Thread Structure for Iterative passiveTcp Connection-oriented server pass TCP. cpp-passiveTCP SOCKET passivesock(const char * corst char *. int): application thread passive TCP-create a passive socket for use in a TaP server SOCKET ssive TCP(const char *service, int qlen) Operating return passivesock(service, "tcp", qlen) An example DAyTIME server An example DAyTIME server I/ TOPdtd, cpp-main, TcPdayti nsock. hp struct sin: / the from address of a client service="dayi or port rumber from-address length char*. int): #define QLEN 5 #define WsVERS MAKEWORD(2, 0) rrexit(usage: TaPdaytimed [port]\n): main(nt argc, char *argil An example DAyTIME server An example DAyTIME server (WSAStartuP(WSVERS, &wsadata)l=O TCPdaytimed-do TOP DAyTIME protocol mock= passive TCP(service, QLEN) while(1)( TOPdaytimed(soCKET fd rexitcaccept failed: error number %d\n (void) closesocket(sock) d, pts, strlen(pts), O)6 哈工大计算机学院 李全龙 Network Application Development Server Software Design 31 passiveTCP /* passTCP.cpp - passiveTCP */ #include <winsock.h> SOCKET passivesock(const char *, const char *, int); /*---------------------------------------------------------------------- * passiveTCP - create a passive socket for use in a TCP server *----------------------------------------------------------------------- */ SOCKET passiveTCP(const char *service, int qlen) { return passivesock(service, "tcp", qlen); } 哈工大计算机学院 李全龙 Network Application Development Server Software Design 32 Thread Structure for Iterative Connection-oriented Server server Server application thread Operating system Socket used for Connection requests Socket used for an individual connection 哈工大计算机学院 李全龙 Network Application Development Server Software Design 33 An example DAYTIME server /* TCPdtd.cpp - main, TCPdaytimed */ #include <stdlib.h> #include <winsock.h> #include <time.h> void errexit(const char *, ...); void TCPdaytimed(SOCKET); SOCKET passiveTCP(const char *, int); #define QLEN 5 #define WSVERS MAKEWORD(2, 0) /*------------------------------------------------------------------------ * main - Iterative TCP server for DAYTIME service *------------------------------------------------------------------------ */ void main(int argc, char *argv[]) 哈工大计算机学院 李全龙 Network Application Development Server Software Design 34 An example DAYTIME server { struct sockaddr_in fsin;/* the from address of a client */ char *service = "daytime"; /* service name or port number */ SOCKET msock, ssock; /* master & slave sockets */ int alen; /* from-address length */ WSADATA wsadata; switch (argc) { case 1: break; case 2: service = argv[1]; break; default: errexit("usage: TCPdaytimed [port]\n"); } 哈工大计算机学院 李全龙 Network Application Development Server Software Design 35 An example DAYTIME server if (WSAStartup(WSVERS, &wsadata) != 0) errexit("WSAStartup failed\n"); msock = passiveTCP(service, QLEN); while (1) { alen = sizeof(struct sockaddr); ssock = accept(msock, (struct sockaddr *)&fsin, &alen); if (ssock == INVALID_SOCKET) errexit("accept failed: error number %d\n", GetLastError()); TCPdaytimed(ssock); (void) closesocket(ssock); } } 哈工大计算机学院 李全龙 Network Application Development Server Software Design 36 An example DAYTIME server /*---------------------------------------------------------------------- * TCPdaytimed - do TCP DAYTIME protocol *----------------------------------------------------------------------- */ void TCPdaytimed(SOCKET fd) { char *pts; /* pointer to time string */ time_t now; /* current time */ (void) time(&now); pts = ctime(&now); (void) send(fd, pts, strlen(pts), 0); }