/* Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Thorsten Kukuk <kukuk@suse.de>, 1996.

   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 <ctype.h>

#include <errno.h>

#include <grp.h>

#include <nss.h>

#include <string.h>

#include <libc-lock.h>

#include <rpcsvc/yp.h>

#include <rpcsvc/ypclnt.h>

#include "nss-nis.h"

#include <libnsl.h>

/* Get the declaration of the parser function.  */

#define ENTNAME grent

#define STRUCTURE group

#define EXTERN_PARSER

#include <nss/nss_files/files-parse.c>

/* Protect global state against multiple changers */

__libc_lock_define_initialized (static, lock)

static bool_t new_start = 1;

static char *oldkey;

static int oldkeylen;

static intern_t intern;

static void

internal_nis_endgrent (void)

{

  new_start = 1;

  if (oldkey != NULL)

    {

      free (oldkey);

      oldkey = NULL;

      oldkeylen = 0;

    }

  struct response_t *curr = intern.start;

  while (curr != NULL)

    {

      struct response_t *last = curr;

      curr = curr->next;

      free (last);

    }

  intern.next = intern.start = NULL;

}

enum nss_status

_nss_nis_endgrent (void)

{

  __libc_lock_lock (lock);

  internal_nis_endgrent ();

  __libc_lock_unlock (lock);

  return NSS_STATUS_SUCCESS;

}

enum nss_status

internal_nis_setgrent (void)

{

  /* We have to read all the data now.  */

  char *domain;

  if (__glibc_unlikely (yp_get_default_domain (&domain)))

    return NSS_STATUS_UNAVAIL;

  struct ypall_callback ypcb;

  ypcb.foreach = _nis_saveit;

  ypcb.data = (char *) &intern;

  enum nss_status status = yperr2nss (yp_all (domain, "group.byname", &ypcb));

  /* Mark the last buffer as full.  */

  if (intern.next != NULL)

    intern.next->size = intern.offset;

  intern.next = intern.start;

  intern.offset = 0;

  return status;

}

enum nss_status

_nss_nis_setgrent (int stayopen)

{

  enum nss_status result = NSS_STATUS_SUCCESS;

  __libc_lock_lock (lock);

  internal_nis_endgrent ();

  if (_nsl_default_nss () & NSS_FLAG_SETENT_BATCH_READ)

    result = internal_nis_setgrent ();

  __libc_lock_unlock (lock);

  return result;

}

static enum nss_status

internal_nis_getgrent_r (struct group *grp, char *buffer, size_t buflen,

			 int *errnop)

{

  /* If we read the entire database at setpwent time we just iterate

     over the data we have in memory.  */

  bool batch_read = intern.start != NULL;

  char *domain = NULL;

  if (!batch_read && __builtin_expect (yp_get_default_domain (&domain), 0))

    return NSS_STATUS_UNAVAIL;

  /* Get the next entry until we found a correct one. */

  int parse_res;

  do

    {

      char *result;

      char *outkey;

      int len;

      int keylen;

      if (batch_read)

	{

	  struct response_t *bucket;

	handle_batch_read:

	  bucket = intern.next;

	  if (__glibc_unlikely (intern.offset >= bucket->size))

	    {

	      if (bucket->next == NULL)

		return NSS_STATUS_NOTFOUND;

	      /* We look at all the content in the current bucket.  Go on

		 to the next.  */

	      bucket = intern.next = bucket->next;

	      intern.offset = 0;

	    }

	  for (result = &bucket->mem[intern.offset]; isspace (*result);

	       ++result)

	    ++intern.offset;

	  len = strlen (result);

	}

      else

	{

	  int yperr;

	  if (new_start)

	    {

	      /* Maybe we should read the database in one piece.  */

	      if ((_nsl_default_nss () & NSS_FLAG_SETENT_BATCH_READ)

		  && internal_nis_setgrent () == NSS_STATUS_SUCCESS

		  && intern.start != NULL)

		{

		  batch_read = true;

		  goto handle_batch_read;

		}

	      yperr = yp_first (domain, "group.byname", &outkey, &keylen,

				&result, &len;;

	    }

	  else

	    yperr = yp_next (domain, "group.byname", oldkey, oldkeylen,

			     &outkey, &keylen, &result, &len;;

	  if (__glibc_unlikely (yperr != YPERR_SUCCESS))

	    {

	      enum nss_status retval = yperr2nss (yperr);

	      if (retval == NSS_STATUS_TRYAGAIN)

		*errnop = errno;

	      return retval;

	    }

	}

      if (__glibc_unlikely ((size_t) (len + 1) > buflen))

	{

	  if (!batch_read)

	    free (result);

	  *errnop = ERANGE;

	  return NSS_STATUS_TRYAGAIN;

	}

      char *p = strncpy (buffer, result, len);

      buffer[len] = '\0';

      while (isspace (*p))

	++p;

      if (!batch_read)

	free (result);

      parse_res = _nss_files_parse_grent (p, grp, (void *) buffer, buflen,

					  errnop);

      if (__glibc_unlikely (parse_res == -1))

	{

	  if (!batch_read)

	    free (outkey);

	  *errnop = ERANGE;

	  return NSS_STATUS_TRYAGAIN;

	}

      if (batch_read)

	intern.offset += len + 1;

      else

	{

	  free (oldkey);

	  oldkey = outkey;

	  oldkeylen = keylen;

	  new_start = 0;

	}

    }

  while (parse_res < 1);

  return NSS_STATUS_SUCCESS;

}

enum nss_status

_nss_nis_getgrent_r (struct group *result, char *buffer, size_t buflen,

		     int *errnop)

{

  int status;

  __libc_lock_lock (lock);

  status = internal_nis_getgrent_r (result, buffer, buflen, errnop);

  __libc_lock_unlock (lock);

  return status;

}

enum nss_status

_nss_nis_getgrnam_r (const char *name, struct group *grp,

		     char *buffer, size_t buflen, int *errnop)

{

  if (name == NULL)

    {

      *errnop = EINVAL;

      return NSS_STATUS_UNAVAIL;

    }

  char *domain;

  if (__glibc_unlikely (yp_get_default_domain (&domain)))

    return NSS_STATUS_UNAVAIL;

  char *result;

  int len;

  int yperr = yp_match (domain, "group.byname", name, strlen (name), &result,

			&len;;

  if (__glibc_unlikely (yperr != YPERR_SUCCESS))

    {

      enum nss_status retval = yperr2nss (yperr);

      if (retval == NSS_STATUS_TRYAGAIN)

	*errnop = errno;

      return retval;

    }

  if (__glibc_unlikely ((size_t) (len + 1) > buflen))

    {

      free (result);

      *errnop = ERANGE;

      return NSS_STATUS_TRYAGAIN;

    }

  char *p = strncpy (buffer, result, len);

  buffer[len] = '\0';

  while (isspace (*p))

    ++p;

  free (result);

  int parse_res = _nss_files_parse_grent (p, grp, (void *) buffer, buflen,

					  errnop);

  if (__builtin_expect  (parse_res < 1, 0))

    {

      if (parse_res == -1)

	return NSS_STATUS_TRYAGAIN;

      else

	return NSS_STATUS_NOTFOUND;

    }

  return NSS_STATUS_SUCCESS;

}

enum nss_status

_nss_nis_getgrgid_r (gid_t gid, struct group *grp,

		     char *buffer, size_t buflen, int *errnop)

{

  char *domain;

  if (__glibc_unlikely (yp_get_default_domain (&domain)))

    return NSS_STATUS_UNAVAIL;

  char buf[32];

  int nlen = sprintf (buf, "%lu", (unsigned long int) gid);

  char *result;

  int len;

  int yperr = yp_match (domain, "group.bygid", buf, nlen, &result, &len;;

  if (__glibc_unlikely (yperr != YPERR_SUCCESS))

    {

      enum nss_status retval = yperr2nss (yperr);

      if (retval == NSS_STATUS_TRYAGAIN)

	*errnop = errno;

      return retval;

    }

  if (__glibc_unlikely ((size_t) (len + 1) > buflen))

    {

      free (result);

      *errnop = ERANGE;

      return NSS_STATUS_TRYAGAIN;

    }

  char *p = strncpy (buffer, result, len);

  buffer[len] = '\0';

  while (isspace (*p))

    ++p;

  free (result);

  int parse_res = _nss_files_parse_grent (p, grp, (void *) buffer, buflen,

					  errnop);

  if (__glibc_unlikely (parse_res < 1))

    {

      if (parse_res == -1)

	return NSS_STATUS_TRYAGAIN;

      else

	return NSS_STATUS_NOTFOUND;

    }

  return NSS_STATUS_SUCCESS;

}