传输层 UDP/TCP

最后更新于:2022-04-02 04:06:51

[TOC] ## IP UDP TCP 关系 ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/fa/7f/fa7febcdc66b95b3ecc8f71e45da1f02_960x464.png) ## IP报文 ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/5b/95/5b958ee72a185f03135afce19906b174_1978x1164.png) ## UDP 报文 ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/ee/31/ee3183f672d851f44aefdc6b53d1eb77_1132x452.png) ## TCP 的报文 ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/67/87/678786472d246a108b0f741bfc6109f9_1562x654.png) ## 总结 ip 报文长度为20 udp 报文长度为16 tcp 报文长度为20 ``` 假设报文为 pack ip+udp的报文: ip = pack[:20] udp = pack[20:20+8] ip+tcp的报文长度: ip = pack[:20] udp = pack[20:20+20] ``` 可以查看 python解析报文的示例 [python解析IP/TCP/UDP 报文](../../python/%E5%86%85%E7%BD%AE%E5%8C%85/struct%E5%A4%A7-%E5%B0%8F%E7%AB%AF%E5%BA%8F.md)
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