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libcares/ares_getaddrinfo.c  view on Meta::CPAN

      else
        {
          port = lookup_service(service, 0);
          if (!port)
            {
              port = (unsigned short)strtoul(service, NULL, 0);
              if (!port)
                {
                  callback(arg, ARES_ESERVICE, 0, NULL);
                  return;
                }
            }
        }
    }
  if (fake_addrinfo(name, port, hints, callback, arg))
    return;

  /* Allocate and fill in the host query structure. */
  hquery = ares_malloc(sizeof(struct host_query));
  if (!hquery)
    {
      callback(arg, ARES_ENOMEM, 0, NULL);
      return;
    }
  hquery->name = ares_strdup(name);
  if (!hquery->name)
    {
      ares_free(hquery);
      callback(arg, ARES_ENOMEM, 0, NULL);
      return;
    }
  hquery->port = port;
  hquery->channel = channel;
  hquery->hints = *hints;
  hquery->sent_family = -1; /* nothing is sent yet */
  hquery->callback = callback;
  hquery->arg = arg;
  hquery->remaining_lookups = channel->lookups;
  hquery->timeouts = 0;
  hquery->ai = NULL;
  hquery->cname = NULL;
  
  /* Start performing lookups according to channel->lookups. */
  next_lookup(hquery, ARES_ECONNREFUSED /* initial error code */);
}

static void next_lookup(struct host_query *hquery, int status_code)
{
  const char *p;
  int status = status_code;

  for (p = hquery->remaining_lookups; *p; p++)
    {
      switch (*p)
        {
        case 'b':
          /* DNS lookup */
          hquery->remaining_lookups = p + 1;
          if ((hquery->hints.ai_family == AF_INET6) ||
              (hquery->hints.ai_family == AF_UNSPEC)) {
            /* if inet6 or unspec, start out with AAAA */
            hquery->sent_family = AF_INET6;
            ares_search(hquery->channel, hquery->name, C_IN, T_AAAA,
                        host_callback, hquery);
          }
          else {
            hquery->sent_family = AF_INET;
            ares_search(hquery->channel, hquery->name, C_IN, T_A,
                        host_callback, hquery);
          }
          return;

        case 'f':
          /* Host file lookup */
          status = file_lookup(hquery);

          /* this status check below previously checked for !ARES_ENOTFOUND,
             but we should not assume that this single error code is the one
             that can occur, as that is in fact no longer the case */
          if (status == ARES_SUCCESS)
            {
              end_hquery(hquery, status);
              return;
            }
          status = status_code;   /* Use original status code */
          break;
        }
    }
  end_hquery(hquery, status);
}

static int file_lookup(struct host_query *hquery)
{
  FILE *fp;
  int error;
  int status;

#ifdef WIN32
  char PATH_HOSTS[MAX_PATH];
  win_platform platform;

  PATH_HOSTS[0] = '\0';

  platform = ares__getplatform();

  if (platform == WIN_NT) {
    char tmp[MAX_PATH];
    HKEY hkeyHosts;

    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0, KEY_READ,
                     &hkeyHosts) == ERROR_SUCCESS)
    {
      DWORD dwLength = MAX_PATH;
      RegQueryValueEx(hkeyHosts, DATABASEPATH, NULL, NULL, (LPBYTE)tmp,
                      &dwLength);
      ExpandEnvironmentStrings(tmp, PATH_HOSTS, MAX_PATH);
      RegCloseKey(hkeyHosts);
    }
  }
  else if (platform == WIN_9X)
    GetWindowsDirectory(PATH_HOSTS, MAX_PATH);