Commit a0dc0203 authored Jan 17, 2019 by Bob Copeland Committed by Johannes Berg Jan 19, 2019

mac80211: fix miscounting of ttl-dropped frames



In ieee80211_rx_h_mesh_fwding, we increment the 'dropped_frames_ttl'
counter when we decrement the ttl to zero.  For unicast frames
destined for other hosts, we stop processing the frame at that point.

For multicast frames, we do not rebroadcast it in this case, but we
do pass the frame up the stack to process it on this STA.  That
doesn't match the usual definition of "dropped," so don't count
those as such.

With this change, something like `ping6 -i0.2 ff02::1%mesh0` from a
peer in a ttl=1 network no longer increments the counter rapidly.

Signed-off-by: Bob Copeland <bobcopeland@fb.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

parent 9c5d3afa

net/mac80211/rx.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -2723,7 +2723,9 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
		skb_set_queue_mapping(skb, q);

		if (!--mesh_hdr->ttl) {
		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
		if (!is_multicast_ether_addr(hdr->addr1))
		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh,
		dropped_frames_ttl);
		goto out;
		}

Admin message