Commit 92c4dca6 authored by Johannes Berg's avatar Johannes Berg Committed by Luca Coelho

iwlwifi: mvm: fix deduplication start logic

If the first frame on a given TID is received with seqno 0 and needed
to be retransmitted, we erroneously drop it because the deduplication
data is initialized to zero, and then comparing

        if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
                     dup_data->last_seq[tid] == hdr->seq_ctrl &&
                     dup_data->last_sub_frame[tid] >= sub_frame_idx))
                return true;

will return in iwl_mvm_is_dup() since last_sub_frame is also set to
zero, and sub_frame_idx is usually zero since this only covers the
relatively rare case of A-MSDU.

Fix this by initializing the last_seq array to 0xffff, which is an
impossible value for hdr->seq_ctrl to have here because the lower
four bits are the fragment number, and fragments aren't handled in
this code but go to mac80211 instead.

Fixes: a571f5f6 ("iwlwifi: mvm: add duplicate packet detection per rx queue")
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
parent b092c9f2
......@@ -1402,11 +1402,24 @@ int iwl_mvm_add_sta(struct iwl_mvm *mvm,
if (iwl_mvm_has_new_rx_api(mvm) &&
!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) {
int q;
dup_data = kcalloc(mvm->trans->num_rx_queues,
sizeof(*dup_data),
GFP_KERNEL);
sizeof(*dup_data), GFP_KERNEL);
if (!dup_data)
return -ENOMEM;
/*
* Initialize all the last_seq values to 0xffff which can never
* compare equal to the frame's seq_ctrl in the check in
* iwl_mvm_is_dup() since the lower 4 bits are the fragment
* number and fragmented packets don't reach that function.
*
* This thus allows receiving a packet with seqno 0 and the
* retry bit set as the very first packet on a new TID.
*/
for (q = 0; q < mvm->trans->num_rx_queues; q++)
memset(dup_data[q].last_seq, 0xff,
sizeof(dup_data[q].last_seq));
mvm_sta->dup_data = dup_data;
}
......
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