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>

4 files changed, 86 insertions, 66 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index e9109443cb1..e2aed0b2d8b 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/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,
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index a26aa7f5049..478d85563bd 100644
--- a/net/mac80211/rx.c
+++ b/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
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 50ab4b2de1e..12c15588af6 100644
--- a/net/mac80211/tx.c
+++ b/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 {
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 88f262baaa5..5227c16f113 100644
--- a/net/mac80211/util.c
+++ b/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))