UDP客户端不与服务器连接

Question

我与客户和服务器建立聊天。但客户端无法连接到服务器。请告诉我有什么问题？

服务器代码

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>  
#include <stdlib.h>  
#include <string.h>
#define BUFOR 512


int main(int argc, char *argv[])  
 { 
 int fd, serverLength, cLength;

 struct sockaddr_in serverAddr, c_addr[2], clientAddr;  
 cLength = sizeof(clientAddr);
 char buf[BUFOR];  
 int clients = 0;
 int c_port[2];

 if(argc != 2)  
     {  
        printf(" portu");  
        exit(1);  
     } 

 uint16_t port = atoi( argv[ 1 ] ); 


 if ((fd = socket(AF_INET, SOCK_DGRAM, 0))==-1)
     {
        perror("Blad socket");
        exit(1); 
     }


 bzero((char*) &serverAddr, sizeof(serverAddr));  
 serverAddr.sin_family = AF_INET;  
 serverAddr.sin_addr.s_addr = htonl(INADDR_ANY); 
 serverAddr.sin_port = htons(port);  
 serverLength = sizeof(serverAddr);



 if (bind(fd, (struct sockaddr* ) &serverAddr, serverLength)==-1)
     {
         perror("Blad bind");
         exit(1); 
     }


 for(;;)
    {
         printf("Receiving...\n");

         if (recvfrom(fd, buf, BUFOR, 0, (struct sockaddr*)&clientAddr, &cLength)==-1)  
             {
                  perror("Blad recvfrom");
                  exit(1); 
             }

         if (clients==0) 

            { 
                 c_addr[0] = clientAddr;

                 c_port[0] = ntohs(c_addr[0].sin_port);

                 clients++;

                 printf("Client 0 was connected. Port: %d\n",c_port[0]);

                 sendto(fd, "I am only one cleint.", 24, 0, (struct sockaddr*)&clientAddr, cLength);
            }else if(clients==1)
            {

                 if (c_port[0]==ntohs(clientAddr.sin_port))
                     {

                         sendto(fd, "I am only one client.", 24, 0, (struct sockaddr*)&c_addr[0], sizeof(c_addr[0]));
                         printf("One cleint\n");
                     }else
                     {

                          c_addr[1] = clientAddr;
                          c_port[1] = ntohs(c_addr[1].sin_port);
                          clients++;
                          printf("Second cleint\n");
                          sendto(fd, buf, BUFOR, 0, (struct sockaddr*)&c_addr[0], sizeof(c_addr[0]));
                      }

            }else
            {


               if (c_port[0]==ntohs(clientAddr.sin_port))
               {

                          printf("Sending emssage for client 1\n");
                          if (sendto(fd, buf, BUFOR, 0, (struct sockaddr*)&c_addr[1], sizeof(c_addr[0]))==-1)
                              {
                                   clients--;
                                   perror("Error senttoen");
                              }
               }else
               {

                          printf("Sending message for client 0\n");
                          if (sendto(fd, buf, BUFOR, 0, (struct sockaddr*)&c_addr[0], sizeof(c_addr[1]))==-1)
                              {
                                   clients--;
                                   perror("Blad senttoen");
                               }
                }


              }



      }

     close(fd);  
      return 0;

 }

客户端代码

#include <arpa/inet.h>  
#include <netinet/in.h>  
#include <stdio.h>  
#include <sys/types.h>  
#include <sys/socket.h>  
#include <unistd.h>  
#include <stdlib.h>  
#include <string.h>
#include <sys/wait.h>
#include <signal.h>

#define BUFLEN 512    


int main(int argc, char *argv[])  
 {  
      struct sockaddr_in serv_addr;  
      int sockfd;
      socklen_t slen;
      slen=sizeof(serv_addr);  
      char buf[BUFLEN]; 

 if(argc != 3)  
   {  
       printf("Usage : %s <Server-IP>\n",argv[2]);  
       exit(0);  
   } 



 if ((sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1)  
   {
       perror("Socket Error");
       exit(1);
   }
 uint16_t port = atoi( argv[ 1 ] ); 

 bzero(&serv_addr, sizeof(serv_addr));  
 serv_addr.sin_family = AF_INET;  
 serv_addr.sin_port = htons(port);  
 serv_addr.sin_addr.s_addr = inet_addr(argv[2]);


 while(1)
   {
     bzero(buf,BUFLEN);
     printf("Attempting to READ to socket %d: ",sockfd);
     fflush(stdout);

     if(recvfrom(sockfd, buf, BUFLEN, 0, (struct sockaddr*)&serv_addr, &slen)==-1)  
        {
            perror("Blad bind");
            exit(1); 
        }
      printf("The message from the server is: %s \n",buf);
      printf("Please enter the message to send: ");
      bzero(buf,BUFLEN);
      fgets(buf,BUFLEN,stdin);
      printf("Attempting to write to socket %d: ",sockfd);
      fflush(stdout);

      if (sendto(sockfd, buf, BUFLEN, 0, (struct sockaddr*)&serv_addr, slen)==-1)
           {
               perror("Blad bind");
               exit(1); 
           }

   }


 close(sockfd);  
 return 0;



}

似乎sendto被recvfrom阻止，但我不知道如何在无限循环中创建它。