Thread: FreeBSD - getaddrinfo() returning duplicate records...

Here is the code to query for addresses in their numeric form:

Code:

#include <netdb.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <strings.h>
#include <string.h>

int ga_hints( const int, char ** , struct addrinfo * );

int main(int argc, char ** argv){

  struct addrinfo * res, * result, hints;
  int error = 0, host_arg = 0; 
  char host[NI_MAXHOST];
  
  host_arg = ga_hints( argc, argv, &hints );

  if( ( error = getaddrinfo( argv[ host_arg ], NULL, &hints, &result ) ) != 0 ){
    fputs( gai_strerror( error ), stderr );
    exit( -1 ); 
  }

  for( res = result; res != NULL; res = res->ai_next ){

    if( ( error = getnameinfo( res->ai_addr, res->ai_addrlen,  host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST ) ) != 0){
      fputs( gai_strerror( error ), stderr );
      exit( -1 );
    }

    printf(" - %s\n", host);

  }
  

  free(result);

  return 0;

}

// Usage: ./galookup -f [inet4 | inet6 | inet4-6] -h [hostname] 

int ga_hints( const int argc, char ** argv, struct addrinfo * hints ){

  int arg, host;

  bzero( hints, sizeof( *hints) );

  for( arg = 1; arg < argc; arg++ ){
    
    if( !strcmp( "-f", argv[ arg ] ) ){
      
      switch( atoi( argv[ ++arg ] ) ){
	
      case 4:
	hints->ai_family = AF_INET;
	break;

      case 6:
	hints->ai_family = AF_INET6;
	break;

      case 0:
	hints->ai_family = AF_UNSPEC;
	break;
      default:
	printf( "%s is not a valid address family\nDefaulting to AF_UNSPEC...\n", argv[ arg ] );
	hints->ai_family = AF_UNSPEC;
	break;

      } // Switch

    } //if( !strcmp())
    else if( !strcmp( "-h", argv[ arg ] ) )
      host = arg + 1;

  } //for(...)

  return host;

}

and look what happens when I run it:

Code:

$ ./galookup -f 0 -h localhost
 - 127.0.0.1
 - 127.0.0.1
 - 127.0.0.1
 - ::1
 - ::1
 - ::1
$
$
$
$ ./galookup -f 0 -h www.google.com
 - 74.125.227.146
 - 74.125.227.145
 - 74.125.227.144
 - 74.125.227.147
 - 74.125.227.148
 - 74.125.227.144
 - 74.125.227.145
 - 74.125.227.148
 - 74.125.227.147
 - 74.125.227.148
 - 74.125.227.144
 - 74.125.227.145
 - 74.125.227.146
 - 74.125.227.147
 - 74.125.227.146
 - 2001:4860:4002:800::1010
 - 2001:4860:4002:800::1010
 - 2001:4860:4002:800::1010
$ 
$
$ ./galookup -f 0 -h FreeBSD-01v
 - 127.0.0.1
 - 127.0.0.1
 - 127.0.0.1
 - 192.168.0.4
 - 192.168.0.4
 - 192.168.0.4
$

Here's what's in /etc/hosts

Code:

::1			localhost localhost.my.domain
127.0.0.1		localhost FreeBSD-01v localhost.my.domain
192.168.0.4 		FreeBSD-01v

Also, when I do an nslookup, the addresses are totally different for websites but they all seem to work... What gives with that also?