wifi: mac80211: fix multi-BSSID element parsing

When parsing a frame containing a multi-BSSID element, we
need to know both the transmitted and non-transmitted BSSID
so we can parse it correctly.

Unfortunately, in quite a number of cases, we got this wrong
and were passing the wrong BSSID or useless information:
 * the mgmt->bssid from a frame is only the transmitted
   BSSID if the frame is a beacon
 * passing just one of the parameters as non-NULL isn't
   useful and ignored

In those case where we need to parse for a specific BSS we
always have a BSS structure pointer, representing the BSS
we need, whether transmitted or not. Thus, pass that pointer
to the parsing function instead of the two BSSIDs.

Also fix two bugs:
 * we need to re-parse all the elements for the other BSS
   when iterating the non-transmitted BSSes in scan
 * we need to parse for the correct BSS when setting up
   the channel data in client code

Fixes: 78ac51f81532 ("mac80211: support multi-bssid")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index b656cb647763..6991c4c479da 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -1256,8 +1256,7 @@ ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
 	if (baselen > len)
 		return;
 
-	elems = ieee802_11_parse_elems(pos, len - baselen, false, mgmt->bssid,
-				       NULL);
+	elems = ieee802_11_parse_elems(pos, len - baselen, false, NULL);
 	if (!elems)
 		return;
 
@@ -1326,7 +1325,7 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 
 	elems = ieee802_11_parse_elems(mgmt->u.probe_resp.variable,
 				       len - baselen,
-				       false, mgmt->bssid, NULL);
+				       false, NULL);
 	if (!elems)
 		return;
 
@@ -1468,8 +1467,7 @@ static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
 	pos = mgmt->u.action.u.chan_switch.variable;
 	baselen = offsetof(struct ieee80211_mgmt,
 			   u.action.u.chan_switch.variable);
-	elems = ieee802_11_parse_elems(pos, len - baselen, true,
-				       mgmt->bssid, NULL);
+	elems = ieee802_11_parse_elems(pos, len - baselen, true, NULL);
 	if (!elems)
 		return;