txd_buf
m_copydata(m0, 0, len, txd->txd_buf + bufoff);
memset(txd->txd_buf + bufoff + len, 0,
m_copydata(m0, 0, len, txd->txd_buf + bufoff);
m_copydata(m0, 0, buflen, txd->txd_buf + bufoff);
m = txd->txd_buf;
txd->txd_buf = m;
hvn_bpf_mtap(txr, txd->txd_buf, BPF_D_OUT);
hvn_bpf_mtap(txr, tmp_txd->txd_buf, BPF_D_OUT);
struct mbuf *txd_buf;
txd->txd_buf = NULL;
if (txd->txd_buf == NULL)
m_freem(txd->txd_buf);
txd->txd_buf = NULL;