7 files changed, 39 insertions, 1 deletions

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index be35a68746a7..38fda5ee57f5 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -2112,6 +2112,10 @@ enum nl80211_mntr_flags {
  * @NL80211_MESHCONF_FORWARDING: set Mesh STA as forwarding or non-forwarding
  * or forwarding entity (default is TRUE - forwarding entity)
  *
+ * @NL80211_MESHCONF_RSSI_THRESHOLD: RSSI threshold in dBm. This specifies the
+ * threshold for average signal strength of candidate station to establish
+ * a peer link.
+ *
  * @NL80211_MESHCONF_ATTR_MAX: highest possible mesh configuration attribute
  *
  * @__NL80211_MESHCONF_ATTR_AFTER_LAST: internal use
@@ -2137,6 +2141,7 @@ enum nl80211_meshconf_params {
         NL80211_MESHCONF_GATE_ANNOUNCEMENTS,
         NL80211_MESHCONF_HWMP_PERR_MIN_INTERVAL,
         NL80211_MESHCONF_FORWARDING,
+        NL80211_MESHCONF_RSSI_THRESHOLD,
 
         /* keep last */
         __NL80211_MESHCONF_ATTR_AFTER_LAST,
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 0178c7489373..b4e015c90885 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -809,6 +809,7 @@ struct mesh_config {
          * Still keeping the same nomenclature to be in sync with the spec. */
         bool  dot11MeshGateAnnouncementProtocol;
         bool dot11MeshForwarding;
+        s32 rssi_threshold;
 };
 
 /**
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 6a77d4c910f9..ab31cc56a2fb 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1314,6 +1314,14 @@ static int ieee80211_update_mesh_config(struct wiphy *wiphy,
         }
         if (_chg_mesh_attr(NL80211_MESHCONF_FORWARDING, mask))
                 conf->dot11MeshForwarding = nconf->dot11MeshForwarding;
+        if (_chg_mesh_attr(NL80211_MESHCONF_RSSI_THRESHOLD, mask)) {
+                /* our RSSI threshold implementation is supported only for
+                 * devices that report signal in dBm.
+                 */
+                if (!(sdata->local->hw.flags & IEEE80211_HW_SIGNAL_DBM))
+                        return -ENOTSUPP;
+                conf->rssi_threshold = nconf->rssi_threshold;
+        }
         return 0;
 }
 
diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index 510ed1dab3c7..9f484d8905fd 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -443,6 +443,7 @@ IEEE80211_IF_FILE(dot11MeshGateAnnouncementProtocol,
 IEEE80211_IF_FILE(dot11MeshHWMPRannInterval,
                 u.mesh.mshcfg.dot11MeshHWMPRannInterval, DEC);
 IEEE80211_IF_FILE(dot11MeshForwarding, u.mesh.mshcfg.dot11MeshForwarding, DEC);
+IEEE80211_IF_FILE(rssi_threshold, u.mesh.mshcfg.rssi_threshold, DEC);
 #endif
 
 
@@ -581,6 +582,7 @@ static void add_mesh_config(struct ieee80211_sub_if_data *sdata)
         MESHPARAMS_ADD(dot11MeshHWMPRootMode);
         MESHPARAMS_ADD(dot11MeshHWMPRannInterval);
         MESHPARAMS_ADD(dot11MeshGateAnnouncementProtocol);
+        MESHPARAMS_ADD(rssi_threshold);
 #undef MESHPARAMS_ADD
 }
 #endif
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index 8806e5ef8ffe..80ce52772538 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -31,6 +31,11 @@
 #define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
 #define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
 
+#define sta_meets_rssi_threshold(sta, sdata) \
+                (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
+                (s8) -ewma_read(&sta->avg_signal) > \
+                sdata->u.mesh.mshcfg.rssi_threshold)
+
 enum plink_event {
         PLINK_UNDEFINED,
         OPN_ACPT,
@@ -301,7 +306,8 @@ void mesh_neighbour_update(u8 *hw_addr, u32 rates,
         if (mesh_peer_accepts_plinks(elems) &&
                         sta->plink_state == NL80211_PLINK_LISTEN &&
                         sdata->u.mesh.accepting_plinks &&
-                        sdata->u.mesh.mshcfg.auto_open_plinks)
+                        sdata->u.mesh.mshcfg.auto_open_plinks &&
+                        sta_meets_rssi_threshold(sta, sdata))
                 mesh_plink_open(sta);
 
         rcu_read_unlock();
@@ -531,6 +537,14 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
                 return;
         }
 
+        if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
+            !sta_meets_rssi_threshold(sta, sdata)) {
+                mpl_dbg("Mesh plink: %pM does not meet rssi threshold\n",
+                        sta->sta.addr);
+                rcu_read_unlock();
+                return;
+        }
+
         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
                 mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
                 rcu_read_unlock();
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;