MAX_TCPOPTLEN
u_int8_t opts[MAX_TCPOPTLEN], *opt = opts;
KASSERT(cnt <= MAX_TCPOPTLEN);
KASSERT(cnt <= MAX_TCPOPTLEN);
u_char opt[MAX_TCPOPTLEN], *optp;
t_sack_block[(MAX_TCPOPTLEN - 2) / (sizeof(u_int32_t) * 2)];
tlen = hlen + sizeof(struct tcphdr) + MAX_TCPOPTLEN;