UPD.rar_UDP 协议_UDP 通信协议C_udp 广播_upd广播 代码_visual c

#include<stdlib.h> #include<iostream.h> #include<conio.h> #include<stdio.h> #include<winsock2.h> #include<windows.h> #pragma comment(lib,"ws2_32.lib") /* HANDLE hr,hl,hbusy; struct thrpar { SOCKET s; }; struct recpar { SOCKET srec; struct sockaddr_in addr; }; UINT recthread(LPVOID pp) { SOCKET srec,s2; struct recpar *prec=(struct recpar *)pp; sockaddr_in recaddr; srec=prec->srec; recaddr=prec->addr; char buf[256]; DWORD ret; printf("recv thread start!"); ret=recv(srec,buf,256,0); if(ret==0) { printf("connect close!"); closesocket(srec); return 0; } else if(ret==SOCKET_ERROR) { printf("connect error!"); closesocket(srec); return 0; } printf("recv data:%s",buf); return 0; } DWORD WINAPI listhread(LPVOID pp) { ::MessageBox(NULL,"enter the listhread","KK",MB_OK); struct thrpar *pthr=(struct thrpar*)pp; SOCKET sl,saccept; sockaddr_in here, there; char name[256]; struct hostent *phost; int ret; gethostname(name,256); phost=gethostbyname(name); here.sin_family=AF_INET; here.sin_port=htons(1024); here.sin_addr.S_un.S_un_b.s_b1=phost->h_addr_list[0][0]; here.sin_addr.S_un.S_un_b.s_b2=phost->h_addr_list[0][1]; here.sin_addr.S_un.S_un_b.s_b3=phost->h_addr_list[0][2]; here.sin_addr.S_un.S_un_b.s_b4=phost->h_addr_list[0][3]; sl=pthr->s; ret=bind(sl,(struct sockaddr *)&here,sizeof(here)); if(ret!=0) { printf("bind error"); return 0; } ret=listen(sl,5); if(ret!=0) { printf("listen error"); return 0; } while(true) { int nlen=sizeof(there); saccept=accept(sl,(struct sockaddr *)&there,&nlen); if(saccept==INVALID_SOCKET) { printf("accept socket invalid"); } DWORD wret=WaitForSingleObject(hbusy,500); if(wret==WAIT_TIMEOUT) { send(saccept,"\0",1,0); closesocket(saccept); continue ; } DWORD recid; struct recpar *prec; prec->addr=there; prec->srec=saccept; hr=CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)&listhread,prec,0,&recid); return 1; } return 1; } void main(void) { SOCKET s; sockaddr_in addrin; WSADATA wsdata; BOOL bsocket; char *smsg="this is a test"; WSAStartup(0x0202,&wsdata); s=WSASocket(AF_INET,SOCK_STREAM,0,NULL,0,WSA_FLAG_OVERLAPPED); hbusy=CreateSemaphore(NULL,0,2,NULL); struct thrpar *psc; psc=new struct thrpar; DWORD lisid; psc->s=s; hr=CreateThread(NULL,0,listhread,psc,0,&lisid); DWORD ret=WaitForSingleObject(hr,10000); if(ret==WAIT_OBJECT_0)printf("thread time out%d\r\n",lisid); }*/ void main(void) { SOCKET s; sockaddr_in from,a; WSADATA wsdata; BOOL optval; //启动SOCKET库，版本为2.0 WSAStartup(0x0202,&wsdata); optval=TRUE; //然后赋值给两个地址，一个用来绑定套接字，一个用来从网络上的广播地址接收消息； a.sin_family=AF_INET; a.sin_addr.s_addr=0; a.sin_port=htons(5050); from.sin_family=AF_INET; from.sin_addr.s_addr=INADDR_BROADCAST; from.sin_port=htons(5050); int fromlength=sizeof(SOCKADDR); //用UDP初始化套接字 s=socket(AF_INET,SOCK_DGRAM,0); //设置该套接字为广播类型， setsockopt(s,SOL_SOCKET,SO_BROADCAST,(char FAR *)&optval,sizeof(optval)); bind(s,(sockaddr *)&a,sizeof(sockaddr_in)); char buf[256]; while(1) {//从广播地址接收消息，注意用来绑定的地址和接收消息的地址是不一样的 recvfrom(s,buf,256,0,(struct sockaddr FAR *)&from,(int FAR *)&fromlength); Sleep(2000); printf("%s\n",buf); ZeroMemory(buf,256); } }