m_copyup
m = m_copyup(m, hlen, (max_linkhdr + 3) & ~3);
m = m_copyup(m, off + sizeof(struct tcphdr), 0);
m = m_copyup(m, iphlen + sizeof(struct udphdr), 0);
m = m_copyup(m, off + sizeof(struct icmp6_hdr), 0);
if ((m = m_copyup(m, sizeof(struct ip6_hdr),
m = m_copyup(m, off + sizeof(struct udphdr), 0);
struct mbuf *m_copyup(struct mbuf *, int, int);
*m = m_copyup(*m, hlen,