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>

--
v2:
 - avoid the extra write to amsdu_hdr
 - avoid copy of asmdu_hdr into skb, use ptr instead
---
 net/mac80211/tx.c | 45 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 5023966..ebd2aa6 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3046,11 +3046,12 @@ static bool ieee80211_amsdu_prepare_head(struct 
ieee80211_sub_if_data *sdata,
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        struct ieee80211_hdr *hdr;
-       struct ethhdr amsdu_hdr;
+       struct ethhdr *amsdu_hdr;
        int hdr_len = fast_tx->hdr_len - sizeof(rfc1042_header);
        int subframe_len = skb->len - hdr_len;
        void *data;
        u8 *qc;
+       const u8 *src_addr, *dst_addr, *bssid;
 
        if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
                return false;
@@ -3058,19 +3059,45 @@ static bool ieee80211_amsdu_prepare_head(struct 
ieee80211_sub_if_data *sdata,
        if (info->control.flags & IEEE80211_TX_CTRL_AMSDU)
                return true;
 
-       if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(amsdu_hdr),
+       if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(*amsdu_hdr),
                                         &subframe_len))
                return false;
 
-       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);
+       data = skb_push(skb, sizeof(*amsdu_hdr));
+       memmove(data, data + sizeof(*amsdu_hdr), hdr_len);
+       hdr = data;
+       amsdu_hdr = data + hdr_len;
+
+       /* 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.
+        */
+       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;
+       }
+
+       if (bssid && ieee80211_has_fromds(hdr->frame_control))
+               src_addr = bssid;
+       else
+               src_addr = skb->data + fast_tx->sa_offs;
+
+       if (bssid && ieee80211_has_tods(hdr->frame_control))
+               dst_addr = bssid;
+       else
+               dst_addr = skb->data + fast_tx->da_offs;
 
-       data = skb_push(skb, sizeof(amsdu_hdr));
-       memmove(data, data + sizeof(amsdu_hdr), hdr_len);
-       memcpy(data + hdr_len, &amsdu_hdr, sizeof(amsdu_hdr));
+       amsdu_hdr->h_proto = cpu_to_be16(subframe_len);
+       memcpy(amsdu_hdr->h_source, src_addr, ETH_ALEN);
+       memcpy(amsdu_hdr->h_dest, dst_addr, ETH_ALEN);
 
-       hdr = data;
        qc = ieee80211_get_qos_ctl(hdr);
        *qc |= IEEE80211_QOS_CTL_A_MSDU_PRESENT;
 
-- 
2.1.4

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