Server Client return IP Adress

[bigmen2007]

Hello, I have an excersise in my university school. The excersise says that we need a server and a client written in C where they communicate and the server returns to client the IP address of client and print it to the screen. The two codes that I found are those:

Server:

/* tcpserver.c */

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


int main()
{
        int sock, connected, bytes_recieved , true = 1;  
        char send_data [1024] , recv_data[1024];       

        struct sockaddr_in server_addr,client_addr;    
        int sin_size;
        
        if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("Socket");
            exit(1);
        }

        if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&true,sizeof(int)) == -1) {
            perror("Setsockopt");
            exit(1);
        }
        
        server_addr.sin_family = AF_INET;         
        server_addr.sin_port = htons(5000);     
        server_addr.sin_addr.s_addr = INADDR_ANY; 
        bzero(&(server_addr.sin_zero),8); 

        if (bind(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr))
                                                                       == -1) {
            perror("Unable to bind");
            exit(1);
        }

        if (listen(sock, 5) == -1) {
            perror("Listen");
            exit(1);
        }
		
	printf("\nTCPServer Waiting for client on port 5000");
        fflush(stdout);


        while(1)
        {  

            sin_size = sizeof(struct sockaddr_in);

            connected = accept(sock, (struct sockaddr *)&client_addr,&sin_size);

            printf("\n I got a connection from (%s , %d)",
                   inet_ntoa(client_addr.sin_addr),ntohs(client_addr.sin_port));

            while (1)
            {
              printf("\n SEND (q or Q to quit) : ");
              gets(&client_addr);
              
              if (strcmp(&client_addr , "q") == 0 || strcmp(&client_addr, "Q") == 0)
              {
                send(connected, &client_addr ,strlen(&client_addr), 0); 
                close(connected);
                break;
              }
               
              else
                 send(connected, &client_addr ,strlen(&client_addr), 0);  

              bytes_recieved = recv(connected,recv_data,1024,0);

              recv_data[bytes_recieved] = '\0';

              if (strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
              {
                close(connected);
                break;
              }

              else 
              printf("\n RECIEVED DATA = %s " , recv_data);
              fflush(stdout);
            }
        }       

      close(sock);
      return 0;
}

Client:

/* tcpclient.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()

{

        int sock, bytes_recieved;  
        char send_data[1024],recv_data[1024];
        struct hostent *host;
        struct sockaddr_in server_addr;  

        host = gethostbyname("127.0.0.1");

        if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("Socket");
            exit(1);
        }

        server_addr.sin_family = AF_INET;     
        server_addr.sin_port = htons(5000);   
        server_addr.sin_addr = *((struct in_addr *)host->h_addr);
        bzero(&(server_addr.sin_zero),8); 

        if (connect(sock, (struct sockaddr *)&server_addr,
                    sizeof(struct sockaddr)) == -1) 
        {
            perror("Connect");
            exit(1);
        }

        while(1)
        {
        
          bytes_recieved=recv(sock,recv_data,1024,0);
          recv_data[bytes_recieved] = '\0';
 
          if (strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
          {
           close(sock);
           break;
          }

          else
           printf("\nRecieved data = %s " , recv_data);
           
           printf("\nSEND (q or Q to quit) : ");
           gets(send_data);
           
          if (strcmp(send_data , "q") != 0 && strcmp(send_data , "Q") != 0)
           send(sock,send_data,strlen(send_data), 0); 

          else
          {
           send(sock,send_data,strlen(send_data), 0);   
           close(sock);
           break;
          }
        
        }   
return 0;
}

Thanks in advance.

[tabstop]

Thanks in advance for what?

[bigmen2007]

Thanks in advance for what?

I need to put into the code some commands so the server will return to client the ip adress of client, but I don't know what are those commands and where to put them.

[msh]

Thanks in advance for what?

Don't look a gift horse in the mouth.

[msh]

I need to put into the code some commands so the server will return to client the ip adress of client, but I don't know what are those commands and where to put them.

Lets see if I got this right. You copy-pasted some code. Now you want us to adjust it to do what you need. And then you will present it for evaluation as something you've done yourself?

You're either very bold or very stupid.

[tabstop]

Do you see the IP address of client printed out by the program, somewhere?

Do you see data sent to the client, somewhere?

Can you combine those two pieces of information?

Also, if you found this somewhere, be sure to cite your sources, and for goodness' sake, don't use gets.

[bigmen2007]

Lets see if I got this right. You copy-pasted some code. Now you want us to adjust it to do what you need. And then you will present it for evaluation as something you've done yourself?

You're either very bold or very stupid.

I've tried several combinations without resault. This code I found was given by my professor, so I 've put the original one because I don't want to confuse you with my stupidities.

[bigmen2007]

Do you see the IP address of client printed out by the program, somewhere?

Do you see data sent to the client, somewhere?

Can you combine those two pieces of information?

Also, if you found this somewhere, be sure to cite your sources, and for goodness' sake, don't use gets.

Yes, server prints to screen the IP adress of client but I don't see data sent to the client. If I type something to server it returns it to client but only manualy. I tried to make server to send the IP to client without any success. Only a type of ip was returned to client like 236.7.195.191. The IP shown on server is 127.0.0.1

[tabstop]

Yes, server prints to screen the IP adress of client but I don't see data sent to the client. If I type something to server it returns it to client but only manualy.

Well, yes, but that command that sends will send no matter where you put it in the program....

I tried to make server to send the IP to client without any success. Only a type of ip was returned to client like 236.7.195.191. The IP shown on server is 127.0.0.1

I'm confused here. What's wrong with 236.7.195.191? For that matter, what's right about 127.0.0.1? That's just a loopback address, and even if you're looking for a local network IP is not what you want.

[bigmen2007]

I'm confused here. What's wrong with 236.7.195.191? For that matter, what's right about 127.0.0.1? That's just a loopback address, and even if you're looking for a local network IP is not what you want.

So the IP adress shown on the client is right?

[tabstop]

If you are 236.7.195.191, then sure. That appears to be a reserved-for-multicast address, but I personally have never been really clear on what's going to be a valid address from that group, so I don't know if that's bogus or not. "ifconfig -a" should tell you what your machine thinks its network address is, so that may give you a start.

[bigmen2007]

If you are 236.7.195.191, then sure. That appears to be a reserved-for-multicast address, but I personally have never been really clear on what's going to be a valid address from that group, so I don't know if that's bogus or not. "ifconfig -a" should tell you what your machine thinks its network address is, so that may give you a start.

Thanks for all the info until now. I have another question, how can I find that I am this adress and why it changes every time I run the program?

[tabstop]

Thanks for all the info until now. I have another question, how can I find that I am this adress and why it changes every time I run the program?

"ifconfig -a" should tell you what your machine thinks its address is (assuming you are on a *nix machine). How are you generating the address in your program?