Problem: When injecting an A-MSDU using a PF_PACKET socket, the qos flag IEEE80211_QOS_CTL_A_MSDU_PRESENT is cleared. How to reproduce: Inject a frame on a mac80211 hwsim monitor interface and have tshark sniffing on this monitor interface. You'll see the packet twice: Once with correct flag and once with flag cleared. On hwsim0, you'll only see the packet with a cleared flag. Signed-off-by: Michael Braun <michael-dev@xxxxxxxxxxxxx> --- net/mac80211/wme.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c index 9eb0aee..f6a708c 100644 --- a/net/mac80211/wme.c +++ b/net/mac80211/wme.c @@ -248,6 +248,11 @@ void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata, /* preserve EOSP bit */ ack_policy = *p & IEEE80211_QOS_CTL_EOSP; + /* preserve A-MSDU bit for MONITOR interfaces to allow injecting + * A-MSDU frames + */ + ack_policy |= *p & IEEE80211_QOS_CTL_A_MSDU_PRESENT; + if (is_multicast_ether_addr(hdr->addr1) || sdata->noack_map & BIT(tid)) { ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK; -- 2.1.4