mac80211: mesh: clean up rx_bcn_presp API

We currently pass the entire elements to the rx_bcn_presp()
method, but only need mesh_config. Additionally, we use the
length of the elements to calculate back the entire frame's
length, but that's confusing - just pass the length of the
frame instead.

Link: https://lore.kernel.org/r/20210920154009.a18ed3d2da6c.I1824b773a0fbae4453e1433c184678ca14e8df45@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/ieee80211_i.h

@@ -631,10 +631,9 @@ struct ieee80211_if_ocb {
  */
 struct ieee802_11_elems;
 struct ieee80211_mesh_sync_ops {
-	void (*rx_bcn_presp)(struct ieee80211_sub_if_data *sdata,
-			     u16 stype,
-			     struct ieee80211_mgmt *mgmt,
-			     struct ieee802_11_elems *elems,
+	void (*rx_bcn_presp)(struct ieee80211_sub_if_data *sdata, u16 stype,
+			     struct ieee80211_mgmt *mgmt, unsigned int len,
+			     const struct ieee80211_meshconf_ie *mesh_cfg,
 			     struct ieee80211_rx_status *rx_status);
 
 	/* should be called with beacon_data under RCU read lock */

net/mac80211/mesh.c

@@ -1353,8 +1353,8 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 	}
 
 	if (ifmsh->sync_ops)
-		ifmsh->sync_ops->rx_bcn_presp(sdata,
-			stype, mgmt, &elems, rx_status);
+		ifmsh->sync_ops->rx_bcn_presp(sdata, stype, mgmt, len,
+					      elems.mesh_config, rx_status);
 }
 
 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)

net/mac80211/mesh_sync.c

@@ -3,6 +3,7 @@
  * Copyright 2011-2012, Pavel Zubarev <pavel.zubarev@gmail.com>
  * Copyright 2011-2012, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
  * Copyright 2011-2012, cozybit Inc.
+ * Copyright (C) 2021 Intel Corporation
  */
 
 #include "ieee80211_i.h"
@@ -35,12 +36,12 @@ struct sync_method {
 /**
  * mesh_peer_tbtt_adjusting - check if an mp is currently adjusting its TBTT
  *
- * @ie: information elements of a management frame from the mesh peer
+ * @cfg: mesh config element from the mesh peer (or %NULL)
  */
-static bool mesh_peer_tbtt_adjusting(struct ieee802_11_elems *ie)
+static bool mesh_peer_tbtt_adjusting(const struct ieee80211_meshconf_ie *cfg)
 {
-	return (ie->mesh_config->meshconf_cap &
-			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING) != 0;
+	return cfg &&
+	       (cfg->meshconf_cap & IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING);
 }
 
 void mesh_sync_adjust_tsf(struct ieee80211_sub_if_data *sdata)
@@ -76,11 +77,11 @@ void mesh_sync_adjust_tsf(struct ieee80211_sub_if_data *sdata)
 	}
 }
 
-static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
-				   u16 stype,
-				   struct ieee80211_mgmt *mgmt,
-				   struct ieee802_11_elems *elems,
-				   struct ieee80211_rx_status *rx_status)
+static void
+mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata, u16 stype,
+			      struct ieee80211_mgmt *mgmt, unsigned int len,
+			      const struct ieee80211_meshconf_ie *mesh_cfg,
+			      struct ieee80211_rx_status *rx_status)
 {
 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 	struct ieee80211_local *local = sdata->local;
@@ -101,10 +102,7 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 	 */
 	if (ieee80211_have_rx_timestamp(rx_status))
 		t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
-						       24 + 12 +
-						       elems->total_len +
-						       FCS_LEN,
-						       24);
+						       len + FCS_LEN, 24);
 	else
 		t_r = drv_get_tsf(local, sdata);
 
@@ -119,7 +117,7 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 	 * dot11MeshNbrOffsetMaxNeighbor non-peer non-MBSS neighbors
 	 */
 
-	if (elems->mesh_config && mesh_peer_tbtt_adjusting(elems)) {
+	if (mesh_peer_tbtt_adjusting(mesh_cfg)) {
 		msync_dbg(sdata, "STA %pM : is adjusting TBTT\n",
 			  sta->sta.addr);
 		goto no_sync;