commit 3f718fd8401d7db86b9efc3ea1cdf5df41354b9f
author Chun-Yeow Yeoh <yeohchunyeow@gmail.com> Fri Nov 08 15:09:43 2013 +0800
committer Johannes Berg <johannes.berg@intel.com> Mon Nov 25 16:50:13 2013 +0100
tree 62221339cdbf9612427669850a7d1429e982e2d0
parent 051a41fa4ee14f5c39668f0980973b9a195de560

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>

net/mac80211/cfg.c

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 9e7e68d..364ce0c 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3119,9 +3119,17 @@
 		    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:

net/mac80211/ieee80211_i.h

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 29dc505..4aea4e7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1228,6 +1228,7 @@
 	u8 mode;
 	u8 count;
 	u8 ttl;
+	u16 pre_value;
 };
 
 /* Parsed Information Elements */

net/mac80211/mesh.c

diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 896fe3b..ba10525 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -943,14 +943,19 @@
 		 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 @@
 	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 @@
 	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 @@
 			   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);

net/mac80211/spectmgmt.c

diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c
index a40da20..6ab0090 100644
--- a/net/mac80211/spectmgmt.c
+++ b/net/mac80211/spectmgmt.c
@@ -78,6 +78,8 @@
 	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);

net/mac80211/util.c

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index e9ce36d..9f9b9bd 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2457,14 +2457,9 @@
 			  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);