mac80211: Fill in skb->protocol information for injected frames

Some drivers (ath9k for example) are using skb->protocol to treat EAPOL
frames somehow special (disallow aggregation for example).

When running in AP mode hostapd injects the EAPOL frames through a
monitor interface and thus skb->protocol isn't set at all. Hence, if the
injected frame is a data frame and carries a rfc1042 headaer update the
skb->protocol field accordingly.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 8cb0d2d0ac69..69fd494f32f9 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1608,7 +1608,9 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
         struct ieee80211_radiotap_header *prthdr =
                 (struct ieee80211_radiotap_header *)skb->data;
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+        struct ieee80211_hdr *hdr;
         u16 len_rthdr;
+        u8 *payload;
 
         /*
          * Frame injection is not allowed if beaconing is not allowed
@@ -1659,6 +1661,24 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
         skb_set_network_header(skb, len_rthdr);
         skb_set_transport_header(skb, len_rthdr);
 
+        /*
+         * Initialize skb->protocol if the injected frame is a data frame
+         * carrying a rfc1042 header
+         */
+        if (skb->len > len_rthdr + 2) {
+                hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
+                if (ieee80211_is_data(hdr->frame_control) &&
+                    skb->len >= len_rthdr +
+                                ieee80211_hdrlen(hdr->frame_control) +
+                                sizeof(rfc1042_header) + 2) {
+                        payload = (u8 *)hdr +
+                                  ieee80211_hdrlen(hdr->frame_control);
+                        if (compare_ether_addr(payload, rfc1042_header) == 0)
+                                skb->protocol = cpu_to_be16((payload[6] << 8) |
+                                                            payload[7]);
+                }
+        }
+
         memset(info, 0, sizeof(*info));
 
         info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;