\n\ttypedef struct DLC_Header
\n{
\n unsigned char DesMAC[6]; \/\/\u4ee5\u592a\u7f51\u76ee\u7684\u5730\u5740
\n unsigned char SrcMAC[6]; \/\/\u4ee5\u592a\u7f51\u6e90\u5730\u5740
\n unsigned short EtherType; \/\/\u4e0a\u5c42\u534f\u8bae\u7c7b\u578b
\n} DLCHEADER;<\/p>\n
typedef struct ipheader
\n{
\n unsigned char ip_hl:4; \/*header length(\u62a5\u5934\u957f\u5ea6\uff09*\/
\n unsigned char ip_v:4; \/*version(\u7248\u672c)*\/
\n unsigned char ip_tos; \/*type os service\u670d\u52a1\u7c7b\u578b*\/
\n unsigned short int ip_len; \/*total length (\u603b\u957f\u5ea6)*\/
\n unsigned short int ip_id; \/*identification (\u6807\u8bc6\u7b26)*\/
\n unsigned short int ip_off; \/*fragment offset field(\u6bb5\u79fb\u4f4d\u57df)*\/
\n unsigned char ip_ttl; \/*time to live (\u751f\u5b58\u65f6\u95f4)*\/
\n unsigned char ip_p; \/*protocol(\u4e0a\u5c42\u534f\u8bae\u7c7b\u578b)*\/
\n unsigned short int ip_sum; \/*checksum(\u6821\u9a8c\u548c)*\/
\n unsigned char ip_src[4]; \/*source address(\u6e90\u5730\u5740)*\/
\n unsigned char ip_dst[4]; \/*destination address(\u76ee\u7684\u5730\u5740)*\/
\n} IP;<\/p>\n
typedef struct tcpheader
\n{
\n unsigned short int sport; \/*source port (\u6e90\u7aef\u53e3\u53f7)*\/
\n unsigned short int dport; \/*destination port(\u76ee\u7684\u7aef\u53e3\u53f7)*\/
\n unsigned int th_seq; \/*sequence number(\u5305\u7684\u5e8f\u5217\u53f7)*\/
\n unsigned int th_ack; \/*acknowledgement number(\u786e\u8ba4\u5e94\u7b54\u53f7)*\/
\n unsigned char th_x:4; \/*unused(\u672a\u4f7f\u7528)*\/
\n unsigned char th_off:4; \/*data offset(\u6570\u636e\u504f\u79fb\u91cf)*\/
\n unsigned char Flags; \/*\u6807\u5fd7\u5168*\/
\n unsigned short int th_win; \/*windows(\u7a97\u53e3)*\/
\n unsigned short int th_sum; \/*checksum(\u6821\u9a8c\u548c)*\/
\n unsigned short int th_urp; \/*urgent pointer(\u7d27\u6025\u6307\u9488)*\/
\n} TCP;\n<\/p>\n
\n\t\n<\/p>\n
\n\ttypedef struct pseudoTcpHeader\n<\/p>\n
{
\n unsigned long int ip_src;
\n unsigned long int ip_dst;
\n unsigned char zero; \/\/always zero
\n unsigned char protocol; \/\/ = 0x06
\n unsigned short tcp_len; \/\/TCP\u5934+\u6570\u636e \uff08\u4e0d\u52a0\u4f2a\u5934\u957f\u5ea6\uff09<\/p>\n
\n\t} TCP_Psd_Header;\n<\/p>\n
\n\t\n<\/p>\n
\n\tunsigned short int checksum(unsigned short int *buffer,int size)
\n{
\n unsigned long cksum=0;
\n while(size>1)
\n {
\n cksum+=*buffer++;
\n size-=sizeof(unsigned short int);
\n }
\n if(size)
\n {
\n cksum+=*(UCHAR *)buffer;
\n }
\n \/\/\u5c0632\u4f4d\u6570\u8f6c\u6362\u621016
\n while (cksum>>16)
\n cksum=(cksum>>16)+(cksum & 0xffff);
\n return (unsigned short int)(~cksum);
\n}\n<\/p>\n
\n\t\n<\/p>\n
void PacketCheckSum(unsigned char Packet[])
\n{
\n TCP_Psd_Header *TPH=NULL;
\n char *buffer=NULL;
\n unsigned int size=0;<\/p>\n
DLCHEADER *DLCHeader=NULL;
\n IP *IPHeader=NULL;
\n TCP *TCPHeader=NULL;<\/p>\n
DLCHeader=(DLCHEADER *)Packet;
\n IPHeader=(IP *)(Packet+sizeof(DLCHEADER));
\n TCPHeader=(TCP *)(Packet+sizeof(DLCHEADER)+sizeof(IP));<\/p>\n
TCPHeader->th_sum=0;
\n size=ntohs(IPHeader->ip_len);
\n buffer=(char *)malloc(size+sizeof(TCP_Psd_Header));
\n if(buffer==NULL) return;
\n memset(buffer,NULL,size+sizeof(TCP_Psd_Header));
\n TPH=(TCP_Psd_Header *)buffer;
\n TPH->ip_dst=*(unsigned long int *)IPHeader->ip_dst;
\n TPH->ip_src=*(unsigned long int *)IPHeader->ip_src;
\n TPH->protocol=0x06;
\n TPH->tcp_len=htons(size-sizeof(IP));<\/p>\n
memcpy(buffer+sizeof(TCP_Psd_Header),TCPHeader,size-sizeof(IP));<\/p>\n
TCPHeader->th_sum=checksum(buffer,size-sizeof(IP)+sizeof(TCP_Psd_Header));<\/p>\n
free(buffer);<\/p>\n
return;
\n}<\/p>\n","protected":false},"excerpt":{"rendered":"
typedef struct pseudoTcpHeader
\n{
\n unsigned long int ip_src;
\n unsigned long int ip_dst;
\n unsigned char zero; …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[324],"tags":[],"class_list":["post-99","post","type-post","status-publish","format-standard","hentry"],"yoast_head":"\n