/* Copyright (C) 1997-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1997.

   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 <atomic.h>

#include <ctype.h>

#include <errno.h>

#include <netdb.h>

#include <nss.h>

#include <stdint.h>

#include <string.h>

#include <arpa/inet.h>

#include <rpcsvc/nis.h>

#include <libc-lock.h>

#include "nss-nisplus.h"

__libc_lock_define_initialized (static, lock)

static nis_result *result;

static nis_name tablename_val;

static u_long tablename_len;

#define NISENTRYVAL(idx, col, res) \

        (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)

#define NISENTRYLEN(idx, col, res) \

        (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)

static int

_nss_nisplus_parse_netent (nis_result *result, struct netent *network,

			   char *buffer, size_t buflen, int *errnop)

{

  char *first_unused = buffer;

  size_t room_left = buflen;

  if (result == NULL)

    return 0;

  if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS)

      || __type_of (NIS_RES_OBJECT (result)) != NIS_ENTRY_OBJ

      || strcmp (NIS_RES_OBJECT (result)[0].EN_data.en_type,

		 "networks_tbl") != 0

      || NIS_RES_OBJECT (result)[0].EN_data.en_cols.en_cols_len < 3)

    return 0;

  if (NISENTRYLEN (0, 0, result) >= room_left)

    {

      /* The line is too long for our buffer.  */

    no_more_room:

      *errnop = ERANGE;

      return -1;

    }

  strncpy (first_unused, NISENTRYVAL (0, 0, result),

           NISENTRYLEN (0, 0, result));

  first_unused[NISENTRYLEN (0, 0, result)] = '\0';

  network->n_name = first_unused;

  size_t len = strlen (first_unused) + 1;

  room_left -= len;

  first_unused += len;

  network->n_addrtype = 0;

  network->n_net = inet_network (NISENTRYVAL (0, 2, result));

  /* XXX Rewrite at some point to allocate the array first and then

     copy the strings.  It wasteful to first concatenate the strings

     to just split them again later.  */

  char *line = first_unused;

  for (unsigned int i = 0; i < NIS_RES_NUMOBJ (result); ++i)

    {

      if (strcmp (NISENTRYVAL (i, 1, result), network->n_name) != 0)

        {

          if (NISENTRYLEN (i, 1, result) + 2 > room_left)

	    goto no_more_room;

	  *first_unused++ = ' ';

          first_unused = __stpncpy (first_unused, NISENTRYVAL (i, 1, result),

				    NISENTRYLEN (i, 1, result));

          room_left -= (NISENTRYLEN (i, 1, result) + 1);

        }

    }

  *first_unused++ = '\0';

  /* Adjust the pointer so it is aligned for

     storing pointers.  */

  size_t adjust = ((__alignof__ (char *)

		    - (first_unused - (char *) 0) % __alignof__ (char *))

		   % __alignof__ (char *));

  if (room_left < adjust + sizeof (char *))

    goto no_more_room;

  first_unused += adjust;

  room_left -= adjust;

  network->n_aliases = (char **) first_unused;

  /* For the terminating NULL pointer.  */

  room_left -= sizeof (char *);

  unsigned int i = 0;

  while (*line != '\0')

    {

      /* Skip leading blanks.  */

      while (isspace (*line))

        ++line;

      if (*line == '\0')

        break;

      if (room_left < sizeof (char *))

	goto no_more_room;

      room_left -= sizeof (char *);

      network->n_aliases[i++] = line;

      while (*line != '\0' && *line != ' ')

        ++line;

      if (*line == ' ')

	*line++ = '\0';

    }

  network->n_aliases[i] = NULL;

  return 1;

}

static enum nss_status

_nss_create_tablename (int *errnop)

{

  if (tablename_val == NULL)

    {

      const char *local_dir = nis_local_directory ();

      size_t local_dir_len = strlen (local_dir);

      static const char prefix[] = "networks.org_dir.";

      char *p = malloc (sizeof (prefix) + local_dir_len);

      if (p == NULL)

	{

	  *errnop = errno;

	  return NSS_STATUS_TRYAGAIN;

	}

      memcpy (__stpcpy (p, prefix), local_dir, local_dir_len + 1);

      tablename_len = sizeof (prefix) - 1 + local_dir_len;

      atomic_write_barrier ();

      tablename_val = p;

    }

  return NSS_STATUS_SUCCESS;

}

enum nss_status

_nss_nisplus_setnetent (int stayopen)

{

  enum nss_status status = NSS_STATUS_SUCCESS;

  __libc_lock_lock (lock);

  if (result != NULL)

    {

      nis_freeresult (result);

      result = NULL;

    }

  if (tablename_val == NULL)

    {

      int err;

      status = _nss_create_tablename (&err;;

    }

  __libc_lock_unlock (lock);

  return status;

}

enum nss_status

_nss_nisplus_endnetent (void)

{

  __libc_lock_lock (lock);

  if (result != NULL)

    {

      nis_freeresult (result);

      result = NULL;

    }

  __libc_lock_unlock (lock);

  return NSS_STATUS_SUCCESS;

}

static enum nss_status

internal_nisplus_getnetent_r (struct netent *network, char *buffer,

			       size_t buflen, int *errnop, int *herrnop)

{

  int parse_res;

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

  do

    {

      nis_result *saved_res;

      if (result == NULL)

	{

	  saved_res = NULL;

	  if (tablename_val == NULL)

	    {

	      enum nss_status status = _nss_create_tablename (errnop);

	      if (status != NSS_STATUS_SUCCESS)

		return status;

	    }

	  result = nis_first_entry (tablename_val);

	  if (result == NULL)

	    {

	      *errnop = errno;

	      return NSS_STATUS_TRYAGAIN;

	    }

	  if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)

	    {

	      int retval = niserr2nss (result->status);

	      nis_freeresult (result);

	      result = NULL;

	      if (retval == NSS_STATUS_TRYAGAIN)

		{

		  *herrnop = NETDB_INTERNAL;

		  *errnop = errno;

		  return retval;

		}

	      else

		return retval;

	    }

	}

      else

	{

	  saved_res = result;

	  result = nis_next_entry (tablename_val, &result->cookie);

	  if (result == NULL)

	    {

	      *errnop = errno;

	      return NSS_STATUS_TRYAGAIN;

	    }

	  if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)

	    {

	      int retval = niserr2nss (result->status);

	      nis_freeresult (result);

	      result = saved_res;

	      if (retval == NSS_STATUS_TRYAGAIN)

		{

		  *herrnop = NETDB_INTERNAL;

		  *errnop = errno;

		}

	      return retval;

	    }

	}

      parse_res = _nss_nisplus_parse_netent (result, network, buffer,

					     buflen, errnop);

      if (parse_res == -1)

        {

          *herrnop = NETDB_INTERNAL;

          return NSS_STATUS_TRYAGAIN;

        }

    }

  while (!parse_res);

  return NSS_STATUS_SUCCESS;

}

enum nss_status

_nss_nisplus_getnetent_r (struct netent *result, char *buffer,

			   size_t buflen, int *errnop, int *herrnop)

{

  int status;

  __libc_lock_lock (lock);

  status = internal_nisplus_getnetent_r (result, buffer, buflen, errnop,

					 herrnop);

  __libc_lock_unlock (lock);

  return status;

}

enum nss_status

_nss_nisplus_getnetbyname_r (const char *name, struct netent *network,

			      char *buffer, size_t buflen, int *errnop,

			     int *herrnop)

{

  int parse_res, retval;

  if (tablename_val == NULL)

    {

      __libc_lock_lock (lock);

      enum nss_status status = _nss_create_tablename (errnop);

      __libc_lock_unlock (lock);

      if (status != NSS_STATUS_SUCCESS)

	return status;

    }

  if (name == NULL)

    {

      *errnop = EINVAL;

      *herrnop = NETDB_INTERNAL;

      return NSS_STATUS_UNAVAIL;

    }

  nis_result *result;

  char buf[strlen (name) + 10 + tablename_len];

  int olderr = errno;

  /* Search at first in the alias list, and use the correct name

     for the next search */

  snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);

  result = nis_list (buf, FOLLOW_LINKS | FOLLOW_PATH | USE_DGRAM, NULL, NULL);

  if (result != NULL)

    {

      char *bufptr = buf;

      /* If we do not find it, try it as original name. But if the

	 database is correct, we should find it in the first case, too */

      if ((result->status != NIS_SUCCESS

	   && result->status != NIS_S_SUCCESS)

	  || __type_of (result->objects.objects_val) != NIS_ENTRY_OBJ

	  || strcmp (result->objects.objects_val[0].EN_data.en_type,

		     "networks_tbl") != 0

	  || (result->objects.objects_val[0].EN_data.en_cols.en_cols_len

	      < 3))

	snprintf (buf, sizeof (buf), "[cname=%s],%s", name, tablename_val);

      else

	{

	  /* We need to allocate a new buffer since there is no

	     guarantee the returned name has a length limit.  */

	  const char *entryval = NISENTRYVAL (0, 0, result);

	  size_t buflen = strlen (entryval) + 10 + tablename_len;

	  bufptr = alloca (buflen);

	  snprintf (bufptr, buflen, "[cname=%s],%s",

		    entryval, tablename_val);

	}

      nis_freeresult (result);

      result = nis_list (bufptr, FOLLOW_LINKS | FOLLOW_PATH | USE_DGRAM,

			 NULL, NULL);

    }

  if (result == NULL)

    {

      __set_errno (ENOMEM);

      return NSS_STATUS_TRYAGAIN;

    }

  retval = niserr2nss (result->status);

  if (__glibc_unlikely (retval != NSS_STATUS_SUCCESS))

    {

      if (retval == NSS_STATUS_TRYAGAIN)

	{

	  *errnop = errno;

	  *herrnop = NETDB_INTERNAL;

	}

      else

	__set_errno (olderr);

      nis_freeresult (result);

      return retval;

    }

  parse_res = _nss_nisplus_parse_netent (result, network, buffer, buflen,

					 errnop);

  nis_freeresult (result);

  if (parse_res > 0)

    return NSS_STATUS_SUCCESS;

  *herrnop = NETDB_INTERNAL;

  if (parse_res == -1)

    {

      *errnop = ERANGE;

      return NSS_STATUS_TRYAGAIN;

    }

  __set_errno (olderr);

  return NSS_STATUS_NOTFOUND;

}

/* XXX type is ignored, SUN's NIS+ table doesn't support it */

enum nss_status

_nss_nisplus_getnetbyaddr_r (uint32_t addr, const int type,

			     struct netent *network, char *buffer,

			     size_t buflen, int *errnop, int *herrnop)

{

  if (tablename_val == NULL)

    {

      __libc_lock_lock (lock);

      enum nss_status status = _nss_create_tablename (errnop);

      __libc_lock_unlock (lock);

      if (status != NSS_STATUS_SUCCESS)

	return status;

    }

  {

    char buf[27 + tablename_len];

    char buf2[18];

    int olderr = errno;

    struct in_addr in = { .s_addr = htonl (addr) };

    strcpy (buf2, inet_ntoa (in));

    size_t b2len = strlen (buf2);

    while (1)

      {

	snprintf (buf, sizeof (buf), "[addr=%s],%s", buf2, tablename_val);

	nis_result *result = nis_list (buf, EXPAND_NAME | USE_DGRAM,

				       NULL, NULL);

	if (result == NULL)

	  {

	    __set_errno (ENOMEM);

	    return NSS_STATUS_TRYAGAIN;

	  }

	enum nss_status retval = niserr2nss (result->status);

	if (__glibc_unlikely (retval != NSS_STATUS_SUCCESS))

	  {

	    if (b2len > 2 && buf2[b2len - 2] == '.' && buf2[b2len - 1] == '0')

	      {

		/* Try again, but with trailing dot(s)

		   removed (one by one) */

		buf2[b2len - 2] = '\0';

		b2len -= 2;

		nis_freeresult (result);

		continue;

	      }

	    if (retval == NSS_STATUS_TRYAGAIN)

	      {

		*errnop = errno;

		*herrnop = NETDB_INTERNAL;

	      }

	    else

	      __set_errno (olderr);

	    nis_freeresult (result);

	    return retval;

	  }

	int parse_res = _nss_nisplus_parse_netent (result, network, buffer,

						   buflen, errnop);

	nis_freeresult (result);

	if (parse_res > 0)

	  return NSS_STATUS_SUCCESS;

	*herrnop = NETDB_INTERNAL;

	if (parse_res == -1)

	  {

	    *errnop = ERANGE;

	    return NSS_STATUS_TRYAGAIN;

	  }

	else

	  {

	    __set_errno (olderr);

	    return NSS_STATUS_NOTFOUND;

	  }

      }

  }

}