mac80211: clean up eapol frame handling/port control

This cleans up the eapol frame handling and some related code in the
receive and transmit paths. After this patch
 * EAPOL frames addressed to us or the EAPOL group address are
   always accepted regardless of whether they are encrypted or not
 * other frames from a station are dropped if PAE is enabled and
   the station is not authorized
 * unencrypted frames (except the EAPOL frames above) are dropped if
   drop_unencrypted is enabled
 * some superfluous code that eth_type_trans handles anyway is gone
 * port control is done for transmitted packets

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

1 files changed, 68 insertions, 65 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index e65da5780cd3..505159f8dffc 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -208,7 +208,7 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
                 rthdr->it_len = cpu_to_le16(rtap_len);
         }
 
-        skb_set_mac_header(skb, 0);
+        skb_reset_mac_header(skb);
         skb->ip_summed = CHECKSUM_UNNECESSARY;
         skb->pkt_type = PACKET_OTHERHOST;
         skb->protocol = htons(ETH_P_802_2);
@@ -405,18 +405,6 @@ ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
                 return TXRX_DROP;
         }
 
-        if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
-                rx->skb->pkt_type = PACKET_OTHERHOST;
-        else if (compare_ether_addr(rx->dev->dev_addr, hdr->addr1) == 0)
-                rx->skb->pkt_type = PACKET_HOST;
-        else if (is_multicast_ether_addr(hdr->addr1)) {
-                if (is_broadcast_ether_addr(hdr->addr1))
-                        rx->skb->pkt_type = PACKET_BROADCAST;
-                else
-                        rx->skb->pkt_type = PACKET_MULTICAST;
-        } else
-                rx->skb->pkt_type = PACKET_OTHERHOST;
-
         /* Drop disallowed frame classes based on STA auth/assoc state;
          * IEEE 802.11, Chap 5.5.
          *
@@ -990,18 +978,10 @@ ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
 }
 
 static int
-ieee80211_drop_802_1x_pae(struct ieee80211_txrx_data *rx, int hdrlen)
+ieee80211_802_1x_port_control(struct ieee80211_txrx_data *rx)
 {
-        if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb, hdrlen) &&
-            rx->sdata->type != IEEE80211_IF_TYPE_STA &&
-            (rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
-                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, hdrlen))) {
+        if (unlikely(rx->sdata->ieee802_1x_pac &&
+                     (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)))) {
 #ifdef CONFIG_MAC80211_DEBUG
                 printk(KERN_DEBUG "%s: dropped frame "
                        "(unauthorized port)\n", rx->dev->name);
@@ -1013,7 +993,7 @@ ieee80211_drop_802_1x_pae(struct ieee80211_txrx_data *rx, int hdrlen)
 }
 
 static int
-ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx, int hdrlen)
+ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx)
 {
         /*
          * Pass through unencrypted frames if the hardware has
@@ -1026,9 +1006,7 @@ ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx, int hdrlen)
         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, hdrlen)))) {
+                     (rx->key || rx->sdata->drop_unencrypted))) {
                 if (net_ratelimit())
                         printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
                                "encryption\n", rx->dev->name);
@@ -1156,6 +1134,7 @@ ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
         } else {
                 struct ethhdr *ehdr;
                 __be16 len;
+
                 skb_pull(skb, hdrlen);
                 len = htons(skb->len);
                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
@@ -1166,6 +1145,34 @@ ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
         return 0;
 }
 
+/*
+ * requires that rx->skb is a frame with ethernet header
+ */
+static bool ieee80211_frame_allowed(struct ieee80211_txrx_data *rx)
+{
+        static const u8 pae_group_addr[ETH_ALEN]
+                = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
+        struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
+
+        /*
+         * Allow EAPOL frames to us/the PAE group address regardless
+         * of whether the frame was encrypted or not.
+         */
+        if (ehdr->h_proto == htons(ETH_P_PAE) &&
+            (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
+             compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
+                return true;
+
+        if (ieee80211_802_1x_port_control(rx) ||
+            ieee80211_drop_unencrypted(rx))
+                return false;
+
+        return true;
+}
+
+/*
+ * requires that rx->skb is a frame with ethernet header
+ */
 static void
 ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
 {
@@ -1173,31 +1180,32 @@ ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
         struct ieee80211_local *local = rx->local;
         struct sk_buff *skb, *xmit_skb;
         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+        struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
+        struct sta_info *dsta;
 
         skb = rx->skb;
         xmit_skb = NULL;
 
-        if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP
-            || sdata->type == IEEE80211_IF_TYPE_VLAN) &&
+        if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP ||
+                                      sdata->type == IEEE80211_IF_TYPE_VLAN) &&
             (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
-                if (is_multicast_ether_addr(skb->data)) {
-                        /* send multicast frames both to higher layers in
-                         * local net stack and back to the wireless media */
+                if (is_multicast_ether_addr(ehdr->h_dest)) {
+                        /*
+                         * send multicast frames both to higher layers in
+                         * local net stack and back to the wireless medium
+                         */
                         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 {
-                        struct sta_info *dsta;
                         dsta = sta_info_get(local, skb->data);
-                        if (dsta && !dsta->dev) {
-                                if (net_ratelimit())
-                                        printk(KERN_DEBUG "Station with null "
-                                               "dev structure!\n");
-                        } else if (dsta && dsta->dev == dev) {
-                                /* Destination station is associated to this
-                                 * AP, so send the frame directly to it and
-                                 * do not pass the frame to local net stack.
+                        if (dsta && dsta->dev == dev) {
+                                /*
+                                 * The destination station is associated to
+                                 * this AP (in this VLAN), so send the frame
+                                 * directly to it and do not pass it to local
+                                 * net stack.
                                  */
                                 xmit_skb = skb;
                                 skb = NULL;
@@ -1217,8 +1225,8 @@ ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
         if (xmit_skb) {
                 /* send to wireless media */
                 xmit_skb->protocol = htons(ETH_P_802_3);
-                skb_set_network_header(xmit_skb, 0);
-                skb_set_mac_header(xmit_skb, 0);
+                skb_reset_network_header(xmit_skb);
+                skb_reset_mac_header(xmit_skb);
                 dev_queue_xmit(xmit_skb);
         }
 }
@@ -1303,38 +1311,36 @@ ieee80211_rx_h_amsdu(struct ieee80211_txrx_data *rx)
                         }
                 }
 
-                skb_set_network_header(frame, 0);
+                skb_reset_network_header(frame);
                 frame->dev = dev;
                 frame->priority = skb->priority;
                 rx->skb = frame;
 
-                if ((ieee80211_drop_802_1x_pae(rx, 0)) ||
-                    (ieee80211_drop_unencrypted(rx, 0))) {
-                        if (skb == frame) /* last frame */
-                                return TXRX_DROP;
-                        dev_kfree_skb(frame);
-                        continue;
-                }
-
                 payload = frame->data;
                 ethertype = (payload[6] << 8) | payload[7];
 
                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
-                        ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
-                        compare_ether_addr(payload,
-                                           bridge_tunnel_header) == 0)) {
+                            ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
+                           compare_ether_addr(payload,
+                                              bridge_tunnel_header) == 0)) {
                         /* remove RFC1042 or Bridge-Tunnel
                          * encapsulation and replace EtherType */
                         skb_pull(frame, 6);
                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
                 } else {
-                        memcpy(skb_push(frame, sizeof(__be16)), &len,
-                                sizeof(__be16));
+                        memcpy(skb_push(frame, sizeof(__be16)),
+                               &len, sizeof(__be16));
                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
                 }
 
+                if (!ieee80211_frame_allowed(rx)) {
+                        if (skb == frame) /* last frame */
+                                return TXRX_DROP;
+                        dev_kfree_skb(frame);
+                        continue;
+                }
 
                 ieee80211_deliver_skb(rx);
         }
@@ -1347,7 +1353,7 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
 {
         struct net_device *dev = rx->dev;
         u16 fc;
-        int err, hdrlen;
+        int err;
 
         fc = rx->fc;
         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
@@ -1356,16 +1362,13 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
         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;
 
+        if (!ieee80211_frame_allowed(rx))
+                return TXRX_DROP;
+
         rx->skb->dev = dev;
 
         dev->stats.rx_packets++;