[PATCH] mac80211: fix A-MSDU outer SA/DA

[Michael Braun]

According to IEEE 802.11-2012 section 8.3.2 table 8-19, the outer SA/DA
of A-MSDU frames need to be changed depending on FromDS/ToDS values.

Signed-off-by: Michael Braun <michael-...@fami-braun.de>
---
 net/mac80211/tx.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 5023966..acd334c 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3050,7 +3050,7 @@ static bool ieee80211_amsdu_prepare_head(struct 
ieee80211_sub_if_data *sdata,
        int hdr_len = fast_tx->hdr_len - sizeof(rfc1042_header);
        int subframe_len = skb->len - hdr_len;
        void *data;
-       u8 *qc;
+       u8 *qc, *bssid;
 
        if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
                return false;
@@ -3062,10 +3062,32 @@ static bool ieee80211_amsdu_prepare_head(struct 
ieee80211_sub_if_data *sdata,
                                         &subframe_len))
                return false;
 
+       switch (sdata->vif.type) {
+       case NL80211_IFTYPE_STATION:
+               bssid = sdata->u.mgd.bssid;
+               break;
+       case NL80211_IFTYPE_AP:
+       case NL80211_IFTYPE_AP_VLAN:
+               bssid = sdata->vif.addr;
+               break;
+       default:
+               bssid = NULL;
+       }
+
        amsdu_hdr.h_proto = cpu_to_be16(subframe_len);
        memcpy(amsdu_hdr.h_source, skb->data + fast_tx->sa_offs, ETH_ALEN);
        memcpy(amsdu_hdr.h_dest, skb->data + fast_tx->da_offs, ETH_ALEN);
 
+       /* according to IEEE 802.11-2012 8.3.2 table 8-19, the outer SA/DA
+        * fields needs to be changed to BSSID for A-MSDU frames depending
+        * on FromDS/ToDS values.
+        */
+       hdr = data;
+       if (bssid && ieee80211_has_fromds(hdr->frame_control))
+               memcpy(amsdu_hdr.h_source, bssid, ETH_ALEN);
+       if (bssid && ieee80211_has_tods(hdr->frame_control))
+               memcpy(amsdu_hdr.h_dest, bssid, ETH_ALEN);
+
        data = skb_push(skb, sizeof(amsdu_hdr));
        memmove(data, data + sizeof(amsdu_hdr), hdr_len);
        memcpy(data + hdr_len, &amsdu_hdr, sizeof(amsdu_hdr));
-- 
2.1.4