path: root/nscd/netgroupcache.c

/* Cache handling for netgroup lookup.
   Copyright (C) 2011-2013 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.

   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; version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.  */

#include <alloca.h>
#include <assert.h>
#include <errno.h>
#include <libintl.h>
#include <stdbool.h>
#include <unistd.h>
#include <sys/mman.h>

#include "../inet/netgroup.h"
#include "nscd.h"
#include "dbg_log.h"

#include <kernel-features.h>


/* This is the standard reply in case the service is disabled.  */
static const netgroup_response_header disabled =
{
  .version = NSCD_VERSION,
  .found = -1,
  .nresults = 0,
  .result_len = 0
};

/* This is the struct describing how to write this record.  */
const struct iovec netgroup_iov_disabled =
{
  .iov_base = (void *) &disabled,
  .iov_len = sizeof (disabled)
};


/* This is the standard reply in case we haven't found the dataset.  */
static const netgroup_response_header notfound =
{
  .version = NSCD_VERSION,
  .found = 0,
  .nresults = 0,
  .result_len = 0
};


struct dataset
{
  struct datahead head;
  netgroup_response_header resp;
  char strdata[0];
};


static time_t
addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
		 const char *key, uid_t uid, struct hashentry *he,
		 struct datahead *dh, struct dataset **resultp)
{
  if (__builtin_expect (debug_level > 0, 0))
    {
      if (he == NULL)
	dbg_log (_("Haven't found \"%s\" in netgroup cache!"), key);
      else
	dbg_log (_("Reloading \"%s\" in netgroup cache!"), key);
    }

  static service_user *netgroup_database;
  time_t timeout;
  struct dataset *dataset;
  bool cacheable = false;
  ssize_t total;

  char *key_copy = NULL;
  struct __netgrent data;
  size_t buflen = MAX (1024, sizeof (*dataset) + req->key_len);
  size_t buffilled = sizeof (*dataset);
  char *buffer = NULL;
  size_t nentries = 0;
  bool use_malloc = false;
  size_t group_len = strlen (key) + 1;
  union
  {
    struct name_list elem;
    char mem[sizeof (struct name_list) + group_len];
  } first_needed;

  if (netgroup_database == NULL
      && __nss_database_lookup ("netgroup", NULL