hostent modification

[Ryan Rathje]

I'm trying to write a custom dns program that instead of calling the
"gethostbyname(query)" to resolve an IP, it calls my get_rand_ip(query)
function.  Now, the background is thus:

 

            I'm trying to have our gateway pick a random IP and send it back
to the client that requested the query (say client asks for www.google.com
<http://www.google.com/> , and custom dns programs returns 123.123.123.123).
This may be confusing as to why I want to do this, think simulating the
Internet within a controlled environment.  I'm able to fill in all parts of
the hostent struct except for **h_addr_list.

 

struct hostent {

            

            char      *h_name;

            char      **h_aliases;

            int         h_addrtype;

            int         h_length;

            char      **h_addr_list;

}

 

So to make this mess a little clearer, how to do "inject" an (random) IP
into the variable "**h_addr_list"?  Here is a snippet of my code:

 

#include <string.h>

#include <stdlib.h>

#include <stdio.h>

#include <netdb.h>

 

struct hostent get_rand_ip(char *query);

 

struct hostent get_rand_ip(char *query)

{

struct hostent myHost;

char ch[] = "123.122.121.111";

 

myHost.h_name = query;

myHost.h_aliases = NULL;

myHost.h_addrtype = AF_INET;

myHost.h_length = 4;

myHost.h_addr_list = (char *) ch;

 

return myHost;

}

 

Lastly, I what would the corresponding printf statement be for verifying
that my random ip did get assigned properly to h_addr_list?  Thanks to all
that took the time to read this.