MBO: Add support to send ANQP request to get cellular preference

This extends ANQP_GET command to support querying MBO cellular
preference also. The cellular preference can be requested along with
neigbor report by appending mbo:1 to the command arguments.

For example:
ANQP_GET <bssid> 272,mbo:1

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

src/common/ieee802_11_defs.h

@@ -1180,6 +1180,10 @@ enum wfa_wnm_notif_subelem_id {
 	WFA_WNM_NOTIF_SUBELEM_CELL_DATA_CAPA = 3,
 };
 
+/* MBO v0.0_r25, 4.3: MBO ANQP-elements */
+#define MBO_ANQP_OUI_TYPE 0x12
+#define MBO_ANQP_SUBTYPE_CELL_CONN_PREF 1
+
 /* Wi-Fi Direct (P2P) */
 
 #define P2P_OUI_TYPE 9

wpa_supplicant/ctrl_iface.c

@@ -6383,6 +6383,7 @@ static int get_anqp(struct wpa_supplicant *wpa_s, char *dst)
 	u16 id[MAX_ANQP_INFO_ID];
 	size_t num_id = 0;
 	u32 subtypes = 0;
+	int get_cell_pref = 0;
 
 	used = hwaddr_aton2(dst, dst_addr);
 	if (used < 0)
@@ -6400,6 +6401,15 @@ static int get_anqp(struct wpa_supplicant *wpa_s, char *dst)
 #else /* CONFIG_HS20 */
 			return -1;
 #endif /* CONFIG_HS20 */
+		} else if (os_strncmp(pos, "mbo:", 4) == 0) {
+#ifdef CONFIG_MBO
+			int num = atoi(pos + 4);
+			if (num != MBO_ANQP_SUBTYPE_CELL_CONN_PREF)
+				return -1;
+			get_cell_pref = 1;
+#else /* CONFIG_MBO */
+			return -1;
+#endif /* CONFIG_MBO */
 		} else {
 			id[num_id] = atoi(pos);
 			if (id[num_id])
@@ -6414,7 +6424,8 @@ static int get_anqp(struct wpa_supplicant *wpa_s, char *dst)
 	if (num_id == 0)
 		return -1;
 
-	return anqp_send_req(wpa_s, dst_addr, id, num_id, subtypes);
+	return anqp_send_req(wpa_s, dst_addr, id, num_id, subtypes,
+			     get_cell_pref);
 }
 
 

wpa_supplicant/interworking.c

@@ -2692,10 +2692,11 @@ void interworking_stop_fetch_anqp(struct wpa_supplicant *wpa_s)
 
 
 int anqp_send_req(struct wpa_supplicant *wpa_s, const u8 *dst,
-		  u16 info_ids[], size_t num_ids, u32 subtypes)
+		  u16 info_ids[], size_t num_ids, u32 subtypes,
+		  int get_cell_pref)
 {
 	struct wpabuf *buf;
-	struct wpabuf *hs20_buf = NULL;
+	struct wpabuf *extra_buf = NULL;
 	int ret = 0;
 	int freq;
 	struct wpa_bss *bss;
@@ -2718,15 +2719,31 @@ int anqp_send_req(struct wpa_supplicant *wpa_s, const u8 *dst,
 
 #ifdef CONFIG_HS20
 	if (subtypes != 0) {
-		hs20_buf = wpabuf_alloc(100);
-		if (hs20_buf == NULL)
+		extra_buf = wpabuf_alloc(100);
+		if (extra_buf == NULL)
 			return -1;
-		hs20_put_anqp_req(subtypes, NULL, 0, hs20_buf);
+		hs20_put_anqp_req(subtypes, NULL, 0, extra_buf);
 	}
 #endif /* CONFIG_HS20 */
 
-	buf = anqp_build_req(info_ids, num_ids, hs20_buf);
-	wpabuf_free(hs20_buf);
+#ifdef CONFIG_MBO
+	if (get_cell_pref) {
+		struct wpabuf *mbo;
+
+		mbo = mbo_build_anqp_buf(wpa_s, bss);
+		if (mbo) {
+			if (wpabuf_resize(&extra_buf, wpabuf_len(mbo))) {
+				wpabuf_free(extra_buf);
+				return -1;
+			}
+			wpabuf_put_buf(extra_buf, mbo);
+			wpabuf_free(mbo);
+		}
+	}
+#endif /* CONFIG_MBO */
+
+	buf = anqp_build_req(info_ids, num_ids, extra_buf);
+	wpabuf_free(extra_buf);
 	if (buf == NULL)
 		return -1;
 

wpa_supplicant/interworking.h

@@ -12,7 +12,8 @@
 enum gas_query_result;
 
 int anqp_send_req(struct wpa_supplicant *wpa_s, const u8 *dst,
-		  u16 info_ids[], size_t num_ids, u32 subtypes);
+		  u16 info_ids[], size_t num_ids, u32 subtypes,
+		  int get_cell_pref);
 void anqp_resp_cb(void *ctx, const u8 *dst, u8 dialog_token,
 		  enum gas_query_result result,
 		  const struct wpabuf *adv_proto,

wpa_supplicant/mbo.c

@@ -14,6 +14,7 @@
 
 #include "utils/common.h"
 #include "common/ieee802_11_defs.h"
+#include "common/gas.h"
 #include "config.h"
 #include "wpa_supplicant_i.h"
 #include "driver_i.h"
@@ -805,3 +806,31 @@ void wpas_mbo_update_cell_capa(struct wpa_supplicant *wpa_s, u8 mbo_cell_capa)
 	wpas_mbo_send_wnm_notification(wpa_s, cell_capa, 7);
 	wpa_supplicant_set_default_scan_ies(wpa_s);
 }
+
+
+struct wpabuf * mbo_build_anqp_buf(struct wpa_supplicant *wpa_s,
+				   struct wpa_bss *bss)
+{
+	struct wpabuf *anqp_buf;
+	u8 *len_pos;
+
+	if (!wpa_bss_get_vendor_ie(bss, MBO_IE_VENDOR_TYPE)) {
+		wpa_printf(MSG_INFO, "MBO: " MACSTR
+			   " does not support MBO - cannot request MBO ANQP elements from it",
+			   MAC2STR(bss->bssid));
+		return NULL;
+	}
+
+	anqp_buf = wpabuf_alloc(10);
+	if (!anqp_buf)
+		return NULL;
+
+	len_pos = gas_anqp_add_element(anqp_buf, ANQP_VENDOR_SPECIFIC);
+	wpabuf_put_be24(anqp_buf, OUI_WFA);
+	wpabuf_put_u8(anqp_buf, MBO_ANQP_OUI_TYPE);
+
+	wpabuf_put_u8(anqp_buf, MBO_ANQP_SUBTYPE_CELL_CONN_PREF);
+	gas_anqp_set_element_len(anqp_buf, len_pos);
+
+	return anqp_buf;
+}

wpa_supplicant/wpa_supplicant_i.h

@@ -1204,6 +1204,8 @@ size_t wpas_mbo_ie_bss_trans_reject(struct wpa_supplicant *wpa_s, u8 *pos,
 				    size_t len,
 				    enum mbo_transition_reject_reason reason);
 void wpas_mbo_update_cell_capa(struct wpa_supplicant *wpa_s, u8 mbo_cell_capa);
+struct wpabuf * mbo_build_anqp_buf(struct wpa_supplicant *wpa_s,
+				   struct wpa_bss *bss);
 
 /**
  * wpa_supplicant_ctrl_iface_ctrl_rsp_handle - Handle a control response