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libcares/ares_init.c  view on Meta::CPAN

    return ARES_ENOMEM;
  }

  now = ares__tvnow();

  /* Set everything to distinguished values so we know they haven't
   * been set yet.
   */
  channel->flags = -1;
  channel->timeout = -1;
  channel->tries = -1;
  channel->ndots = -1;
  channel->rotate = -1;
  channel->udp_port = -1;
  channel->tcp_port = -1;
  channel->ednspsz = -1;
  channel->socket_send_buffer_size = -1;
  channel->socket_receive_buffer_size = -1;
  channel->nservers = -1;
  channel->ndomains = -1;
  channel->nsort = -1;
  channel->tcp_connection_generation = 0;
  channel->lookups = NULL;
  channel->domains = NULL;
  channel->sortlist = NULL;
  channel->servers = NULL;
  channel->sock_state_cb = NULL;
  channel->sock_state_cb_data = NULL;
  channel->sock_create_cb = NULL;
  channel->sock_create_cb_data = NULL;
  channel->sock_config_cb = NULL;
  channel->sock_config_cb_data = NULL;
  channel->sock_funcs = NULL;
  channel->sock_func_cb_data = NULL;
  channel->resolvconf_path = NULL;

  channel->last_server = 0;
  channel->last_timeout_processed = (time_t)now.tv_sec;

  memset(&channel->local_dev_name, 0, sizeof(channel->local_dev_name));
  channel->local_ip4 = 0;
  memset(&channel->local_ip6, 0, sizeof(channel->local_ip6));

  /* Initialize our lists of queries */
  ares__init_list_head(&(channel->all_queries));
  for (i = 0; i < ARES_QID_TABLE_SIZE; i++)
    {
      ares__init_list_head(&(channel->queries_by_qid[i]));
    }
  for (i = 0; i < ARES_TIMEOUT_TABLE_SIZE; i++)
    {
      ares__init_list_head(&(channel->queries_by_timeout[i]));
    }

  /* Initialize configuration by each of the four sources, from highest
   * precedence to lowest.
   */

  status = init_by_options(channel, options, optmask);
  if (status != ARES_SUCCESS) {
    DEBUGF(fprintf(stderr, "Error: init_by_options failed: %s\n",
                   ares_strerror(status)));
    /* If we fail to apply user-specified options, fail the whole init process */
    goto done;
  }
  status = init_by_environment(channel);
  if (status != ARES_SUCCESS)
    DEBUGF(fprintf(stderr, "Error: init_by_environment failed: %s\n",
                   ares_strerror(status)));
  if (status == ARES_SUCCESS) {
    status = init_by_resolv_conf(channel);
    if (status != ARES_SUCCESS)
      DEBUGF(fprintf(stderr, "Error: init_by_resolv_conf failed: %s\n",
                     ares_strerror(status)));
  }

  /*
   * No matter what failed or succeeded, seed defaults to provide
   * useful behavior for things that we missed.
   */
  status = init_by_defaults(channel);
  if (status != ARES_SUCCESS)
    DEBUGF(fprintf(stderr, "Error: init_by_defaults failed: %s\n",
                   ares_strerror(status)));

  /* Generate random key */

  if (status == ARES_SUCCESS) {
    status = init_id_key(&channel->id_key, ARES_ID_KEY_LEN);
    if (status == ARES_SUCCESS)
      channel->next_id = ares__generate_new_id(&channel->id_key);
    else
      DEBUGF(fprintf(stderr, "Error: init_id_key failed: %s\n",
                     ares_strerror(status)));
  }

done:
  if (status != ARES_SUCCESS)
    {
      /* Something failed; clean up memory we may have allocated. */
      if (channel->servers)
        ares_free(channel->servers);
      if (channel->ndomains != -1)
        ares_strsplit_free(channel->domains, channel->ndomains);
      if (channel->sortlist)
        ares_free(channel->sortlist);
      if(channel->lookups)
        ares_free(channel->lookups);
      if(channel->resolvconf_path)
        ares_free(channel->resolvconf_path);
      ares_free(channel);
      return status;
    }

  /* Trim to one server if ARES_FLAG_PRIMARY is set. */
  if ((channel->flags & ARES_FLAG_PRIMARY) && channel->nservers > 1)
    channel->nservers = 1;

  ares__init_servers_state(channel);

  *channelptr = channel;
  return ARES_SUCCESS;
}

/* ares_dup() duplicates a channel handle with all its options and returns a
   new channel handle */
int ares_dup(ares_channel *dest, ares_channel src)
{
  struct ares_options opts;
  struct ares_addr_port_node *servers;
  int non_v4_default_port = 0;
  int i, rc;
  int optmask;

  *dest = NULL; /* in case of failure return NULL explicitly */

  /* First get the options supported by the old ares_save_options() function,
     which is most of them */
  rc = ares_save_options(src, &opts, &optmask);
  if(rc)
  {
    ares_destroy_options(&opts);
    return rc;
  }

  /* Then create the new channel with those options */
  rc = ares_init_options(dest, &opts, optmask);

  /* destroy the options copy to not leak any memory */
  ares_destroy_options(&opts);

  if(rc)
    return rc;

libcares/ares_init.c  view on Meta::CPAN

      channel->timeout = res.retrans * 1000;

    res_ndestroy(&res);
  }
#else
  {
    char *p;
    FILE *fp;
    size_t linesize;
    int error;
    int update_domains;
    const char *resolvconf_path;

    /* Don't read resolv.conf and friends if we don't have to */
    if (ARES_CONFIG_CHECK(channel))
        return ARES_SUCCESS;

    /* Only update search domains if they're not already specified */
    update_domains = (channel->ndomains == -1);

    /* Support path for resolvconf filename set by ares_init_options */
    if(channel->resolvconf_path) {
      resolvconf_path = channel->resolvconf_path;
    } else {
      resolvconf_path = PATH_RESOLV_CONF;
    }

    fp = fopen(resolvconf_path, "r");
    if (fp) {
      while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)
      {
        if ((p = try_config(line, "domain", ';')) && update_domains)
          status = config_domain(channel, p);
        else if ((p = try_config(line, "lookup", ';')) && !channel->lookups)
          status = config_lookup(channel, p, "bind", NULL, "file");
        else if ((p = try_config(line, "search", ';')) && update_domains)
          status = set_search(channel, p);
        else if ((p = try_config(line, "nameserver", ';')) &&
                channel->nservers == -1)
          status = config_nameserver(&servers, &nservers, p);
        else if ((p = try_config(line, "sortlist", ';')) &&
                channel->nsort == -1)
          status = config_sortlist(&sortlist, &nsort, p);
        else if ((p = try_config(line, "options", ';')))
          status = set_options(channel, p);
        else
          status = ARES_SUCCESS;
        if (status != ARES_SUCCESS)
          break;
      }
      fclose(fp);
    }
    else {
      error = ERRNO;
      switch(error) {
      case ENOENT:
      case ESRCH:
        status = ARES_EOF;
        break;
      default:
        DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
                      error, strerror(error)));
        DEBUGF(fprintf(stderr, "Error opening file: %s\n", PATH_RESOLV_CONF));
        status = ARES_EFILE;
      }
    }

    if ((status == ARES_EOF) && (!channel->lookups)) {
      /* Many systems (Solaris, Linux, BSD's) use nsswitch.conf */
      fp = fopen("/etc/nsswitch.conf", "r");
      if (fp) {
        while ((status = ares__read_line(fp, &line, &linesize)) ==
               ARES_SUCCESS)
        {
          if ((p = try_config(line, "hosts:", '\0')) && !channel->lookups)
            (void)config_lookup(channel, p, "dns", "resolve", "files");
        }
        fclose(fp);
      }
      else {
        error = ERRNO;
        switch(error) {
        case ENOENT:
        case ESRCH:
          break;
        default:
          DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
                         error, strerror(error)));
          DEBUGF(fprintf(stderr, "Error opening file: %s\n",
                         "/etc/nsswitch.conf"));
        }

        /* ignore error, maybe we will get luck in next if clause */
        status = ARES_EOF;
      }
    }

    if ((status == ARES_EOF) && (!channel->lookups)) {
      /* Linux / GNU libc 2.x and possibly others have host.conf */
      fp = fopen("/etc/host.conf", "r");
      if (fp) {
        while ((status = ares__read_line(fp, &line, &linesize)) ==
               ARES_SUCCESS)
        {
          if ((p = try_config(line, "order", '\0')) && !channel->lookups)
            /* ignore errors */
            (void)config_lookup(channel, p, "bind", NULL, "hosts");
        }
        fclose(fp);
      }
      else {
        error = ERRNO;
        switch(error) {
        case ENOENT:
        case ESRCH:
          break;
        default:
          DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
                         error, strerror(error)));
          DEBUGF(fprintf(stderr, "Error opening file: %s\n",
                         "/etc/host.conf"));
        }

        /* ignore error, maybe we will get luck in next if clause */
        status = ARES_EOF;
      }
    }

    if ((status == ARES_EOF) && (!channel->lookups)) {
      /* Tru64 uses /etc/svc.conf */
      fp = fopen("/etc/svc.conf", "r");
      if (fp) {
        while ((status = ares__read_line(fp, &line, &linesize)) ==
               ARES_SUCCESS)
        {
          if ((p = try_config(line, "hosts=", '\0')) && !channel->lookups)
            /* ignore errors */
            (void)config_lookup(channel, p, "bind", NULL, "local");
        }
        fclose(fp);
      }
      else {
        error = ERRNO;
        switch(error) {
        case ENOENT:
        case ESRCH:
          break;
        default:
          DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
                         error, strerror(error)));
          DEBUGF(fprintf(stderr, "Error opening file: %s\n", "/etc/svc.conf"));
        }

        /* ignore error, default value will be chosen for `channel->lookups` */
        status = ARES_EOF;
      }
    }

    if(line)
      ares_free(line);
  }

#endif

  /* Handle errors. */
  if (status != ARES_EOF)
    {
      if (servers != NULL)
        ares_free(servers);
      if (sortlist != NULL)
        ares_free(sortlist);
      return status;
    }

  /* If we got any name server entries, fill them in. */
  if (servers)
    {
      channel->servers = servers;
      channel->nservers = nservers;
    }

  /* If we got any sortlist entries, fill them in. */
  if (sortlist)
    {
      channel->sortlist = sortlist;
      channel->nsort = nsort;
    }

  return ARES_SUCCESS;
}

static int init_by_defaults(ares_channel channel)
{
  char *hostname = NULL;
  int rc = ARES_SUCCESS;
#ifdef HAVE_GETHOSTNAME
  char *dot;
#endif

  if (channel->flags == -1)
    channel->flags = 0;
  if (channel->timeout == -1)
    channel->timeout = DEFAULT_TIMEOUT;
  if (channel->tries == -1)
    channel->tries = DEFAULT_TRIES;
  if (channel->ndots == -1)
    channel->ndots = 1;
  if (channel->rotate == -1)
    channel->rotate = 0;
  if (channel->udp_port == -1)
    channel->udp_port = htons(NAMESERVER_PORT);