c编写的RIP协议源程序

用C写的rip协议 这是其中的广播request程序片段： void RouteInit() { int i,optval=0,length,error; routeNum = 0; // init local socket address and ip address GetLocalIP(); // init route table items for(i = 0; i < MAX_NUM; i++) { SetRouteEntry(&routeTable[i].routeInfo,"0.0.0.0",0,0); routeTable[i].isvalid = 0; routeTable[i].timer = 0; routeTable[i].statue = 0; inet_aton("0,0,0,0",&routeTable[i].sourceIPAddr); } // init request packet SetRoutePacket(&reqPacket,REQUEST); SetRouteEntry(&reqPacket.routeEntry[0],"0.0.0.0",0,16); // init response packet SetRoutePacket(&resPacket,RESPONSE); recvSockAddr.sin_family = AF_INET; recvSockAddr.sin_port = htons(PORT); recvSockAddr.sin_addr.s_addr = htonl(INADDR_ANY); sendSockAddr.sin_family = AF_INET; sendSockAddr.sin_port = htons(PORT); // inet_aton("240.255.255.255",&sendSockAddr.sin_addr); sendSockAddr.sin_addr.s_addr = htonl(INADDR_ANY); EntryInit(); sock = socket(AF_INET,SOCK_DGRAM,0); if(sock<0) { printf("cannot create a socket!\n"); exit(1); } if(setsockopt(sock,SOL_SOCKET,SO_BROADCAST,&optval,sizeof(int)) != 0) { printf("cannot broadcast!\n"); close(sock); exit(1); } if(bind(sock,(struct sockaddr*)&recvSockAddr,sizeof(recvSockAddr))<0) { printf("cannot bind to port\n"); close(sock); exit(1); } length=sizeof recvSockAddr; getsockname(sock,(struct sockaddr*)&recvSockAddr,&length); printf("Port %d is opened. Listen for packet...\n",ntohs(recvSockAddr.sin_port)); FD_ZERO(&fdSet); FD_SET(sock,&fdSet); error = sendto(sock,&reqPacket,4+sizeof(struct ROUTE_ENTRY),0,(struct sockaddr*)(&sendSockAddr),sizeof(struct sockaddr)); if(