
 	headroom = local->tx_headroom;
@@ -1466,7 +1456,6 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 
 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
 		ieee80211_free_txskb(&local->hw, skb);
-		rcu_read_unlock();
 		return;
 	}
 
@@ -1478,13 +1467,11 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 	    !is_multicast_ether_addr(hdr->addr1) &&
 	    mesh_nexthop_resolve(skb, sdata)) {
 		/* skb queued: don't free */
-		rcu_read_unlock();
 		return;
 	}
 
 	ieee80211_set_qos_hdr(sdata, skb);
-	ieee80211_tx(sdata, skb, false);
-	rcu_read_unlock();
+	ieee80211_tx(sdata, skb, false, band);
 }
 
 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
@@ -1574,7 +1561,8 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
 					 struct net_device *dev)
 {
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-	struct ieee80211_channel *chan = local->hw.conf.channel;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *chan;
 	struct ieee80211_radiotap_header *prthdr =
 		(struct ieee80211_radiotap_header *)skb->data;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
@@ -1583,26 +1571,6 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
 	u16 len_rthdr;
 	int hdrlen;
 
-	/*
-	 * Frame injection is not allowed if beaconing is not allowed
-	 * or if we need radar detection. Beaconing is usually not allowed when
-	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
-	 * Passive scan is also used in world regulatory domains where
-	 * your country is not known and as such it should be treated as
-	 * NO TX unless the channel is explicitly allowed in which case
-	 * your current regulatory domain would not have the passive scan
-	 * flag.
-	 *
-	 * Since AP mode uses monitor interfaces to inject/TX management
-	 * frames we can make AP mode the exception to this rule once it
-	 * supports radar detection as its implementation can deal with
-	 * radar detection by itself. We can do that later by adding a
-	 * monitor flag interfaces used for AP support.
-	 */
-	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
-	     IEEE80211_CHAN_PASSIVE_SCAN)))
-		goto fail;
-
 	/* check for not even having the fixed radiotap header part */
 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
 		goto fail; /* too short to be possibly valid */
@@ -1688,11 +1656,45 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
 		}
 	}
 
-	ieee80211_xmit(sdata, skb);
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (!chanctx_conf) {
+		tmp_sdata = rcu_dereference(local->monitor_sdata);
+		if (tmp_sdata)
+			chanctx_conf =
+				rcu_dereference(tmp_sdata->vif.chanctx_conf);
+	}
+	if (!chanctx_conf)
+		goto fail_rcu;
+
+	chan = chanctx_conf->channel;
+
+	/*
+	 * Frame injection is not allowed if beaconing is not allowed
+	 * or if we need radar detection. Beaconing is usually not allowed when
+	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
+	 * Passive scan is also used in world regulatory domains where
+	 * your country is not known and as such it should be treated as
+	 * NO TX unless the channel is explicitly allowed in which case
+	 * your current regulatory domain would not have the passive scan
+	 * flag.
+	 *
+	 * Since AP mode uses monitor interfaces to inject/TX management
+	 * frames we can make AP mode the exception to this rule once it
+	 * supports radar detection as its implementation can deal with
+	 * radar detection by itself. We can do that later by adding a
+	 * monitor flag interfaces used for AP support.
+	 */
+	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
+			    IEEE80211_CHAN_PASSIVE_SCAN)))
+		goto fail_rcu;
+
+	ieee80211_xmit(sdata, skb, chan->band);
 	rcu_read_unlock();
 
 	return NETDEV_TX_OK;
 
+fail_rcu:
+	rcu_read_unlock();
 fail:
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
@@ -1734,6 +1736,9 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 	bool multicast;
 	u32 info_flags = 0;
 	u16 info_id = 0;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_sub_if_data *ap_sdata;
+	enum ieee80211_band band;
 
 	if (unlikely(skb->len < ETH_HLEN))
 		goto fail;
@@ -1743,9 +1748,10 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 	ethertype = (skb->data[12] << 8) | skb->data[13];
 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
 
+	rcu_read_lock();
+
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_AP_VLAN:
-		rcu_read_lock();
 		sta = rcu_dereference(sdata->u.vlan.sta);
 		if (sta) {
 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
@@ -1758,7 +1764,12 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
 		}
-		rcu_read_unlock();
+		ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
+					u.ap);
+		chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		if (sta)
 			break;
 		/* fall through */
@@ -1769,6 +1780,11 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
 		hdrlen = 24;
+		if (sdata->vif.type == NL80211_IFTYPE_AP)
+			chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 	case NL80211_IFTYPE_WDS:
 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
@@ -1778,15 +1794,20 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
 		hdrlen = 30;
+		/*
+		 * This is the exception! WDS style interfaces are prohibited
+		 * when channel contexts are in used so this must be valid
+		 */
+		band = local->hw.conf.channel->band;
 		break;
 #ifdef CONFIG_MAC80211_MESH
 	case NL80211_IFTYPE_MESH_POINT:
 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
 			/* Do not send frames with mesh_ttl == 0 */
 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
-			goto fail;
+			goto fail_rcu;
 		}
-		rcu_read_lock();
+
 		if (!is_multicast_ether_addr(skb->data)) {
 			mpath = mesh_path_lookup(skb->data, sdata);
 			if (!mpath)
@@ -1803,7 +1824,6 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
 					skb->data, skb->data + ETH_ALEN);
-			rcu_read_unlock();
 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
 					sdata, NULL, NULL);
 		} else {
@@ -1819,7 +1839,6 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 				mesh_da = mppath->mpp;
 			else if (mpath)
 				mesh_da = mpath->dst;
-			rcu_read_unlock();
 
 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
 					mesh_da, sdata->vif.addr);
@@ -1839,13 +1858,16 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 							skb->data + ETH_ALEN);
 
 		}
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 #endif
 	case NL80211_IFTYPE_STATION:
 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
 			bool tdls_peer = false;
 
-			rcu_read_lock();
 			sta = sta_info_get(sdata, skb->data);
 			if (sta) {
 				authorized = test_sta_flag(sta,
@@ -1856,7 +1878,6 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 				tdls_auth = test_sta_flag(sta,
 						WLAN_STA_TDLS_PEER_AUTH);
 			}
-			rcu_read_unlock();
 
 			/*
 			 * If the TDLS link is enabled, send everything
@@ -1871,7 +1892,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		if (tdls_direct) {
 			/* link during setup - throw out frames to peer */
 			if (!tdls_auth)
-				goto fail;
+				goto fail_rcu;
 
 			/* DA SA BSSID */
 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
@@ -1896,6 +1917,10 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
 			hdrlen = 24;
 		}
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 	case NL80211_IFTYPE_ADHOC:
 		/* DA SA BSSID */
@@ -1903,9 +1928,13 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
 		hdrlen = 24;
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 	default:
-		goto fail;
+		goto fail_rcu;
 	}
 
 	/*
@@ -1915,13 +1944,11 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 	 */
 	multicast = is_multicast_ether_addr(hdr.addr1);
 	if (!multicast) {
-		rcu_read_lock();
 		sta = sta_info_get(sdata, hdr.addr1);
 		if (sta) {
 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
 		}
-		rcu_read_unlock();
 	}
 
 	/* For mesh, the use of the QoS header is mandatory */
@@ -1949,7 +1976,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 
 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
 
-		goto fail;
+		goto fail_rcu;
 	}
 
 	if (unlikely(!multicast && skb->sk &&
@@ -2004,7 +2031,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		kfree_skb(tmp_skb);
 
 		if (!skb)
-			goto fail;
+			goto fail_rcu;
 	}
 
 	hdr.frame_control = fc;
@@ -2052,7 +2079,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		head_need = max_t(int, 0, head_need);
 		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
 			ieee80211_free_txskb(&local->hw, skb);
-			return NETDEV_TX_OK;
+			goto fail_rcu;
 		}
 	}
 
@@ -2104,10 +2131,13 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 	info->flags = info_flags;
 	info->ack_frame_id = info_id;
 
-	ieee80211_xmit(sdata, skb);
+	ieee80211_xmit(sdata, skb, band);
+	rcu_read_unlock();
 
 	return NETDEV_TX_OK;
 
+ fail_rcu:
+	rcu_read_unlock();
  fail:
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK;
@@ -2139,11 +2169,18 @@ static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
 	struct sta_info *sta;
 	struct ieee80211_hdr *hdr;
 	bool result;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	sdata = vif_to_sdata(info->control.vif);
 
 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
-		result = ieee80211_tx(sdata, skb, true);
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (unlikely(!chanctx_conf)) {
+			dev_kfree_skb(skb);
+			return true;
+		}
+		result = ieee80211_tx(sdata, skb, true,
+				      chanctx_conf->channel->band);
 	} else {
 		struct sk_buff_head skbs;
 
@@ -2285,14 +2322,16 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 	struct ieee80211_sub_if_data *sdata = NULL;
 	struct ieee80211_if_ap *ap = NULL;
 	struct beacon_data *beacon;
-	enum ieee80211_band band = local->oper_channel->band;
+	enum ieee80211_band band;
 	struct ieee80211_tx_rate_control txrc;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	rcu_read_lock();
 
 	sdata = vif_to_sdata(vif);
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 
-	if (!ieee80211_sdata_running(sdata))
+	if (!ieee80211_sdata_running(sdata) || !chanctx_conf)
 		goto out;
 
 	if (tim_offset)
@@ -2409,6 +2448,8 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 		*pos++ = WLAN_EID_SSID;
 		*pos++ = 0x0;
 
+		band = chanctx_conf->channel->band;
+
 		if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 		    mesh_add_ds_params_ie(skb, sdata) ||
 		    ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
@@ -2426,6 +2467,8 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 		goto out;
 	}
 
+	band = chanctx_conf->channel->band;
+
 	info = IEEE80211_SKB_CB(skb);
 
 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
@@ -2656,14 +2699,17 @@ ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
 	struct ieee80211_if_ap *bss = NULL;
 	struct beacon_data *beacon;
 	struct ieee80211_tx_info *info;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	sdata = vif_to_sdata(vif);
 	bss = &sdata->u.ap;
 
 	rcu_read_lock();
 	beacon = rcu_dereference(bss->beacon);
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 
-	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
+	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head ||
+	    !chanctx_conf)
 		goto out;
 
 	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
@@ -2693,7 +2739,7 @@ ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
 	info = IEEE80211_SKB_CB(skb);
 
 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
-	info->band = local->oper_channel->band;
+	info->band = chanctx_conf->channel->band;
 
 	if (invoke_tx_handlers(&tx))
 		skb = NULL;
@@ -2704,8 +2750,9 @@ ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
 
-void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
-			  struct sk_buff *skb, int tid)
+void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
+				 struct sk_buff *skb, int tid,
+				 enum ieee80211_band band)
 {
 	int ac = ieee802_1d_to_ac[tid & 7];
 
@@ -2722,6 +2769,6 @@ void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
 	 * requirements are that we do not come into tx with bhs on.
 	 */
 	local_bh_disable();
-	ieee80211_xmit(sdata, skb);
+	ieee80211_xmit(sdata, skb, band);
 	local_bh_enable();
 }