今天段老师在网络软件设计课上布置了一个题目。
要求是windows环境,现在在linux环境下实现。
运行C/S模式的2个程序,使用UDP协议,发送10次,计算平均时延。
服务器程序如下:
#include <sys/socket.h> // for functions for socket #include <netinet/in.h> // for struct sockaddr_in #include <stdlib.h> #include <memory.h> // for memset #include <stdio.h> // for perror #include <errno.h> // for errno #define BUFLEN 100 int main(void) { int listenfd; char buf[BUFLEN]; socklen_t len; struct sockaddr_in serv, cli; if ((listenfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { // use udp perror("socket"); exit(EXIT_FAILURE); } memset(&serv, 0, sizeof(serv)); // clear serv.sin_family = AF_INET; // use IPv4 // Listen any ip address and use network // byte order serv.sin_addr.s_addr = htonl(INADDR_ANY); serv.sin_port = htons(9877); // Listen port 9877 if (bind(listenfd, (struct sockaddr*)&serv, sizeof(serv)) < 0) { // bind the socket to the server address perror("bind"); exit(EXIT_FAILURE); } for ( ; ; ) { len = sizeof(cli); if ((recvfrom(listenfd, buf, BUFLEN, 0, (struct sockaddr*)&cli, &len)) < 0) { // recvfrom the listenfd // put the message into buf // no flags (4th argument 0) // save the client address and length if (errno == EINTR || errno == EAGAIN) continue; perror("recvfrom"); exit(EXIT_FAILURE); } if ((sendto(listenfd, "Got it!", 10, 0, (struct sockaddr*)&cli, len)) < 0) { // send the message back // send message "Got it!" back if (errno == EINTR || errno == EAGAIN) continue; perror("recvfrom"); exit(EXIT_FAILURE); } } return 0; }
#include <sys/socket.h> // for functions for socket #include <arpa/inet.h> // for inet_pton #include <netinet/in.h> // for struct sockaddr_in #include <stdlib.h> #include <memory.h> // for memset #include <stdio.h> // for perror #include <errno.h> // for errno #include <time.h> #define SENDTIMES 10 #define BUFLEN 100 int main(int argc, char* argv[]) { struct sockaddr_in serv; int sockfd; int i; clock_t start, finish; double duration, total = 0; char buf[BUFLEN]; if (argc != 2) { fprintf(stderr, "Usage: ./udpcli <IPADDR>\n"); exit(EXIT_FAILURE); } if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { // use udp perror("socket"); exit(EXIT_FAILURE); } memset(&serv, 0, sizeof(serv)); serv.sin_family = AF_INET; serv.sin_port = htons(9877); if ((inet_pton(AF_INET, argv[1], &serv.sin_addr)) == 0) { // read the string to the structrue perror("inet_pton"); exit(EXIT_FAILURE); } again: if ((connect(sockfd, (struct sockaddr*)&serv, sizeof(serv))) < 0) { // this connect is for catch the // error ICMP packets if (errno == EINTR || errno == EAGAIN) goto again; perror("connect"); exit(EXIT_FAILURE); } for (i = 0; i < SENDTIMES; ++i) { printf("Send %d messages.\n", i + 1); start = clock(); again2: if ((sendto(sockfd, "A message!", 20, 0, (struct sockaddr*)&serv, sizeof(serv))) < 0) { if (errno == EINTR) goto again2; perror("sendto"); exit(EXIT_FAILURE); } again3: if ((recvfrom(sockfd, buf, BUFLEN, 0, NULL, NULL)) < 0) { if (errno == EINTR) goto again3; perror("recvfrom"); exit(EXIT_FAILURE); } finish = clock(); duration = finish - start; printf("Spend time: %fms\n", duration); total += duration; } printf("\nAverage time: %fms\n", total / SENDTIMES); return 0; }
原文地址:http://blog.csdn.net/pdcxs007/article/details/44219955