mac80211: restructuring data Rx handlers

This patch restructures the Rx handlers chain by incorporating previously
handlers ieee80211_rx_h_802_1x_pae and ieee80211_rx_h_drop_unencrypted
into ieee80211_rx_h_data, already in 802.3 form. this scheme follows more
precisely after the IEEE802.11 data plane archituecture, and will prevent
code duplication to IEEE8021.11n A-MSDU handler.

added function:
 - ieee80211_data_to_8023: transfering 802.11 data frames to 802.3 frame
 - ieee80211_deliver_skb: delivering the 802.3 frames to upper stack
eliminated handlers:
 - ieee80211_rx_h_drop_unencrypted: now function ieee80211_drop_unencrypted
 - ieee80211_rx_h_802_1x_pae: now function ieee80211_802_1x_pae
changed handlers:
 - ieee80211_rx_h_data: now contains calls to four above function

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac80211/ieee80211_i.h

@@ -792,7 +792,7 @@ extern void *mac80211_wiphy_privid; /* for wiphy privid */
 extern const unsigned char rfc1042_header[6];
 extern const unsigned char bridge_tunnel_header[6];
 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len);
-int ieee80211_is_eapol(const struct sk_buff *skb);
+int ieee80211_is_eapol(const struct sk_buff *skb, int hdrlen);
 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
 			     int rate, int erp, int short_preamble);
 void mac80211_ev_michael_mic_failure(struct net_device *dev, int keyidx,

net/mac80211/rx.c

@@ -962,68 +962,64 @@ ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
 	return TXRX_CONTINUE;
 }
 
-static ieee80211_txrx_result
-ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
+static int
+ieee80211_drop_802_1x_pae(struct ieee80211_txrx_data *rx, int hdrlen)
 {
-	if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
+	if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb, hdrlen) &&
 	    rx->sdata->type != IEEE80211_IF_TYPE_STA &&
 	    (rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
-		return TXRX_CONTINUE;
+		return 0;
 
 	if (unlikely(rx->sdata->ieee802_1x &&
 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
 		     (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)) &&
-		     !ieee80211_is_eapol(rx->skb))) {
+		     !ieee80211_is_eapol(rx->skb, hdrlen))) {
 #ifdef CONFIG_MAC80211_DEBUG
-		struct ieee80211_hdr *hdr =
-			(struct ieee80211_hdr *) rx->skb->data;
-		DECLARE_MAC_BUF(mac);
-		printk(KERN_DEBUG "%s: dropped frame from %s"
-		       " (unauthorized port)\n", rx->dev->name,
-		       print_mac(mac, hdr->addr2));
+		printk(KERN_DEBUG "%s: dropped frame "
+		       "(unauthorized port)\n", rx->dev->name);
 #endif /* CONFIG_MAC80211_DEBUG */
-		return TXRX_DROP;
+		return -EACCES;
 	}
 
-	return TXRX_CONTINUE;
+	return 0;
 }
 
-static ieee80211_txrx_result
-ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx)
+static int
+ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx, int hdrlen)
 {
 	/*
 	 * Pass through unencrypted frames if the hardware has
 	 * decrypted them already.
 	 */
 	if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
-		return TXRX_CONTINUE;
+		return 0;
 
 	/* Drop unencrypted frames if key is set. */
 	if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
 		     (rx->key || rx->sdata->drop_unencrypted) &&
-		     (rx->sdata->eapol == 0 || !ieee80211_is_eapol(rx->skb)))) {
+		     (rx->sdata->eapol == 0 ||
+		      !ieee80211_is_eapol(rx->skb, hdrlen)))) {
 		if (net_ratelimit())
 			printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
 			       "encryption\n", rx->dev->name);
-		return TXRX_DROP;
+		return -EACCES;
 	}
-	return TXRX_CONTINUE;
+	return 0;
 }
 
-static ieee80211_txrx_result
-ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
+static int
+ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
 {
 	struct net_device *dev = rx->dev;
-	struct ieee80211_local *local = rx->local;
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 	u16 fc, hdrlen, ethertype;
 	u8 *payload;
 	u8 dst[ETH_ALEN];
 	u8 src[ETH_ALEN];
-	struct sk_buff *skb = rx->skb, *skb2;
+	struct sk_buff *skb = rx->skb;
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	DECLARE_MAC_BUF(mac);
 	DECLARE_MAC_BUF(mac2);
@@ -1031,11 +1027,9 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 	DECLARE_MAC_BUF(mac4);
 
 	fc = rx->fc;
-	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
-		return TXRX_CONTINUE;
 
 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
-		return TXRX_DROP;
+		return -1;
 
 	hdrlen = ieee80211_get_hdrlen(fc);
 
@@ -1064,7 +1058,7 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 				       print_mac(mac, hdr->addr1),
 				       print_mac(mac2, hdr->addr2),
 				       print_mac(mac3, hdr->addr3));
-			return TXRX_DROP;
+			return -1;
 		}
 		break;
 	case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
@@ -1081,7 +1075,7 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 				       print_mac(mac2, hdr->addr2),
 				       print_mac(mac3, hdr->addr3),
 				       print_mac(mac4, hdr->addr4));
-			return TXRX_DROP;
+			return -1;
 		}
 		break;
 	case IEEE80211_FCTL_FROMDS:
@@ -1092,7 +1086,7 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 		if (sdata->type != IEEE80211_IF_TYPE_STA ||
 		    (is_multicast_ether_addr(dst) &&
 		     !compare_ether_addr(src, dev->dev_addr)))
-			return TXRX_DROP;
+			return -1;
 		break;
 	case 0:
 		/* DA SA BSSID */
@@ -1108,21 +1102,20 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 				       print_mac(mac2, hdr->addr2),
 				       print_mac(mac3, hdr->addr3));
 			}
-			return TXRX_DROP;
+			return -1;
 		}
 		break;
 	}
 
-	payload = skb->data + hdrlen;
-
 	if (unlikely(skb->len - hdrlen < 8)) {
 		if (net_ratelimit()) {
 			printk(KERN_DEBUG "%s: RX too short data frame "
 			       "payload\n", dev->name);
 		}
-		return TXRX_DROP;
+		return -1;
 	}
 
+	payload = skb->data + hdrlen;
 	ethertype = (payload[6] << 8) | payload[7];
 
 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
@@ -1143,12 +1136,19 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 		memcpy(ehdr->h_source, src, ETH_ALEN);
 		ehdr->h_proto = len;
 	}
-	skb->dev = dev;
+	return 0;
+}
 
-	skb2 = NULL;
+static void
+ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
+{
+	struct net_device *dev = rx->dev;
+	struct ieee80211_local *local = rx->local;
+	struct sk_buff *skb, *xmit_skb;
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
-	dev->stats.rx_packets++;
-	dev->stats.rx_bytes += skb->len;
+	skb = rx->skb;
+	xmit_skb = NULL;
 
 	if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP
 	    || sdata->type == IEEE80211_IF_TYPE_VLAN) &&
@@ -1156,8 +1156,8 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 		if (is_multicast_ether_addr(skb->data)) {
 			/* send multicast frames both to higher layers in
 			 * local net stack and back to the wireless media */
-			skb2 = skb_copy(skb, GFP_ATOMIC);
-			if (!skb2 && net_ratelimit())
+			xmit_skb = skb_copy(skb, GFP_ATOMIC);
+			if (!xmit_skb && net_ratelimit())
 				printk(KERN_DEBUG "%s: failed to clone "
 				       "multicast frame\n", dev->name);
 		} else {
@@ -1172,7 +1172,7 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 				 * AP, so send the frame directly to it and
 				 * do not pass the frame to local net stack.
 				 */
-				skb2 = skb;
+				xmit_skb = skb;
 				skb = NULL;
 			}
 			if (dsta)
@@ -1187,13 +1187,45 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 		netif_rx(skb);
 	}
 
-	if (skb2) {
+	if (xmit_skb) {
 		/* send to wireless media */
-		skb2->protocol = __constant_htons(ETH_P_802_3);
-		skb_set_network_header(skb2, 0);
-		skb_set_mac_header(skb2, 0);
-		dev_queue_xmit(skb2);
+		xmit_skb->protocol = __constant_htons(ETH_P_802_3);
+		skb_set_network_header(xmit_skb, 0);
+		skb_set_mac_header(xmit_skb, 0);
+		dev_queue_xmit(xmit_skb);
 	}
+}
+
+static ieee80211_txrx_result
+ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
+{
+	struct net_device *dev = rx->dev;
+	u16 fc;
+	int err, hdrlen;
+
+	fc = rx->fc;
+	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
+		return TXRX_CONTINUE;
+
+	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
+		return TXRX_DROP;
+
+	hdrlen = ieee80211_get_hdrlen(fc);
+
+	if ((ieee80211_drop_802_1x_pae(rx, hdrlen)) ||
+	    (ieee80211_drop_unencrypted(rx, hdrlen)))
+		return TXRX_DROP;
+
+	err = ieee80211_data_to_8023(rx);
+	if (unlikely(err))
+		return TXRX_DROP;
+
+	rx->skb->dev = dev;
+
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += rx->skb->len;
+
+	ieee80211_deliver_skb(rx);
 
 	return TXRX_QUEUED;
 }
@@ -1347,8 +1379,6 @@ ieee80211_rx_handler ieee80211_rx_handlers[] =
 	 * are not passed to user space by these functions
 	 */
 	ieee80211_rx_h_remove_qos_control,
-	ieee80211_rx_h_802_1x_pae,
-	ieee80211_rx_h_drop_unencrypted,
 	ieee80211_rx_h_data,
 	ieee80211_rx_h_mgmt,
 	NULL

net/mac80211/tx.c

@@ -420,7 +420,6 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_txrx_data *tx)
 	return TXRX_CONTINUE;
 }
 
-
 static ieee80211_txrx_result
 ieee80211_tx_h_ps_buf(struct ieee80211_txrx_data *tx)
 {
@@ -433,13 +432,15 @@ ieee80211_tx_h_ps_buf(struct ieee80211_txrx_data *tx)
 		return ieee80211_tx_h_multicast_ps_buf(tx);
 }
 
-
-
-
 static ieee80211_txrx_result
 ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
 {
 	struct ieee80211_key *key;
+	const struct ieee80211_hdr *hdr;
+	u16 fc;
+
+	hdr = (const struct ieee80211_hdr *) tx->skb->data;
+	fc = le16_to_cpu(hdr->frame_control);
 
 	if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
 		tx->key = NULL;
@@ -448,7 +449,8 @@ ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
 	else if ((key = rcu_dereference(tx->sdata->default_key)))
 		tx->key = key;
 	else if (tx->sdata->drop_unencrypted &&
-		 !(tx->sdata->eapol && ieee80211_is_eapol(tx->skb))) {
+		 !(tx->sdata->eapol &&
+		   ieee80211_is_eapol(tx->skb, ieee80211_get_hdrlen(fc)))) {
 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
 		return TXRX_DROP;
 	} else {

net/mac80211/util.c

@@ -218,23 +218,11 @@ int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
 }
 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
 
-int ieee80211_is_eapol(const struct sk_buff *skb)
+int ieee80211_is_eapol(const struct sk_buff *skb, int hdrlen)
 {
-	const struct ieee80211_hdr *hdr;
-	u16 fc;
-	int hdrlen;
-
 	if (unlikely(skb->len < 10))
 		return 0;
 
-	hdr = (const struct ieee80211_hdr *) skb->data;
-	fc = le16_to_cpu(hdr->frame_control);
-
-	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
-		return 0;
-
-	hdrlen = ieee80211_get_hdrlen(fc);
-
 	if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) &&
 		     memcmp(skb->data + hdrlen, eapol_header,
 			    sizeof(eapol_header)) == 0))