计算机网络实验二.docx

1、计算机网络实验二实验报告学院（系）名称：计算机与通信工程学院姓名Sky学号专业计算机科学与技术班级2班实验名称基于TCP/UDP的Socket编程课程名称计算机网络课程代码0662016实验时间2016年4月18日14:00-15:40实验地点7-219批改意见成绩教师签字： 1. 实验目的了解套接字(socket)实现原理。通过编成理解TCP、UDP原理，加深对传输层的功能理解2. 实验环境 VC+6.03. 实验过程记录（源程序、测试用例、测试结果及心得体会等）传送字符串：Clinet端源码：#define WIN32_LEAN_AND_MEAN#include #include #inc

2、lude #include #pragma comment(lib, ws2_32.lib) #define DEFAULT_PORT 2007#define DEFAULT_PROTO SOCK_STREAM void Usage(char *progname) fprintf(stderr,Usage: %s -p protocol -n server name/IP -e port_num -l iterationsn, progname); fprintf(stderr,Where:ntprotocol is one of TCP or UDPn); fprintf(stderr,t-

3、 server is the IP address or name of servern); fprintf(stderr,t- port_num is the port to listen onn); fprintf(stderr,t- iterations is the number of loops to execute.n); fprintf(stderr,t- (-l by itself makes client run in an infinite loop,n); fprintf(stderr,t- Hit Ctrl-C to terminate it)n); fprintf(s

4、tderr,t- The defaults are TCP , localhost and 2007n); WSACleanup(); exit(1);int main(int argc, char *argv) char Buffer128; char *server_name= localhost; unsigned short port = DEFAULT_PORT; int retval, loopflag = 0; int i, loopcount, maxloop=-1; unsigned int addr; int socket_type = DEFAULT_PROTO; str

5、uct sockaddr_in server; struct hostent *hp; WSADATA wsaData; SOCKET conn_socket; if (argc 1) for(i=1; ih_addr, hp-h_length); server.sin_family = hp-h_addrtype; server.sin_port = htons(port); conn_socket = socket(AF_INET, socket_type, 0); /* Open a socket */ if (conn_socket h_name); if (connect(conn_

6、socket, (struct sockaddr*)&server, sizeof(server) = SOCKET_ERROR) fprintf(stderr,Client: connect() failed: %dn, WSAGetLastError(); WSACleanup(); return -1; else printf(Client: connect() is OK.n); / Test sending some string loopcount = 0; while(1) wsprintf(Buffer,This is a test message from client #%

7、d, loopcount+); retval = send(conn_socket, Buffer, sizeof(Buffer), 0); if (retval = SOCKET_ERROR) fprintf(stderr,Client: send() failed: error %d.n, WSAGetLastError(); WSACleanup(); return -1; else printf(Client: send() is OK.n); printf(Client: Sent data %sn, Buffer); retval = recv(conn_socket, Buffe

8、r, sizeof(Buffer), 0); if (retval = SOCKET_ERROR) fprintf(stderr,Client: recv() failed: error %d.n, WSAGetLastError(); closesocket(conn_socket); WSACleanup(); return -1; else printf(Client: recv() is OK.n); / We are not likely to see this with UDP, since there is no / connection established. if (ret

9、val = 0) printf(Client: Server closed connection.n); closesocket(conn_socket); WSACleanup(); return -1; printf(Client: Received %d bytes, data %s from server.n, retval, Buffer); if (!loopflag) printf(Client: Terminating connection.n); break; else if (loopcount = maxloop) & (maxloop 0) break; closeso

10、cket(conn_socket); WSACleanup();return 0;Server端源码：#define WIN32_LEAN_AND_MEAN#include #include #include #include #pragma comment(lib, ws2_32.lib)#define DEFAULT_PORT 2007/ default TCP socket type#define DEFAULT_PROTO SOCK_STREAMvoid Usage(char *progname) fprintf(stderr,Usage: %s -p protocol -e port

11、_num -i ip_addressn, progname); fprintf(stderr,Where:nt- protocol is one of TCP or UDPn); fprintf(stderr,t- port_num is the port to listen onn); fprintf(stderr,t- ip_address is the ip address (in dottedn); fprintf(stderr,t decimal notation) to bind to. But it is not useful here.n); fprintf(stderr,t-

12、 Hit Ctrl-C to terminate server program.n); fprintf(stderr,t- The defaults are TCP, 2007 and INADDR_ANY.n); WSACleanup(); exit(1); int main(int argc, char *argv) char Buffer128; char *ip_address= NULL; unsigned short port=DEFAULT_PORT; int retval; int fromlen; int i; int socket_type = DEFAULT_PROTO;

13、 struct sockaddr_in local, from; WSADATA wsaData; SOCKET listen_socket, msgsock; /* Parse arguments, if there are arguments supplied */ if (argc 1) for(i=1; iargc; i+) / switches or options. if (argvi0 = -) | (argvi0 = /) / Change to lower.if any switch(tolower(argvi1) / if -p or /p case p: if (!str

14、icmp(argvi+1, TCP) socket_type = SOCK_STREAM; else if (!stricmp(argvi+1, UDP) socket_type = SOCK_DGRAM; else Usage(argv0); i+; break; / if -i or /i, for server it is not so useful. case i: ip_address = argv+i; break; / if -e or /e case e: port = atoi(argv+i); break; / No match. default: Usage(argv0)

15、; break; else Usage(argv0); / Request Winsock version 2.2 if (retval = WSAStartup(0x202, &wsaData) != 0) fprintf(stderr,Server: WSAStartup() failed with error %dn, retval); WSACleanup(); return -1; else printf(Server: WSAStartup() is OK.n); if (port = 0) Usage(argv0); local.sin_family = AF_INET; loc

16、al.sin_addr.s_addr = (!ip_address) ? INADDR_ANY:inet_addr(ip_address); /* Port MUST be in Network Byte Order */ local.sin_port = htons(port); / TCP socket listen_socket = socket(AF_INET, socket_type,0); if (listen_socket = INVALID_SOCKET) fprintf(stderr,Server: socket() failed with error %dn, WSAGet

17、LastError(); WSACleanup(); return -1; else printf(Server: socket() is OK.n); / bind() associates a local address and port combination with the socket just created. / This is most useful when the application is a / server that has a well-known port that clients know about in advance. if (bind(listen_

18、socket, (struct sockaddr*)&local, sizeof(local) = SOCKET_ERROR) fprintf(stderr,Server: bind() failed with error %dn, WSAGetLastError(); WSACleanup(); return -1; else printf(Server: bind() is OK.n); / So far, everything we did was applicable to TCP as well as UDP. / However, there are certain steps t

19、hat do not work when the server is / using UDP. We cannot listen() on a UDP socket. if (socket_type != SOCK_DGRAM) if (listen(listen_socket,5) = SOCKET_ERROR) fprintf(stderr,Server: listen() failed with error %dn, WSAGetLastError(); WSACleanup(); return -1; else printf(Server: listen() is OK.n); pri

20、ntf(Server: %s: Im listening and waiting connectionnon port %d, protocol %sn, argv0, port, (socket_type = SOCK_STREAM)?TCP:UDP); while(1) fromlen =sizeof(from); / accept() doesnt make sense on UDP, since we do not listen() if (socket_type != SOCK_DGRAM) msgsock = accept(listen_socket, (struct sockad

21、dr*)&from, &fromlen); if (msgsock = INVALID_SOCKET) fprintf(stderr,Server: accept() error %dn, WSAGetLastError(); WSACleanup(); return -1; else printf(Server: accept() is OK.n); printf(Server: accepted connection from %s, port %dn, inet_ntoa(from.sin_addr), htons(from.sin_port) ; else msgsock = list

22、en_socket; / In the case of SOCK_STREAM, the server can do recv() and send() on / the accepted socket and then close it. / However, for SOCK_DGRAM (UDP), the server will do recvfrom() and sendto() in a loop. if (socket_type != SOCK_DGRAM) retval = recv(msgsock, Buffer, sizeof(Buffer), 0); else retva

23、l = recvfrom(msgsock,Buffer, sizeof(Buffer), 0, (struct sockaddr *)&from, &fromlen); printf(Server: Received datagram from %sn, inet_ntoa(from.sin_addr); if (retval = SOCKET_ERROR) fprintf(stderr,Server: recv() failed: error %dn, WSAGetLastError(); closesocket(msgsock); continue; else printf(Server:

24、 recv() is OK.n); if (retval = 0) printf(Server: Client closed connection.n); closesocket(msgsock); continue; printf(Server: Received %d bytes, data %s from clientn, retval, Buffer); printf(Server: Echoing the same data back to client.n); if (socket_type != SOCK_DGRAM) retval = send(msgsock, Buffer,