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计算校验和
校验和算法描述:为保证网络上传输的数据的可靠性,在许多协议中都设置了校验和项,例如:IPv4、ICMPv4、IGMPV4、ICMPv6、UDP...
计算校验和
校验和算法描述:为保证网络上传输的数据的可靠性,在许多协议中都设置了校验和项,例如:IPv4、ICMPv4、IGMPV4、ICMPv6、UDP和TCP 等等。计算这些校验和的算法称为网际校验和算法,简单来说就是:把被校验的数据16位进行累加,然后取反码,若数据字节长度为奇数,则数据尾部补一个字节的0以凑成偶数。
由于从输入文件读入的数据不能直接满足计算校验和的条件,所以首先对从文件读入缓冲区的数据进行预处理,即读入缓冲区时忽略空格。由于累加是按16位进行的,所以每次从缓冲区中读出4个字符,并将字符转换成对应的16进制数字,如此依次累加,直至数据全部读完。
还有一种情况,即如果数据长度为奇数个字节,则需要判断,并补0累加。程序中利用的是缓冲区长度计数器i和当前读取到计数器j判断数据长度是否为奇数。即如果数据长度为偶数,则读完数据时当前读取到计数器j的值应与缓冲区长度i相等,而如果数据长度为奇数,则读完数据时,当前读取到计数器j>缓冲区长度i,此时需将缓冲区中剩余的两个字符读出,并补0,转换成相应16进制数以后参与累加。
当累加结束后,将累加和的16位以上数据位移下再进行一次累加,并对最后累加和取反即得所求校验和。
-calculated checksum checksum algorithm Description : To ensure the network transmission of data reliability, in many of the agreements are set up and calibration, for example : IPv4, ICMPv4, IGMPV4, ICMPv6. UDP and TCP so on. Calculating checksum algorithm called the Internet checksum algorithm, the simple answer is : as has been the calibration data for 16 cumulative, and then take the anti-code, if the data byte length of the odd, data will make up the tai
- 2022-01-26 06:39:03下载
- 积分:1
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硬盘读取你可以自动读取服务器的信息,对服务器内容进行操作...
硬盘读取你可以自动读取服务器的信息,对服务器内容进行操作-Hard to read the server you can automatically read the information on the content server to operate
- 2022-03-24 22:28:18下载
- 积分:1
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achieving TCP and udp simultaneously network communications, including chat and...
实现TCP和udp
同时进行网络通信
包括聊天和传送文件
具有很高的学习价值
-achieving TCP and udp simultaneously network communications, including chat and transmission of documents with very high values of learning
- 2023-04-21 07:30:03下载
- 积分:1
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网络端口进程监视器,作者为www.6663.net论坛坛主
网络端口进程监视器,作者为www.6663.net论坛坛主-Network port process monitors, author www.6663.net Forum Administrator
- 2022-05-16 12:28:51下载
- 积分:1
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网络ping编程
网络ping编程-Ping network programming
- 2022-07-21 09:58:19下载
- 积分:1
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C#高并发SOCKET源码,
SOCKET,带测试程序,客户端和服务端,支持文件传输
- 2022-02-28 20:39:59下载
- 积分:1
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这是一个语音聊天的源代码,完成的主要功能,但收购…
这是一个语音聊天的源代码,完成了主要的功能,只是采集的语音信号没有编码就直接发送出去了,有兴趣的朋友可以-This a voice chat source code, to complete the main function, but the acquisition of the voice signal coding not directly sent away, interested friends can s
- 2022-06-27 14:25:26下载
- 积分:1
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无限制的单工协议发送端和接收端程序,网络通信协议实例编程的基础...
无限制的单工协议发送端和接收端程序,网络通信协议实例编程的基础-unrestricted simplex agreement to send and receive software, network communication protocol based programming examples
- 2023-06-07 21:10:03下载
- 积分:1
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Very good solution to large file transfers, as well as send video data can also...
很好的解决大文件传输,以及视频数据的发送也可以借鉴.-Very good solution to large file transfers, as well as send video data can also learn from.
- 2023-05-16 04:15:02下载
- 积分:1
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Socket API procedures
SocketAPI的程序-Socket API procedures
- 2022-02-20 05:19:27下载
- 积分:1