recvframe_pull
recvframe_pull(pnextrframe, wlanhdr_offset);
ptr = recvframe_pull(precvframe, (rmv_len-sizeof(struct ethhdr)+2)-24);
ptr = recvframe_pull(precvframe, (rmv_len-sizeof(struct ethhdr) + (bsnaphdr?2:0)));
recvframe_pull(prframe, prframe->u.hdr.attrib.hdrlen);
recvframe_pull(prframe, prframe->u.hdr.attrib.iv_len);