下面是option字段值的列表
Kind Meaning Reference
---- ------------------------------- ---------
0 End of Option List [RFC793]
1 No-Operation [RFC793]
2 Maximum Segment Size [RFC793]
3 WSOPT - Window Scale [RFC1323]
4 SACK Permitted [RFC2018]
5 SACK [RFC2018]
6 Echo (obsoleted by option 8) [RFC1072]
7 Echo Reply (obsoleted by option 8)[RFC1072]
8 TSOPT - Time Stamp Option [RFC1323]
9 Partial Order Connection Permitted[RFC1693]
10 Partial Order Service Profile [RFC1693]
11 CC &nbs