Question

Instructions

• Write a Client/Server application to do the following​
• Client​
  • Take in IP address and Port as command line arguments​
  • Connect to Server​
  • Start "infinite loop"​
    • Take in message from command line​
    • Convert it to the packet form from last lab​
      • Instead of an array, store packet in a char array (string) so it can be easily sent​
    • Print out packet to terminal​
    • Send packet to server​
    • Print out reply from server
  • End "infinite loop"
• Server
  • Create connection on the IP address/port​ (obtain these from command line args)
  • Start infinite loop​
    • Wait for messages​
    • When a message is received​
      • Check to see if it is valid, including the checksum calculation​
      • If valid​
        • Print out message to terminal​
        • Send message back to client saying message received​
      • If not valid​
        • Send message back to client saying message rejected​
    • End infinite loop

Answer 1

//*********************************TCP_client.c********************************//

#include <sys/socket.h>

#include <sys/types.h>

#include <netinet/in.h>

#include <netdb.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <errno.h>

int main()

{

        char sendMessage[512],receiveMessage[512];

        int sock, result;

        struct hostent *host;

        struct sockaddr_in serverAdd;

        host = gethostbyname(“xxx.xx.xx.xx”);     

        if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)

            {

            perror(“Socket creation failed”);

exit(1);

        }

        serverAdd.sin_family = AF_INET;    

        serverAdd.sin_port = htons(5000);  

        serverAdd.sin_addr = *((struct in_addr *)host->h_addr);

        bzero(&(serverAdd.sin_zero),8);

        if (connect(sock, (struct sockaddr *)&serverAdd, sizeof(struct sockaddr)) == -1)

        {

            perror(“Connection failed”);

            exit(1);

        }

        while(1)

        {

                        result = recv(sock,receiveMessage,1024,0);

                        receiveMessage[result] = ”;

                        printf(“nRecieved Message: %s ” , receiveMessage);

                        printf(“nSEND The message: “);

                        fgets(sendMessage,512,stdin);

                        send(sock,sendMessage,strlen(sendMessage), 0);

        }  

        return 0;

}

//*********************************TCP_client.c********************************//

Server side program:

//*********************************TCP_server.c*******************************//

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <errno.h>

int main()

{

         char sendMessage[1024] ,receiveMessage[1024];

         int sock, connected, result;        

        struct sockaddr_in serverAdd, clientAdd;   

        int length;

        if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)

        {

            perror(“Socket creation is failed”);

            exit(1);

        }

        if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&1,sizeof(int)) == -1)

       {

            perror(“Set socket option”);

            exit(1);

        }

       

        serverAdd.sin_family = AF_INET;        

        serverAdd.sin_port = htons(5000);

serverAdd.sin_addr.s_addr = INADDR_ANY;

        bzero(&(serverAdd.sin_zero),8);

       if (bind(sock, (struct sockaddr *)&serverAdd, sizeof(struct sockaddr))== -1)

       {

            perror(“Unable to bind”);

            exit(1);

        }

        if (listen(sock, 3) == -1)

       {

            perror(“Listen”);

            exit(1);

        }

        printf(“TCPServer Waiting for client connectionn”);

        fflush(stdout);

        while(1)

        {

            length = sizeof(struct sockaddr_in);

            connected = accept(sock,(struct sockaddr *)&clientAdd,&length);

            printf(“Server is connected with IP address %s and port %d    n”,inet_ntoa(clientAdd.sin_addr),ntohs(clientAdd.sin_port));

           

while (1)

            {

                        printf(” SEND the message : “);

                        fgets(sendMessage,100,stdin);

                        send(connected, sendMessage,strlen(sendMessage), 0);

result = recv(connected,receiveMessage,512,0);

receiveMessage[result] = ”;

printf(“Received message : %s n” , receiveMessage);

                        fflush(stdout);

            }

        }      

        return 0;

}

//*********************************TCP_server.c*******************************/
write machine ip in host = gethostbyname(“xxx.xx.xx.xx”); run both program in same machine .

first compile the c code gcc -c clinet.c and gcc -c server.c then run the compiled files program .

./client in one terminal anf ./server in another terminal .

hurray