VC++实现端口截听

long num;

DWORD val;

DWORD ret;

果是隐藏端口应用的话，可以在此处加一些判断

果是自己的包，就可以进行一些特殊处理，不是的话通过127.0.0.1进行转发

saddr.sin_family = AF_INET;

saddr.sin_addr.s_addr = inet_addr("127.0.0.1");

saddr.sin_port = htons(23);

if((sc=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==SOCKET_ERROR)

{

printf("error!socket failed!\n");

return -1;

}

val = 100;

if(setsockopt(sc,SOL_SOCKET,SO_RCVTIMEO,(char *)&val,sizeof(val))!=0)

{

ret = GetLastError();

return -1;

}

if(setsockopt(ss,SOL_SOCKET,SO_RCVTIMEO,(char *)&val,sizeof(val))!=0)

{

ret = GetLastError();

return -1;

}

if(connect(sc,(SOCKADDR *)&saddr,sizeof(saddr))!=0)

{

printf("error!socket connect failed!\n");

closesocket(sc);