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

   This file is part of the GNU C Library.

   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 <assert.h>

#include <errno.h>

#include <libc-lock.h>

#include <stdlib.h>

#include <resolv.h>

#include "nsswitch.h"

/*******************************************************************\

|* Here we assume several symbols to be defined:		   *|

|*								   *|

|* LOOKUP_TYPE   - the return type of the function		   *|

|*								   *|

|* FUNCTION_NAME - name of the non-reentrant function		   *|

|*								   *|

|* DATABASE_NAME - name of the database the function accesses	   *|

|*		   (e.g., host, services, ...)			   *|

|*								   *|

|* ADD_PARAMS    - additional parameter, can vary in number	   *|

|*								   *|

|* ADD_VARIABLES - names of additional parameter		   *|

|*								   *|

|* BUFLEN	 - length of buffer allocated for the non	   *|

|*		   reentrant version				   *|

|*								   *|

|* Optionally the following vars can be defined:		   *|

|*								   *|

|* NEED_H_ERRNO  - an extra parameter will be passed to point to   *|

|*		   the global `h_errno' variable.		   *|

|*								   *|

\*******************************************************************/

#ifdef HANDLE_DIGITS_DOTS

# include <resolv/resolv_context.h>

#endif

/* To make the real sources a bit prettier.  */

#define REENTRANT_NAME APPEND_R (FUNCTION_NAME)

#define APPEND_R(name) APPEND_R1 (name)

#define APPEND_R1(name) name##_r

#define INTERNAL(name) INTERNAL1 (name)

#define INTERNAL1(name) __##name

/* Sometimes we need to store error codes in the `h_errno' variable.  */

#ifdef NEED_H_ERRNO

# define H_ERRNO_PARM , int *h_errnop

# define H_ERRNO_VAR , &h_errno_tmp

# define H_ERRNO_VAR_P &h_errno_tmp

#else

# define H_ERRNO_PARM

# define H_ERRNO_VAR

# define H_ERRNO_VAR_P NULL

#endif

#ifdef HAVE_AF

# define AF_VAL af

#else

# define AF_VAL AF_INET

#endif

/* Prototype for reentrant version we use here.  */

extern int INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf,

				      char *buffer, size_t buflen,

				      LOOKUP_TYPE **result H_ERRNO_PARM)

     attribute_hidden;

/* We need to protect the dynamic buffer handling.  */

__libc_lock_define_initialized (static, lock);

/* This points to the static buffer used.  */

libc_freeres_ptr (static char *buffer);

LOOKUP_TYPE *

FUNCTION_NAME (ADD_PARAMS)

{

  static size_t buffer_size;

  static LOOKUP_TYPE resbuf;

  LOOKUP_TYPE *result;

#ifdef NEED_H_ERRNO

  int h_errno_tmp = 0;

#endif

#ifdef HANDLE_DIGITS_DOTS

  /* Wrap both __nss_hostname_digits_dots and the actual lookup

     function call in the same context.  */

  struct resolv_context *res_ctx = __resolv_context_get ();

  if (res_ctx == NULL)

    {

# if NEED_H_ERRNO

      __set_h_errno (NETDB_INTERNAL);

# endif

      return NULL;

    }

#endif

  /* Get lock.  */

  __libc_lock_lock (lock);

  if (buffer == NULL)

    {

      buffer_size = BUFLEN;

      buffer = (char *) malloc (buffer_size);

    }

#ifdef HANDLE_DIGITS_DOTS

  if (buffer != NULL)

    {

      if (__nss_hostname_digits_dots_context

	  (res_ctx, name, &resbuf, &buffer, &buffer_size, 0, &result, NULL,

	   AF_VAL, H_ERRNO_VAR_P))

	goto done;

    }

#endif

  while (buffer != NULL

	 && (INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, &resbuf, buffer,

					buffer_size, &result H_ERRNO_VAR)

	     == ERANGE)

#ifdef NEED_H_ERRNO

	 && h_errno_tmp == NETDB_INTERNAL

#endif

	 )

    {

      char *new_buf;

      buffer_size *= 2;

      new_buf = (char *) realloc (buffer, buffer_size);

      if (new_buf == NULL)

	{

	  /* We are out of memory.  Free the current buffer so that the

	     process gets a chance for a normal termination.  */

	  free (buffer);

	  __set_errno (ENOMEM);

	}

      buffer = new_buf;

    }

  if (buffer == NULL)

    result = NULL;

#ifdef HANDLE_DIGITS_DOTS

done:

#endif

  /* Release lock.  */

  __libc_lock_unlock (lock);

#ifdef HANDLE_DIGITS_DOTS

  __resolv_context_put (res_ctx);

#endif

#ifdef NEED_H_ERRNO

  if (h_errno_tmp != 0)

    __set_h_errno (h_errno_tmp);

#endif

  return result;

}

nss_interface_function (FUNCTION_NAME)