mac80211: fix the mesh channel switch support

Mesh STA receiving the mesh CSA action frame is not able to trigger
the mesh channel switch due to the incorrect handling and comparison
of mesh channel switch parameters element (MCSP)'s TTL. Make sure
the MCSP's TTL is updated accordingly before calling the
ieee80211_mesh_process_chnswitch. Also, we update the beacon before
forwarding the CSA action frame, so MCSP's precedence value and
initiator flag need to be updated prior to this.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 9e7e68d7b1a7c4b1e933ff35bb939407e54aba9d..364ce0c5962fd48c85ea23b71b2d1dd463082575 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3119,9 +3119,17 @@ static int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
                    params->chandef.chan->band)
                        return -EINVAL;
 
+               ifmsh->chsw_init = true;
+               if (!ifmsh->pre_value)
+                       ifmsh->pre_value = 1;
+               else
+                       ifmsh->pre_value++;
+
                err = ieee80211_mesh_csa_beacon(sdata, params, true);
-               if (err < 0)
+               if (err < 0) {
+                       ifmsh->chsw_init = false;
                        return err;
+               }
                break;
 #endif
        default:

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 29dc505be125c3c19737f8f6cee911492c52727c..4aea4e7911135133818e66a1439b111d14e6147e 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1228,6 +1228,7 @@ struct ieee80211_csa_ie {
        u8 mode;
        u8 count;
        u8 ttl;
+       u16 pre_value;
 };
 
 /* Parsed Information Elements */

diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 896fe3bd599e9bedd5db13dbc8ed04ab76e5bd88..ba105257d03f1cffc4398f42c52e67b1e8d3eaaa 100644 (file)
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -943,14 +943,19 @@ ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
                 params.chandef.chan->center_freq);
 
        params.block_tx = csa_ie.mode & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT;
-       if (beacon)
+       if (beacon) {
                ifmsh->chsw_ttl = csa_ie.ttl - 1;
-       else
-               ifmsh->chsw_ttl = 0;
+               if (ifmsh->pre_value >= csa_ie.pre_value)
+                       return false;
+               ifmsh->pre_value = csa_ie.pre_value;
+       }
 
-       if (ifmsh->chsw_ttl > 0)
+       if (ifmsh->chsw_ttl < ifmsh->mshcfg.dot11MeshTTL) {
                if (ieee80211_mesh_csa_beacon(sdata, &params, false) < 0)
                        return false;
+       } else {
+               return false;
+       }
 
        sdata->csa_radar_required = params.radar_required;
 
@@ -1163,7 +1168,6 @@ static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata,
        offset_ttl = (len < 42) ? 7 : 10;
        *(pos + offset_ttl) -= 1;
        *(pos + offset_ttl + 1) &= ~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
-       sdata->u.mesh.chsw_ttl = *(pos + offset_ttl);
 
        memcpy(mgmt_fwd, mgmt, len);
        eth_broadcast_addr(mgmt_fwd->da);
@@ -1182,7 +1186,7 @@ static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
        u16 pre_value;
        bool fwd_csa = true;
        size_t baselen;
-       u8 *pos, ttl;
+       u8 *pos;
 
        if (mgmt->u.action.u.measurement.action_code !=
            WLAN_ACTION_SPCT_CHL_SWITCH)
@@ -1193,8 +1197,8 @@ static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
                           u.action.u.chan_switch.variable);
        ieee802_11_parse_elems(pos, len - baselen, false, &elems);
 
-       ttl = elems.mesh_chansw_params_ie->mesh_ttl;
-       if (!--ttl)
+       ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
+       if (!--ifmsh->chsw_ttl)
                fwd_csa = false;
 
        pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value);

diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c
index a40da20b32e074a3923f844edf104eca33a6134c..6ab00907008461fb14d551b2633a8dbcd4fef623 100644 (file)
--- a/net/mac80211/spectmgmt.c
+++ b/net/mac80211/spectmgmt.c
@@ -78,6 +78,8 @@ int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
        if (elems->mesh_chansw_params_ie) {
                csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
                csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
+               csa_ie->pre_value = le16_to_cpu(
+                               elems->mesh_chansw_params_ie->mesh_pre_value);
        }
 
        new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index e9ce36d32ef5d464664926127f4aec4244fb7307..9f9b9bd3fd44798e7030fb3a44c46da962cfd7ba 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2457,14 +2457,9 @@ int ieee80211_send_action_csa(struct ieee80211_sub_if_data *sdata,
                          WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
                put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos); /* Reason Cd */
                pos += 2;
-               if (!ifmsh->pre_value)
-                       ifmsh->pre_value = 1;
-               else
-                       ifmsh->pre_value++;
                pre_value = cpu_to_le16(ifmsh->pre_value);
                memcpy(pos, &pre_value, 2);             /* Precedence Value */
                pos += 2;
-               ifmsh->chsw_init = true;
        }
 
        ieee80211_tx_skb(sdata, skb);