AL_IP_ALIGNMENT_OFFSET
al_buf->addr = segs[0].ds_addr + AL_IP_ALIGNMENT_OFFSET;
al_buf->len = rx_info->data_size - AL_IP_ALIGNMENT_OFFSET;
smbuf->m_data = smbuf->m_data + AL_IP_ALIGNMENT_OFFSET;
memcpy(smbuf->m_data, mbuf->m_data + AL_IP_ALIGNMENT_OFFSET, len);
mbuf->m_data = mbuf->m_data + AL_IP_ALIGNMENT_OFFSET;