UDP校验和

Question

谁有计算UDP校验和的代码发出来参考下 谢谢了

Answer 1

http://topic.csdn.net/t/20050301/21/3816586.html

Answer 2

以下是我的源代码，   
    
  ////////////////////////////////////////////////////////////////////   
        char*   szSendBuf=Buffer;   
      
  //填充IP首部   
        ipHeader.h_lenver=iphdr->h_lenver;   
        ipHeader.tos=iphdr->tos;   
        ipHeader.total_len=iphdr->total_len;   
        ipHeader.ident=iphdr->ident;   
        ipHeader.frag_and_flags=iphdr->frag_and_flags;   
        ipHeader.ttl=iphdr->ttl;   
        ipHeader.proto=iphdr->proto;   
        ipHeader.checksum=iphdr->checksum;                                         //注意添校验和   
        ipHeader.sourceIP=inet_addr(FilSou);   
        ipHeader.destIP=inet_addr(FilDes);   
    
        //填充UDP首部   
        udpHeader.uh_sport=pUdpHeader->uh_sport;   
        udpHeader.uh_dport=pUdpHeader->uh_sport;   
        udpHeader.uh_len=pUdpHeader->uh_len;   
        udpHeader.uh_sum=/*pUdpHeader->uh_sum*/0;   
    
    
        int     iUdpChecksumSize   =   0;   
        ZeroMemory(Buffer,MAX_PACKET_SIZE);         //初始化发送缓冲区   
    
        memcpy(szSendBuf,   &ipHeader.sourceIP,   sizeof(ipHeader.sourceIP));     
        szSendBuf   +=   sizeof(ipHeader.sourceIP);   
        iUdpChecksumSize   +=   sizeof(ipHeader.sourceIP);   
    
        memcpy(szSendBuf,   &ipHeader.destIP,   sizeof(ipHeader.destIP));       
          
        szSendBuf   +=   sizeof(ipHeader.destIP);   
        iUdpChecksumSize   +=   sizeof(ipHeader.destIP);   
    
        szSendBuf++;   
        iUdpChecksumSize   +=   1;   
    
        memcpy(szSendBuf,   &ipHeader.proto,   sizeof(ipHeader.proto));     
        szSendBuf   +=   sizeof(ipHeader.proto);     
        iUdpChecksumSize   +=   sizeof(ipHeader.proto);   
    
        memcpy(szSendBuf,   &udpHeader.uh_len,   sizeof(udpHeader.uh_len));     
        szSendBuf   +=   sizeof(udpHeader.uh_len);   
        iUdpChecksumSize   +=   sizeof(udpHeader.uh_len);   
    
        memcpy(szSendBuf,   &udpHeader,   sizeof(udpHeader));     
        szSendBuf   +=   sizeof(udpHeader);   
        iUdpChecksumSize   +=   sizeof(udpHeader);   
    
        int   UdpLenth   =   udpHeader.uh_len;   
          
        
        char   temp[2000];   
    
        for   (int   m=0;   m<UdpLenth;m++,szSendBuf++)   
        temp[m]=*szSendBuf;   
    
    //       *szSendBuf   ^=1;   
    
        iUdpChecksumSize   +=UdpLenth;   
    
        unsigned   cksum   =   checksum((USHORT   *)Buffer,   iUdpChecksumSize);   
        udpHeader.uh_sum   =   cksum;   
    
        ZeroMemory(Buffer,   MAX_PACKET_SIZE);   
        szSendBuf   =   Buffer;   
    
        memcpy(szSendBuf,   &ipHeader,   sizeof(ipHeader));   
        szSendBuf   +=   sizeof(ipHeader);   
        memcpy(szSendBuf,   &udpHeader,   sizeof(udpHeader));   
        szSendBuf   +=   sizeof(udpHeader);   
        memcpy(szSendBuf,temp,   UdpLenth);   
    
        if(bind(sock,   (SOCKADDR     FAR     *)&Sender,     sizeof(Sender))!=0)       
                {       
                                printf(     "Can't     bind     sender     socket     to     local     port!Program     stop.\n     ");//初始化失败返回-1       
                                return     -1;       
                }     
    
    
        int   rect=sendto(sock,   Buffer,   RecvSize,     
                                0,   (struct   sockaddr*)&addr_in,   sizeof(addr_in));     
    
        if   (rect==SOCKET_ERROR)     
        {     
                printf("UDP   send   error!:%d\\                 n",WSAGetLastError());     
                return   false;     
        }     
        else     
                printf("UDP   send   ok!\n");     
    
  ////////////////////////////////////////////////////////////////   
    
    
    
    
    
  //CheckSum:计算校验和的子函数     
  USHORT   checksum(USHORT   *buffer,   int   size)     
  {     
  unsigned   long   cksum=0;     
  while(size   >1)     
  {     
  cksum+=*buffer++;     
  size   -=sizeof(USHORT);     
  }     
  if(size   )         
  {     
  cksum   +=   *(UCHAR*)buffer;     
  }     
    
  cksum   =   (cksum   >>   16)   +   (cksum   &   0xffff);     
  cksum   +=   (cksum   >>16);     
  return   (USHORT)(~cksum);     
  }