/* Copyright (C) 2011-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <alloca.h>

#include <errno.h>

#include <stdlib.h>

#include <string.h>

#include <not-cancel.h>

#include "nscd-client.h"

#include "nscd_proto.h"

int __nss_not_use_nscd_netgroup;

libc_locked_map_ptr (static, map_handle);

/* Note that we only free the structure if necessary.  The memory

   mapping is not removed since it is not visible to the malloc

   handling.  */

libc_freeres_fn (pw_map_free)

{

  if (map_handle.mapped != NO_MAPPING)

    {

      void *p = map_handle.mapped;

      map_handle.mapped = NO_MAPPING;

      free (p);

    }

}

int

__nscd_setnetgrent (const char *group, struct __netgrent *datap)

{

  int gc_cycle;

  int nretries = 0;

  size_t group_len = strlen (group) + 1;

  /* If the mapping is available, try to search there instead of

     communicating with the nscd.  */

  struct mapped_database *mapped;

  mapped = __nscd_get_map_ref (GETFDNETGR, "netgroup", &map_handle, &gc_cycle);

 retry:;

  char *respdata = NULL;

  int retval = -1;

  netgroup_response_header netgroup_resp;

  if (mapped != NO_MAPPING)

    {

      struct datahead *found = __nscd_cache_search (GETNETGRENT, group,

						    group_len, mapped,

						    sizeof netgroup_resp);

      if (found != NULL)

	{

	  respdata = (char *) (&found->data[0].netgroupdata + 1);

	  netgroup_resp = found->data[0].netgroupdata;

	  /* Now check if we can trust pw_resp fields.  If GC is

	     in progress, it can contain anything.  */

	  if (mapped->head->gc_cycle != gc_cycle)

	    {

	      retval = -2;

	      goto out;

	    }

	}

    }

  int sock = -1;

  if (respdata == NULL)

    {

      sock = __nscd_open_socket (group, group_len, GETNETGRENT,

				 &netgroup_resp, sizeof (netgroup_resp));

      if (sock == -1)

	{

	  /* nscd not running or wrong version.  */

	  __nss_not_use_nscd_netgroup = 1;

	  goto out;

	}

    }

  if (netgroup_resp.found == 1)

    {

      size_t datalen = netgroup_resp.result_len;

      /* If we do not have to read the data here it comes from the

	 mapped data and does not have to be freed.  */

      if (respdata == NULL)

	{

	  /* The data will come via the socket.  */

	  respdata = malloc (datalen);

	  if (respdata == NULL)

	    goto out_close;

	  if ((size_t) __readall (sock, respdata, datalen) != datalen)

	    {

	      free (respdata);

	      goto out_close;

	    }

	}

      datap->data = respdata;

      datap->data_size = datalen;

      datap->cursor = respdata;

      datap->first = 1;

      datap->nip = (service_user *) -1l;

      datap->known_groups = NULL;

      datap->needed_groups = NULL;

      retval = 1;

    }

  else

    {

      if (__glibc_unlikely (netgroup_resp.found == -1))

	{

	  /* The daemon does not cache this database.  */

	  __nss_not_use_nscd_netgroup = 1;

	  goto out_close;

	}

      /* Set errno to 0 to indicate no error, just no found record.  */

      __set_errno (0);

      /* Even though we have not found anything, the result is zero.  */

      retval = 0;

    }

 out_close:

  if (sock != -1)

    __close_nocancel_nostatus (sock);

 out:

  if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)

    {

      /* When we come here this means there has been a GC cycle while we

	 were looking for the data.  This means the data might have been

	 inconsistent.  Retry if possible.  */

      if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)

	{

	  /* nscd is just running gc now.  Disable using the mapping.  */

	  if (atomic_decrement_val (&mapped->counter) == 0)

	    __nscd_unmap (mapped);

	  mapped = NO_MAPPING;

	}

      if (retval != -1)

	goto retry;

    }

  return retval;

}

int

__nscd_innetgr (const char *netgroup, const char *host, const char *user,

		const char *domain)

{

  size_t key_len = (strlen (netgroup) + strlen (host ?: "")

		    + strlen (user ?: "") + strlen (domain ?: "") + 7);

  char *key;

  bool use_alloca = __libc_use_alloca (key_len);

  if (use_alloca)

    key = alloca (key_len);

  else

    {

      key = malloc (key_len);

      if (key == NULL)

	return -1;

    }

  char *wp = stpcpy (key, netgroup) + 1;

  if (host != NULL)

    {

      *wp++ = '\1';

      wp = stpcpy (wp, host) + 1;

    }

  else

    *wp++ = '\0';

  if (user != NULL)

    {

      *wp++ = '\1';

      wp = stpcpy (wp, user) + 1;

    }

  else

    *wp++ = '\0';

  if (domain != NULL)

    {

      *wp++ = '\1';

      wp = stpcpy (wp, domain) + 1;

    }

  else

    *wp++ = '\0';

  key_len = wp - key;

  /* If the mapping is available, try to search there instead of

     communicating with the nscd.  */

  int gc_cycle;

  int nretries = 0;

  struct mapped_database *mapped;

  mapped = __nscd_get_map_ref (GETFDNETGR, "netgroup", &map_handle, &gc_cycle);

 retry:;

  int retval = -1;

  innetgroup_response_header innetgroup_resp;

  int sock = -1;

  if (mapped != NO_MAPPING)

    {

      struct datahead *found = __nscd_cache_search (INNETGR, key,

						    key_len, mapped,

						    sizeof innetgroup_resp);

      if (found != NULL)

	{

	  innetgroup_resp = found->data[0].innetgroupdata;

	  /* Now check if we can trust pw_resp fields.  If GC is

	     in progress, it can contain anything.  */

	  if (mapped->head->gc_cycle != gc_cycle)

	    {

	      retval = -2;

	      goto out;

	    }

	  goto found_entry;

	}

    }

  sock = __nscd_open_socket (key, key_len, INNETGR,

			     &innetgroup_resp, sizeof (innetgroup_resp));

  if (sock == -1)

    {

      /* nscd not running or wrong version.  */

      __nss_not_use_nscd_netgroup = 1;

      goto out;

    }

 found_entry:

  if (innetgroup_resp.found == 1)

    retval = innetgroup_resp.result;

  else

    {

      if (__glibc_unlikely (innetgroup_resp.found == -1))

	{

	  /* The daemon does not cache this database.  */

	  __nss_not_use_nscd_netgroup = 1;

	  goto out_close;

	}

      /* Set errno to 0 to indicate no error, just no found record.  */

      __set_errno (0);

      /* Even though we have not found anything, the result is zero.  */

      retval = 0;

    }

 out_close:

  if (sock != -1)

    __close_nocancel_nostatus (sock);

 out:

  if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)

    {

      /* When we come here this means there has been a GC cycle while we

	 were looking for the data.  This means the data might have been

	 inconsistent.  Retry if possible.  */

      if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)

	{

	  /* nscd is just running gc now.  Disable using the mapping.  */

	  if (atomic_decrement_val (&mapped->counter) == 0)

	    __nscd_unmap (mapped);

	  mapped = NO_MAPPING;

	}

      if (retval != -1)

	goto retry;

    }

  if (! use_alloca)

    free (key);

  return retval;

}