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>

13 files changed, 40 insertions, 52 deletions

diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c
index 1106d1c..ff3fad7 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -1237,7 +1237,7 @@ ath5k_txbuf_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
 
 	pktlen = skb->len;
 
-	if (!(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT)) {
+	if (info->control.hw_key) {
 		keyidx = info->control.hw_key->hw_key_idx;
 		pktlen += info->control.icv_len;
 	}
diff --git a/drivers/net/wireless/b43/xmit.c b/drivers/net/wireless/b43/xmit.c
index 8d54502..9dda816 100644
--- a/drivers/net/wireless/b43/xmit.c
+++ b/drivers/net/wireless/b43/xmit.c
@@ -192,7 +192,7 @@ int b43_generate_txhdr(struct b43_wldev *dev,
 	const struct b43_phy *phy = &dev->phy;
 	const struct ieee80211_hdr *wlhdr =
 	    (const struct ieee80211_hdr *)fragment_data;
-	int use_encryption = (!(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT));
+	int use_encryption = !!info->control.hw_key;
 	__le16 fctl = wlhdr->frame_control;
 	struct ieee80211_rate *fbrate;
 	u8 rate, rate_fb;
diff --git a/drivers/net/wireless/b43legacy/xmit.c b/drivers/net/wireless/b43legacy/xmit.c
index e969ed8..68e1f8c 100644
--- a/drivers/net/wireless/b43legacy/xmit.c
+++ b/drivers/net/wireless/b43legacy/xmit.c
@@ -192,7 +192,7 @@ static int generate_txhdr_fw3(struct b43legacy_wldev *dev,
 			       u16 cookie)
 {
 	const struct ieee80211_hdr *wlhdr;
-	int use_encryption = (!(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT));
+	int use_encryption = !!info->control.hw_key;
 	u16 fctl;
 	u8 rate;
 	struct ieee80211_rate *rate_fb;
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 9b50b10..f72cd0b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -906,7 +906,7 @@ int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
 	 * first entry */
 	iwl_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len);
 
-	if (!(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT))
+	if (info->control.hw_key)
 		iwl_tx_cmd_build_hwcrypto(priv, info, tx_cmd, skb, sta_id);
 
 	/* Set up TFD's 2nd entry to point directly to remainder of skb,
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 05121f3..7c82ecf 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -2667,7 +2667,7 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv, struct sk_buff *skb)
 	 * first entry */
 	iwl3945_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len);
 
-	if (!(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT))
+	if (info->control.hw_key)
 		iwl3945_build_tx_cmd_hwcrypto(priv, info, out_cmd, skb, 0);
 
 	/* Set up TFD's 2nd entry to point directly to remainder of skb,
diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
index 042ab00..c3ee4ec 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -63,7 +63,7 @@ static int rt2x00mac_tx_rts_cts(struct rt2x00_dev *rt2x00dev,
 	 */
 	memcpy(skb->cb, frag_skb->cb, sizeof(skb->cb));
 	rts_info = IEEE80211_SKB_CB(skb);
-	rts_info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
+	rts_info->control.hw_key = NULL;
 	rts_info->flags &= ~IEEE80211_TX_CTL_USE_RTS_CTS;
 	rts_info->flags &= ~IEEE80211_TX_CTL_USE_CTS_PROTECT;
 	rts_info->flags &= ~IEEE80211_TX_CTL_REQ_TX_STATUS;
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 7ea44f6..a640385 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -316,7 +316,10 @@ struct sk_buff {
 #ifdef CONFIG_IPV6_NDISC_NODETYPE
 	__u8			ndisc_nodetype:2;
 #endif
-	/* 14 bit hole */
+#if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
+	__u8			do_not_encrypt:1;
+#endif
+	/* 0/13/14 bit hole */
 
 #ifdef CONFIG_NET_DMA
 	dma_cookie_t		dma_cookie;
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 74487f2..b527210 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -206,8 +206,6 @@ struct ieee80211_bss_conf {
  * These flags are used with the @flags member of &ieee80211_tx_info.
  *
  * @IEEE80211_TX_CTL_REQ_TX_STATUS: request TX status callback for this frame.
- * @IEEE80211_TX_CTL_DO_NOT_ENCRYPT: send this frame without encryption;
- *	e.g., for EAPOL frame
  * @IEEE80211_TX_CTL_USE_RTS_CTS: use RTS-CTS before sending frame
  * @IEEE80211_TX_CTL_USE_CTS_PROTECT: use CTS protection for the frame (e.g.,
  *	for combined 802.11g / 802.11b networks)
@@ -220,7 +218,6 @@ struct ieee80211_bss_conf {
  * @IEEE80211_TX_CTL_SHORT_PREAMBLE: TBD
  * @IEEE80211_TX_CTL_LONG_RETRY_LIMIT: this frame should be send using the
  *	through set_retry_limit configured long retry value
- * @IEEE80211_TX_CTL_EAPOL_FRAME: internal to mac80211
  * @IEEE80211_TX_CTL_SEND_AFTER_DTIM: send this frame after DTIM beacon
  * @IEEE80211_TX_CTL_AMPDU: this frame should be sent as part of an A-MPDU
  * @IEEE80211_TX_CTL_OFDM_HT: this frame can be sent in HT OFDM rates. number
@@ -253,7 +250,6 @@ struct ieee80211_bss_conf {
  */
 enum mac80211_tx_control_flags {
 	IEEE80211_TX_CTL_REQ_TX_STATUS		= BIT(0),
-	IEEE80211_TX_CTL_DO_NOT_ENCRYPT		= BIT(1),
 	IEEE80211_TX_CTL_USE_RTS_CTS		= BIT(2),
 	IEEE80211_TX_CTL_USE_CTS_PROTECT	= BIT(3),
 	IEEE80211_TX_CTL_NO_ACK			= BIT(4),
@@ -263,7 +259,6 @@ enum mac80211_tx_control_flags {
 	IEEE80211_TX_CTL_FIRST_FRAGMENT		= BIT(8),
 	IEEE80211_TX_CTL_SHORT_PREAMBLE		= BIT(9),
 	IEEE80211_TX_CTL_LONG_RETRY_LIMIT	= BIT(10),
-	IEEE80211_TX_CTL_EAPOL_FRAME		= BIT(11),
 	IEEE80211_TX_CTL_SEND_AFTER_DTIM	= BIT(12),
 	IEEE80211_TX_CTL_AMPDU			= BIT(13),
 	IEEE80211_TX_CTL_OFDM_HT		= BIT(14),
@@ -323,7 +318,6 @@ struct ieee80211_tx_info {
 			struct ieee80211_vif *vif;
 			struct ieee80211_key_conf *hw_key;
 			unsigned long jiffies;
-			int ifindex;
 			u16 aid;
 			s8 rts_cts_rate_idx, alt_retry_rate_idx;
 			u8 retry_limit;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 4e0c922..8464017 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 b5830f7..a4c5b90 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 d7c371e..35eb767 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 c5f7805..69019e9 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 07edda0..28437f0 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 */