Commit ed92a9b5 authored Mar 16, 2017 by Masashi Honma Committed by Johannes Berg Mar 29, 2017

mac80211: mesh: drop new node with weak power



On some practical cases, it is useful to drop new node in the distance.
Because mesh metric is calculated with hop count and without RSSI
information, a node far from local peer and near to destination node
could be used as best path.

For example, the nodes are located in linear. Distance of 0 - 1 and
1 - 2 and 2 - 3 is 20meters. 0 to 3 signal is very weak.

    0 --- 1 --- 2 --- 3

Though most robust path from 0 to 3 is 0 -> 1 -> 2 -> 3,
unfortunately, node 0 could recognize node 3 as neighbor. Then node 3
could be next of node 0. This patch aims to avoid such a case.

[Johannes:]
Dropping the node entirely isn't ideal, but at least with encryption
there will be a limit on # of keys the hardware can deal with, and
there might also be a limit on the number of stations it supports.

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

parent b6ecfd46

net/mac80211/mesh.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -1100,8 +1100,14 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
		if (!channel \|\| channel->flags & IEEE80211_CHAN_DISABLED)
		return;

		if (mesh_matches_local(sdata, &elems))
		if (mesh_matches_local(sdata, &elems)) {
		mpl_dbg(sdata, "rssi_threshold=%d,rx_status->signal=%d\n",
		sdata->u.mesh.mshcfg.rssi_threshold, rx_status->signal);
		if (!sdata->u.mesh.user_mpm \|\|
		sdata->u.mesh.mshcfg.rssi_threshold == 0 \|\|
		sdata->u.mesh.mshcfg.rssi_threshold < rx_status->signal)
		mesh_neighbour_update(sdata, mgmt->sa, &elems);
		}

		if (ifmsh->sync_ops)
		ifmsh->sync_ops->rx_bcn_presp(sdata,

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