mac80211: partially fix skb->cb use

This patch fixes mac80211 to not use the skb->cb over the queue step
from virtual interfaces to the master. The patch also, for now,
disables aggregation because that would still require requeuing,
will fix that in a separate patch. There are two other places (software
requeue and powersaving stations) where requeue can happen, but that is
not currently used by any drivers/not possible to use respectively.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 30 insertions, 39 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 4e0c9227418..84640172d65 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -485,6 +485,9 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb)
 	C(head);
 	C(data);
 	C(truesize);
+#if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
+	C(do_not_encrypt);
+#endif
 	atomic_set(&n->users, 1);
 
 	atomic_inc(&(skb_shinfo(skb)->dataref));
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index b5830f7055c..a4c5b90de76 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1233,18 +1233,12 @@ static void ieee80211_tasklet_handler(unsigned long data)
 /* Remove added headers (e.g., QoS control), encryption header/MIC, etc. to
  * make a prepared TX frame (one that has been given to hw) to look like brand
  * new IEEE 802.11 frame that is ready to go through TX processing again.
- * Also, tx_packet_data in cb is restored from tx_control. */
+ */
 static void ieee80211_remove_tx_extra(struct ieee80211_local *local,
 				      struct ieee80211_key *key,
 				      struct sk_buff *skb)
 {
 	int hdrlen, iv_len, mic_len;
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-
-	info->flags &=	IEEE80211_TX_CTL_REQ_TX_STATUS |
-			IEEE80211_TX_CTL_DO_NOT_ENCRYPT |
-			IEEE80211_TX_CTL_REQUEUE |
-			IEEE80211_TX_CTL_EAPOL_FRAME;
 
 	hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index d7c371e36bf..35eb767cbcb 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -606,7 +606,6 @@ void ieee80211_sta_tx(struct net_device *dev, struct sk_buff *skb,
 		      int encrypt)
 {
 	struct ieee80211_sub_if_data *sdata;
-	struct ieee80211_tx_info *info;
 
 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	skb->dev = sdata->local->mdev;
@@ -614,11 +613,8 @@ void ieee80211_sta_tx(struct net_device *dev, struct sk_buff *skb,
 	skb_set_network_header(skb, 0);
 	skb_set_transport_header(skb, 0);
 
-	info = IEEE80211_SKB_CB(skb);
-	memset(info, 0, sizeof(struct ieee80211_tx_info));
-	info->control.ifindex = sdata->dev->ifindex;
-	if (!encrypt)
-		info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
+	skb->iif = sdata->dev->ifindex;
+	skb->do_not_encrypt = !encrypt;
 
 	dev_queue_xmit(skb);
 }
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index c5f78059c6c..69019e94387 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -439,14 +439,14 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 	u16 fc = tx->fc;
 
-	if (unlikely(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT))
+	if (unlikely(tx->skb->do_not_encrypt))
 		tx->key = NULL;
 	else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
 		tx->key = key;
 	else if ((key = rcu_dereference(tx->sdata->default_key)))
 		tx->key = key;
 	else if (tx->sdata->drop_unencrypted &&
-		 !(info->flags & IEEE80211_TX_CTL_EAPOL_FRAME) &&
+		 (tx->skb->protocol != cpu_to_be16(ETH_P_PAE)) &&
 		 !(info->flags & IEEE80211_TX_CTL_INJECTED)) {
 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
 		return TX_DROP;
@@ -476,7 +476,7 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
 	}
 
 	if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
-		info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
+		tx->skb->do_not_encrypt = 1;
 
 	return TX_CONTINUE;
 }
@@ -732,6 +732,7 @@ ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
 		memcpy(skb_put(frag, copylen), pos, copylen);
 		memcpy(frag->cb, first->cb, sizeof(frag->cb));
 		skb_copy_queue_mapping(frag, first);
+		frag->do_not_encrypt = first->do_not_encrypt;
 
 		pos += copylen;
 		left -= copylen;
@@ -852,7 +853,7 @@ __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
 
 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
 
-	info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
+	skb->do_not_encrypt = 1;
 	info->flags |= IEEE80211_TX_CTL_INJECTED;
 	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
 
@@ -925,8 +926,7 @@ __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
 				skb_trim(skb, skb->len - FCS_LEN);
 			}
 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
-				info->flags &=
-					~IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
+				tx->skb->do_not_encrypt = 0;
 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
 				tx->flags |= IEEE80211_TX_FRAGMENTED;
 			break;
@@ -1042,10 +1042,9 @@ static int ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
 				struct sk_buff *skb,
 				struct net_device *mdev)
 {
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct net_device *dev;
 
-	dev = dev_get_by_index(&init_net, info->control.ifindex);
+	dev = dev_get_by_index(&init_net, skb->iif);
 	if (unlikely(dev && !is_ieee80211_device(dev, mdev))) {
 		dev_put(dev);
 		dev = NULL;
@@ -1306,8 +1305,8 @@ int ieee80211_master_start_xmit(struct sk_buff *skb,
 	bool may_encrypt;
 	int ret;
 
-	if (info->control.ifindex)
-		odev = dev_get_by_index(&init_net, info->control.ifindex);
+	if (skb->iif)
+		odev = dev_get_by_index(&init_net, skb->iif);
 	if (unlikely(odev && !is_ieee80211_device(odev, dev))) {
 		dev_put(odev);
 		odev = NULL;
@@ -1321,9 +1320,13 @@ int ieee80211_master_start_xmit(struct sk_buff *skb,
 		return 0;
 	}
 
+	memset(info, 0, sizeof(*info));
+
+	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
+
 	osdata = IEEE80211_DEV_TO_SUB_IF(odev);
 
-	may_encrypt = !(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT);
+	may_encrypt = !skb->do_not_encrypt;
 
 	headroom = osdata->local->tx_headroom;
 	if (may_encrypt)
@@ -1348,7 +1351,6 @@ int ieee80211_monitor_start_xmit(struct sk_buff *skb,
 				 struct net_device *dev)
 {
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_radiotap_header *prthdr =
 		(struct ieee80211_radiotap_header *)skb->data;
 	u16 len_rthdr;
@@ -1371,11 +1373,11 @@ int ieee80211_monitor_start_xmit(struct sk_buff *skb,
 	skb->dev = local->mdev;
 
 	/* needed because we set skb device to master */
-	info->control.ifindex = dev->ifindex;
+	skb->iif = dev->ifindex;
 
-	info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
-	/* Interfaces should always request a status report */
-	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
+	/* sometimes we do encrypt injected frames, will be fixed
+	 * up in radiotap parser if not wanted */
+	skb->do_not_encrypt = 0;
 
 	/*
 	 * fix up the pointers accounting for the radiotap
@@ -1419,7 +1421,6 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
 			       struct net_device *dev)
 {
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-	struct ieee80211_tx_info *info;
 	struct ieee80211_sub_if_data *sdata;
 	int ret = 1, head_need;
 	u16 ethertype, hdrlen,  meshhdrlen = 0;
@@ -1645,14 +1646,7 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
 	nh_pos += hdrlen;
 	h_pos += hdrlen;
 
-	info = IEEE80211_SKB_CB(skb);
-	memset(info, 0, sizeof(*info));
-	info->control.ifindex = dev->ifindex;
-	if (ethertype == ETH_P_PAE)
-		info->flags |= IEEE80211_TX_CTL_EAPOL_FRAME;
-
-	/* Interfaces should always request a status report */
-	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
+	skb->iif = dev->ifindex;
 
 	skb->dev = local->mdev;
 	dev->stats.tx_packets++;
@@ -1922,6 +1916,8 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
 
 	info = IEEE80211_SKB_CB(skb);
 
+	skb->do_not_encrypt = 1;
+
 	info->band = band;
 	rate_control_get_rate(local->mdev, sband, skb, &rsel);
 
@@ -1940,7 +1936,6 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
 	info->tx_rate_idx = rsel.rate_idx;
 
 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
-	info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
 	info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
 	if (sdata->bss_conf.use_short_preamble &&
diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
index 07edda0b8a5..28437f0001d 100644
--- a/net/mac80211/wme.c
+++ b/net/mac80211/wme.c
@@ -188,6 +188,9 @@ int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
 {
 	int i;
 
+	/* XXX: currently broken due to cb/requeue use */
+	return -EPERM;
+
 	/* prepare the filter and save it for the SW queue
 	 * matching the received HW queue */