{nl,cfg,mac}80211: Implement RSSI threshold for mesh peering

Mesh peer links are established only if average rssi of the peer
candidate satisfies the threshold. This is not in 802.11s specification
but was requested by David Fulgham, an open80211s user. This is a way to avoid
marginal peer links with stations that are barely within range.

This patch adds a new mesh configuration parameter, mesh_rssi_threshold. This
feature is supported only for hardwares that report signal in dBm.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 8 insertions, 0 deletions

diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index 9d3e3b6bfcf4..ba21ab22187b 100644
--- a/net/wireless/mesh.c
+++ b/net/wireless/mesh.c
@@ -23,6 +23,8 @@
 #define MESH_PERR_MIN_INT       100
 #define MESH_DIAM_TRAVERSAL_TIME 50
 
+#define MESH_RSSI_THRESHOLD     0
+
 /*
  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
  * before timing out.  This way it will remain ACTIVE and no data frames
@@ -56,6 +58,7 @@ const struct mesh_config default_mesh_config = {
         .dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
         .dot11MeshGateAnnouncementProtocol = false,
         .dot11MeshForwarding = true,
+        .rssi_threshold = MESH_RSSI_THRESHOLD,
 };
 
 const struct mesh_setup default_mesh_setup = {
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 1998c3682774..25a470abd21d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3290,6 +3290,8 @@ static int nl80211_get_mesh_config(struct sk_buff *skb,
                         cur_params.dot11MeshGateAnnouncementProtocol);
         NLA_PUT_U8(msg, NL80211_MESHCONF_FORWARDING,
                         cur_params.dot11MeshForwarding);
+        NLA_PUT_U32(msg, NL80211_MESHCONF_RSSI_THRESHOLD,
+                        cur_params.rssi_threshold);
         nla_nest_end(msg, pinfoattr);
         genlmsg_end(msg, hdr);
         return genlmsg_reply(msg, info);
@@ -3322,6 +3324,7 @@ static const struct nla_policy nl80211_meshconf_params_policy[NL80211_MESHCONF_A
         [NL80211_MESHCONF_HWMP_RANN_INTERVAL] = { .type = NLA_U16 },
         [NL80211_MESHCONF_GATE_ANNOUNCEMENTS] = { .type = NLA_U8 },
         [NL80211_MESHCONF_FORWARDING] = { .type = NLA_U8 },
+        [NL80211_MESHCONF_RSSI_THRESHOLD] = { .type = NLA_U32},
 };
 
 static const struct nla_policy
@@ -3413,6 +3416,8 @@ do {\
                         nla_get_u8);
         FILL_IN_MESH_PARAM_IF_SET(tb, cfg, dot11MeshForwarding,
                         mask, NL80211_MESHCONF_FORWARDING, nla_get_u8);
+        FILL_IN_MESH_PARAM_IF_SET(tb, cfg, rssi_threshold,
+                        mask, NL80211_MESHCONF_RSSI_THRESHOLD, nla_get_u32);
         if (mask_out)
                 *mask_out = mask;