/* Copyright (C) 1997, 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <ctype.h>
#include <errno.h>
#include <grp.h>
#include <hesiod.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <nss.h>
#include <bits/libc-lock.h>

/* Get the declaration of the parser function.  */
#define ENTNAME grent
#define STRUCTURE group
#define EXTERN_PARSER
#include <nss/nss_files/files-parse.c>

/* Locks the static variables in this file.  */
__libc_lock_define_initialized (static, lock);

static void *context = NULL;

static enum nss_status
internal_setgrent (void)
{
  if (!context)
    {
      if (hesiod_init (&context) == -1)
	return NSS_STATUS_UNAVAIL;
    }

  return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_hesiod_setgrent (void)
{
  enum nss_status status;

  __libc_lock_lock (lock);

  status = internal_setgrent ();

  __libc_lock_unlock (lock);

  return status;
}

enum nss_status
_nss_hesiod_endgrent (void)
{
  __libc_lock_lock (lock);

  if (context)
    {
      hesiod_end (context);
      context = NULL;
    }

  __libc_lock_unlock (lock);

  return NSS_STATUS_SUCCESS;
}

static enum nss_status
lookup (const char *name, const char *type, struct group *grp,
	char *buffer, size_t buflen, int *errnop)
{
  enum nss_status status;
  struct parser_data *data = (void *) buffer;
  size_t linebuflen;
  char **list;
  int parse_res;
  size_t len;

  status = internal_setgrent ();
  if (status != NSS_STATUS_SUCCESS)
    return status;

  list = hesiod_resolve (context, name, type);
  if (list == NULL)
    return errno == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;

  linebuflen = buffer + buflen - data->linebuffer;
  len = strlen (*list) + 1;
  if (linebuflen < len)
    {
      hesiod_free_list (context, list);
      *errnop = ERANGE;
      return NSS_STATUS_TRYAGAIN;
    }

  memcpy (data->linebuffer, *list, len);
  hesiod_free_list (context, list);

  parse_res = _nss_files_parse_grent (buffer, grp, data, buflen, errnop);
  if (parse_res < 1)
    return parse_res == -1 ? NSS_STATUS_TRYAGAIN : NSS_STATUS_NOTFOUND;

  return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_hesiod_getgrnam_r (const char *name, struct group *grp,
			char *buffer, size_t buflen, int *errnop)
{
  enum nss_status status;

  __libc_lock_lock (lock);

  status = lookup (name, "group", grp, buffer, buflen, errnop);

  __libc_lock_unlock (lock);

  return status;
}

enum nss_status
_nss_hesiod_getgrgid_r (gid_t gid, struct group *grp,
			char *buffer, size_t buflen, int *errnop)
{
  enum nss_status status = NSS_STATUS_UNAVAIL;
  char gidstr[21];	/* We will probably never have a gid_t with more
			   than 64 bits.  */

  snprintf (gidstr, sizeof gidstr, "%d", gid);

  __libc_lock_lock (lock);

  status = lookup (gidstr, "gid", grp, buffer, buflen, errnop);

  __libc_lock_unlock (lock);

  return status;
}

static int
internal_gid_in_list (const gid_t *list, const gid_t g, long int len)
{
  while (len > 0)
    {
      if (*list == g)
	return 1;
      --len;
      ++list;
    }
  return 0;
}

static enum nss_status
internal_gid_from_group (void *context, const char *groupname, gid_t *group)
{
  char **grp_res;
  enum nss_status status = NSS_STATUS_NOTFOUND;

  grp_res = hesiod_resolve (context, groupname, "group");
  if (grp_res != NULL && *grp_res != NULL)
    {
      char *p = *grp_res;

      while (*p != '\0' && *p != ':')
	++p;
      while (*p != '\0' && *p == ':')
	++p;
      while (*p != '\0' && *p != ':')
	++p;
      while (*p != '\0' && *p == ':')
	++p;
      if (*p == ':')
	{
	  char *endp;
	  char *q = ++p;
	  long int val;

	  q = p;
	  while (*q != '\0' && *q != ':')
	    ++q;

	  val = strtol (p, &endp, 10);
	  if (sizeof (gid_t) == sizeof (long int) || (gid_t) val == val)
	    {
	      *group = val;
	      if (endp == q && endp != p)
		status = NSS_STATUS_SUCCESS;
	    }
        }
      hesiod_free_list (context, grp_res);
    }
  return status;
}

enum nss_status
_nss_hesiod_initgroups (const char *user, gid_t group, long int *start,
                        long int *size, gid_t *groups, long int limit,
                        int *errnop)
{
  enum nss_status status = NSS_STATUS_SUCCESS;
  char **list = NULL;
  char *p;
  void *context;

  if (hesiod_init (&context) == -1)
    return NSS_STATUS_UNAVAIL;

  list = hesiod_resolve (context, user, "grplist");

  if (list == NULL)
    {
      hesiod_end (context);
      return errno == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;
    }

  if (!internal_gid_in_list (groups, group, *start) && *start < limit)
    groups[(*start)++] = group;

  p = *list;
  while (*p != '\0' && *start < limit)
    {
      char *endp;
      char *q;
      long int val;

      status = NSS_STATUS_NOTFOUND;

      q = p;
      while (*q != '\0' && *q != ':')
	++q;

      if (*q != '\0')
	*q++ = '\0';

      val = strtol (p, &endp, 10);
      if (sizeof (gid_t) == sizeof (long int) || (gid_t) val == val)
	{
	  if (*endp == '\0' && endp != p)
	    status = NSS_STATUS_SUCCESS;
	  else
	    status = internal_gid_from_group (context, p, &group);

	  if (status == NSS_STATUS_SUCCESS
	      && !internal_gid_in_list (groups, group, *start))
	    groups[(*start)++] = group;
	}

      p = q;
    }

  hesiod_free_list (context, list);
  hesiod_end (context);

  return NSS_STATUS_SUCCESS;
}