Simplify HT Capabilities element parsing

Check the element length in the parser and remove the length field from
struct ieee802_11_elems since the element is of fixed length.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/ap/drv_callbacks.c

@@ -126,8 +126,6 @@ int hostapd_notif_assoc(struct hostapd_data *hapd, const u8 *addr,
 #ifdef CONFIG_IEEE80211N
 #ifdef NEED_AP_MLME
 	if (elems.ht_capabilities &&
-	    elems.ht_capabilities_len >=
-	    sizeof(struct ieee80211_ht_capabilities) &&
 	    (hapd->iface->conf->ht_capab &
 	     HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET)) {
 		struct ieee80211_ht_capabilities *ht_cap =

src/ap/ieee802_11.c

@@ -1282,8 +1282,7 @@ static u16 check_assoc_ies(struct hostapd_data *hapd, struct sta_info *sta,
 	if (resp != WLAN_STATUS_SUCCESS)
 		return resp;
 #ifdef CONFIG_IEEE80211N
-	resp = copy_sta_ht_capab(hapd, sta, elems.ht_capabilities,
-				 elems.ht_capabilities_len);
+	resp = copy_sta_ht_capab(hapd, sta, elems.ht_capabilities);
 	if (resp != WLAN_STATUS_SUCCESS)
 		return resp;
 	if (hapd->iconf->ieee80211n && hapd->iconf->require_ht &&

src/ap/ieee802_11.h

@@ -62,7 +62,7 @@ void hostapd_get_vht_capab(struct hostapd_data *hapd,
 			   struct ieee80211_vht_capabilities *vht_cap,
 			   struct ieee80211_vht_capabilities *neg_vht_cap);
 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
-		      const u8 *ht_capab, size_t ht_capab_len);
+		      const u8 *ht_capab);
 u16 copy_sta_vendor_vht(struct hostapd_data *hapd, struct sta_info *sta,
 			const u8 *ie, size_t len);
 

src/ap/ieee802_11_ht.c

@@ -310,7 +310,7 @@ void hostapd_2040_coex_action(struct hostapd_data *hapd,
 
 
 u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
-		      const u8 *ht_capab, size_t ht_capab_len)
+		      const u8 *ht_capab)
 {
 	/*
 	 * Disable HT caps for STAs associated to no-HT BSSes, or for stations
@@ -318,7 +318,6 @@ u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
 	 * frame.
 	 */
 	if (!ht_capab ||
-	    ht_capab_len < sizeof(struct ieee80211_ht_capabilities) ||
 	    !(sta->flags & WLAN_STA_WMM) || hapd->conf->disable_11n) {
 		sta->flags &= ~WLAN_STA_HT;
 		os_free(sta->ht_capabilities);

src/common/hw_features_common.c

@@ -335,9 +335,7 @@ int check_40mhz_2g4(struct hostapd_hw_modes *mode,
 
 		ieee802_11_parse_elems((u8 *) (bss + 1), bss->ie_len, &elems,
 				       0);
-		if (elems.ht_capabilities &&
-		    elems.ht_capabilities_len >=
-		    sizeof(struct ieee80211_ht_capabilities)) {
+		if (elems.ht_capabilities) {
 			struct ieee80211_ht_capabilities *ht_cap =
 				(struct ieee80211_ht_capabilities *)
 				elems.ht_capabilities;

src/common/ieee802_11_common.c

@@ -265,8 +265,9 @@ ParseRes ieee802_11_parse_elems(const u8 *start, size_t len,
 			elems->timeout_int = pos;
 			break;
 		case WLAN_EID_HT_CAP:
+			if (elen < sizeof(struct ieee80211_ht_capabilities))
+				break;
 			elems->ht_capabilities = pos;
-			elems->ht_capabilities_len = elen;
 			break;
 		case WLAN_EID_HT_OPERATION:
 			elems->ht_operation = pos;

src/common/ieee802_11_common.h

@@ -61,7 +61,6 @@ struct ieee802_11_elems {
 	u8 supp_channels_len;
 	u8 mdie_len;
 	u8 ftie_len;
-	u8 ht_capabilities_len;
 	u8 ht_operation_len;
 	u8 mesh_config_len;
 	u8 mesh_id_len;

src/rsn_supp/tdls.c

@@ -1577,9 +1577,7 @@ static int copy_supp_rates(const struct wpa_eapol_ie_parse *kde,
 static int copy_peer_ht_capab(const struct wpa_eapol_ie_parse *kde,
 			      struct wpa_tdls_peer *peer)
 {
-	if (!kde->ht_capabilities ||
-	    kde->ht_capabilities_len <
-	    sizeof(struct ieee80211_ht_capabilities) ) {
+	if (!kde->ht_capabilities) {
 		wpa_printf(MSG_DEBUG, "TDLS: No supported ht capabilities "
 			   "received");
 		return 0;

src/rsn_supp/wpa_ie.c

@@ -553,9 +553,9 @@ int wpa_supplicant_parse_ies(const u8 *buf, size_t len,
 		} else if (*pos == WLAN_EID_EXT_SUPP_RATES) {
 			ie->ext_supp_rates = pos;
 			ie->ext_supp_rates_len = pos[1] + 2;
-		} else if (*pos == WLAN_EID_HT_CAP) {
+		} else if (*pos == WLAN_EID_HT_CAP &&
+			   pos[1] >= sizeof(struct ieee80211_ht_capabilities)) {
 			ie->ht_capabilities = pos + 2;
-			ie->ht_capabilities_len = pos[1];
 		} else if (*pos == WLAN_EID_VHT_AID) {
 			if (pos[1] >= 2)
 				ie->aid = WPA_GET_LE16(pos + 2) & 0x3fff;

src/rsn_supp/wpa_ie.h

@@ -50,7 +50,6 @@ struct wpa_eapol_ie_parse {
 	const u8 *ext_supp_rates;
 	size_t ext_supp_rates_len;
 	const u8 *ht_capabilities;
-	size_t ht_capabilities_len;
 	const u8 *vht_capabilities;
 	size_t vht_capabilities_len;
 	const u8 *supp_channels;

wpa_supplicant/mesh_mpm.c

@@ -551,8 +551,7 @@ static struct sta_info * mesh_mpm_add_peer(struct wpa_supplicant *wpa_s,
 	mesh_mpm_init_link(wpa_s, sta);
 
 #ifdef CONFIG_IEEE80211N
-	copy_sta_ht_capab(data, sta, elems->ht_capabilities,
-			elems->ht_capabilities_len);
+	copy_sta_ht_capab(data, sta, elems->ht_capabilities);
 	update_ht_state(data, sta);
 #endif /* CONFIG_IEEE80211N */