Include Extended Capabilities element based on scan results

Add Extended Capabilities element to association request only if the AP
included this element in Beacon/Probe Response frames. This is a
workaround to address interoperability issues with some older APs that
do not seem to be able to handle Extended Capabilities element in
(Re)Association Request frames.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index eab1c39a41d8d51844959168e9fa542056251c67..99e48eb6b1df66c6dbb09a9f6bb957eae9138003 100644 (file)
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -1278,8 +1278,6 @@ void wpa_supplicant_associate(struct wpa_supplicant *wpa_s,
        int wep_keys_set = 0;
        int assoc_failed = 0;
        struct wpa_ssid *old_ssid;
-       u8 ext_capab[10];
-       int ext_capab_len;
 #ifdef CONFIG_HT_OVERRIDES
        struct ieee80211_ht_capabilities htcaps;
        struct ieee80211_ht_capabilities htcaps_mask;
@@ -1491,15 +1489,27 @@ void wpa_supplicant_associate(struct wpa_supplicant *wpa_s,
        }
 #endif /* CONFIG_HS20 */
 
-       ext_capab_len = wpas_build_ext_capab(wpa_s, ext_capab);
-       if (ext_capab_len > 0) {
-               u8 *pos = wpa_ie;
-               if (wpa_ie_len > 0 && pos[0] == WLAN_EID_RSN)
-                       pos += 2 + pos[1];
-               os_memmove(pos + ext_capab_len, pos,
-                          wpa_ie_len - (pos - wpa_ie));
-               wpa_ie_len += ext_capab_len;
-               os_memcpy(pos, ext_capab, ext_capab_len);
+       /*
+        * Workaround: Add Extended Capabilities element only if the AP
+        * included this element in Beacon/Probe Response frames. Some older
+        * APs seem to have interoperability issues if this element is
+        * included, so while the standard may require us to include the
+        * element in all cases, it is justifiable to skip it to avoid
+        * interoperability issues.
+        */
+       if (!bss || wpa_bss_get_ie(bss, WLAN_EID_EXT_CAPAB)) {
+               u8 ext_capab[10];
+               int ext_capab_len;
+               ext_capab_len = wpas_build_ext_capab(wpa_s, ext_capab);
+               if (ext_capab_len > 0) {
+                       u8 *pos = wpa_ie;
+                       if (wpa_ie_len > 0 && pos[0] == WLAN_EID_RSN)
+                               pos += 2 + pos[1];
+                       os_memmove(pos + ext_capab_len, pos,
+                                  wpa_ie_len - (pos - wpa_ie));
+                       wpa_ie_len += ext_capab_len;
+                       os_memcpy(pos, ext_capab, ext_capab_len);
+               }
        }
 
        wpa_clear_keys(wpa_s, bss ? bss->bssid : NULL);