WFD: Add preliminary WSD request processing and response

This commit does not yet address support for different device roles,
i.e., the same set of subelements are returned regardless of which
role was indicated in the request.

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

wpa_supplicant/p2p_supplicant.c

@@ -1479,6 +1479,62 @@ static void wpas_sd_req_upnp(struct wpa_supplicant *wpa_s,
 }
 
 
+#ifdef CONFIG_WIFI_DISPLAY
+static void wpas_sd_req_wfd(struct wpa_supplicant *wpa_s,
+			    struct wpabuf *resp, u8 srv_trans_id,
+			    const u8 *query, size_t query_len)
+{
+	const u8 *pos;
+	u8 role;
+	u8 *len_pos;
+
+	wpa_hexdump(MSG_DEBUG, "P2P: SD Request for WFD", query, query_len);
+
+	if (!wpa_s->global->wifi_display) {
+		wpa_printf(MSG_DEBUG, "P2P: WFD protocol not available");
+		wpas_sd_add_proto_not_avail(resp, P2P_SERV_WIFI_DISPLAY,
+					    srv_trans_id);
+		return;
+	}
+
+	if (query_len < 1) {
+		wpa_printf(MSG_DEBUG, "P2P: Missing WFD Requested Device "
+			   "Role");
+		return;
+	}
+
+	if (wpabuf_tailroom(resp) < 5)
+		return;
+
+	pos = query;
+	role = *pos++;
+	wpa_printf(MSG_DEBUG, "P2P: WSD for device role 0x%x", role);
+
+	/* TODO: role specific handling */
+
+	/* Length (to be filled) */
+	len_pos = wpabuf_put(resp, 2);
+	wpabuf_put_u8(resp, P2P_SERV_WIFI_DISPLAY);
+	wpabuf_put_u8(resp, srv_trans_id);
+	wpabuf_put_u8(resp, P2P_SD_SUCCESS); /* Status Code */
+
+	while (pos < query + query_len) {
+		if (*pos < MAX_WFD_SUBELEMS &&
+		    wpa_s->global->wfd_subelem[*pos] &&
+		    wpabuf_tailroom(resp) >=
+		    wpabuf_len(wpa_s->global->wfd_subelem[*pos])) {
+			wpa_printf(MSG_DEBUG, "P2P: Add WSD response "
+				   "subelement %u", *pos);
+			wpabuf_put_buf(resp, wpa_s->global->wfd_subelem[*pos]);
+		}
+		pos++;
+	}
+
+	WPA_PUT_LE16(len_pos, (u8 *) wpabuf_put(resp, 0) - len_pos - 2);
+}
+#endif /* CONFIG_WIFI_DISPLAY */
+
+
 void wpas_sd_request(void *ctx, int freq, const u8 *sa, u8 dialog_token,
 		     u16 update_indic, const u8 *tlvs, size_t tlvs_len)
 {
@@ -1570,6 +1626,12 @@ void wpas_sd_request(void *ctx, int freq, const u8 *sa, u8 dialog_token,
 			wpas_sd_req_upnp(wpa_s, resp, srv_trans_id,
 					 pos, tlv_end - pos);
 			break;
+#ifdef CONFIG_WIFI_DISPLAY
+		case P2P_SERV_WIFI_DISPLAY:
+			wpas_sd_req_wfd(wpa_s, resp, srv_trans_id,
+					pos, tlv_end - pos);
+			break;
+#endif /* CONFIG_WIFI_DISPLAY */
 		default:
 			wpa_printf(MSG_DEBUG, "P2P: Unavailable service "
 				   "protocol %u", srv_proto);