udpserver.c

来自「sock编程 一个tcp源码一个udp源码 希望大家喜欢」· C语言 代码 · 共 73 行

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <errno.h>
#include <time.h>

#include "listen_server.h"

const char *DAYTIME_PORT="13111";

int
main(int argc, char *argv[])
{
    int listenfd, n;
    socklen_t addrlen;
    char *myhost;
    char timeStr[256];
    struct sockaddr_storage clientaddr;
    time_t now;
    char b[256];
    char clienthost[NI_MAXHOST];
    char clientservice[NI_MAXSERV];

    myhost="localhost";
    if (argc > 1)
        myhost=argv[1];

    listenfd = listen_server(myhost, DAYTIME_PORT, AF_UNSPEC, SOCK_DGRAM);

    if (listenfd < 0) {
         fprintf(stderr, 
                 "listen_server error:: could not create listening "
                 "socket\n");
         return -1;
    }

    addrlen = sizeof(clientaddr);
    for ( ; ;) {
        n = recvfrom(listenfd,
                     b,
                     sizeof(b),
                     0,
                     (struct sockaddr *)&clientaddr, 
                     &addrlen);

        if (n < 0) 
            continue;

        memset(clienthost, 0, sizeof(clienthost));
        memset(clientservice, 0, sizeof(clientservice));

        getnameinfo((struct sockaddr *)&clientaddr, addrlen,
                    clienthost, sizeof(clienthost),
                    clientservice, sizeof(clientservice),
                    NI_NUMERICHOST);

        printf("Received request from host=[%s] port=[%s]\n",
               clienthost, clientservice);

        memset(timeStr, 0, sizeof(timeStr));
        time(&now);
        sprintf(timeStr, "%s", ctime(&now));

        n = sendto(listenfd, timeStr, sizeof(timeStr), 0, 
                   (struct sockaddr *)&clientaddr, 
                   addrlen);
    }

    return 0;
}