/******************************************************************************//* This file has been written by Sergio Perez Alca駃z <serpeal@upvnet.upv.es> *//*            Departamento de Inform醫ica de Sistemas y Computadores          *//*            Universidad Polit閏nica de Valencia                             *//*            Valencia (Spain)                                                *//*            Date: April 2003                                                *//******************************************************************************/#include <linux/module.h>#include <linux/kernel.h>#include "netdb.h"#include "ares.h"#include "ares_dns.h"#include "memcopy.h"#include "lwip/sys.h"#include "lwip/ip_addr.h"#include "lwip/inet.h"#include "lwip/sockets.h"#include <rtl_printf.h>#ifndef INADDR_NONE#define	INADDR_NONE 0xffffffff#endif#define QUESTION "cybeles.disca.upv.es"#define DNS_SERVER_ADDR "158.42.4.4"static void dns_client_callback(void *arg, int status, struct hostent *host){  struct in_addr addr;  char *mem, **p;  if (status != ARES_SUCCESS)    {      rtl_printf("%s: %s\n", (char *) arg, ares_strerror(status, &mem));      ares_free_errmem(mem);      return;    }  for (p = host->h_addr_list; *p; p++)    {      char *address = "                                  ";      memcopy(&addr, *p, sizeof(struct in_addr));      address = inet_ntoa(addr);      rtl_printf("%s: %s\n", host->h_name, address);    }}/*-----------------------------------------------------------------------------------*/static void dns_client(void *arg){  ares_channel channel;  int status, nfds;  fd_set read_fds, write_fds;  struct timeval *tvp, tv;  char *errmem;  struct in_addr addr;  struct in_addr ns1;  struct ares_options options;  inet_aton(DNS_SERVER_ADDR,&ns1);  options.servers = &ns1;  options.nservers = 1;  options.flags = ARES_FLAG_USEVC;  status = ares_init_options(&channel, &options, ARES_OPT_SERVERS | ARES_OPT_FLAGS);  if (status != ARES_SUCCESS)    {      rtl_printf("ares_init: %s\n", ares_strerror(status, &errmem));            ares_free_errmem(errmem);      sys_thread_exit();    }      addr.s_addr = inet_addr(QUESTION);  if (addr.s_addr == INADDR_NONE){    ares_gethostbyname(channel, QUESTION, AF_INET, dns_client_callback, QUESTION);  }else{      ares_gethostbyaddr(channel, &addr, sizeof(addr), AF_INET, dns_client_callback,			 QUESTION);  }  /* Wait for all queries to complete. */  while (1)    {      FD_ZERO(&read_fds);      FD_ZERO(&write_fds);      nfds = ares_fds(channel, &read_fds, &write_fds);      if (nfds == 0)	break;      tvp = ares_timeout(channel, NULL, &tv);      select(nfds, &read_fds, &write_fds, NULL, tvp);      ares_process(channel, &read_fds, &write_fds);    }    ares_destroy(channel);}/*-----------------------------------------------------------------------------------*/int init_module(void){  printk("\n\nDNS client module inserted.\n\n");   sys_thread_new(dns_client, NULL, 0);  return 0;}/*-----------------------------------------------------------------------------------*/void cleanup_module(void){  printk("\n\nDNS client module removed.\n\n"); }