resolv.c

linux内核

#ident "$Id$"
/* ----------------------------------------------------------------------- *
 *   
 *   Copyright 2004 H. Peter Anvin - All Rights Reserved
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * resolv.c
 *
 * Resolve an IP address
 */

#include <string.h>
#include <stdio.h>
#include <console.h>
#include <stdlib.h>
#include <com32.h>

uint32_t resolv(const char *name)
{
  com32sys_t reg;

  strcpy((char *)__com32.cs_bounce, name);

  memset(&reg, 0, sizeof reg);
  reg.eax.w[0] = 0x0010;
  reg.ebx.w[0] = OFFS(__com32.cs_bounce);
  reg.es       = SEG(__com32.cs_bounce);

  __intcall(0x22, &reg, &reg);

  if ( reg.eflags.l & EFLAGS_CF )
    return 0;
  else
    return reg.eax.l;
}

int main(int argc, char *argv[])
{
  uint32_t ip;

  openconsole(&dev_null_r, &dev_stdcon_w);

  if ( argc < 2 ) {
    fputs("Usage: resolv hostname\n", stderr);
    exit(1);
  }

  ip = resolv(argv[1]);

  if ( ip ) {
    printf("%s = %u.%u.%u.%u\n", argv[1],
	   (ip & 0xff), (ip >> 8) & 0xff,
	   (ip >> 16) & 0xff, (ip >> 24) & 0xff);
  } else {
    printf("%s not found\n", argv[1]);
  }
    
  return 0;
}