/* Conversion module for UTF-32.

   Copyright (C) 1999-2018 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 <byteswap.h>

#include <dlfcn.h>

#include <gconv.h>

#include <stddef.h>

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

/* This is the Byte Order Mark character (BOM).  */

#define BOM	0x0000feffu

/* And in the other byte order.  */

#define BOM_OE	0xfffe0000u

/* Definitions used in the body of the `gconv' function.  */

#define FROM_LOOP		from_utf32_loop

#define TO_LOOP			to_utf32_loop

#define DEFINE_INIT		0

#define DEFINE_FINI		0

#define MIN_NEEDED_FROM		4

#define MIN_NEEDED_TO		4

#define ONE_DIRECTION		0

#define FROM_DIRECTION		(dir == from_utf32)

#define PREPARE_LOOP \

  enum direction dir = ((struct utf32_data *) step->__data)->dir;	      \

  enum variant var = ((struct utf32_data *) step->__data)->var;		      \

  int swap;								      \

  if (FROM_DIRECTION && var == UTF_32)					      \

    {									      \

      if (__glibc_unlikely (data->__invocation_counter == 0))		      \

	{								      \

	  /* We have to find out which byte order the file is encoded in.  */ \

	  if (inptr + 4 > inend)					      \

	    return (inptr == inend					      \

		    ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT);	      \

									      \

	  if (get32u (inptr) == BOM)					      \

	    /* Simply ignore the BOM character.  */			      \

	    *inptrp = inptr += 4;					      \

	  else if (get32u (inptr) == BOM_OE)				      \

	    {								      \

	      data->__flags |= __GCONV_SWAP;				      \

	      *inptrp = inptr += 4;					      \

	    }								      \

	}								      \

    }									      \

  else if (!FROM_DIRECTION && var == UTF_32 && !data->__internal_use	      \

	   && data->__invocation_counter == 0)				      \

    {									      \

      /* Emit the Byte Order Mark.  */					      \

      if (__glibc_unlikely (outbuf + 4 > outend))			      \

	return __GCONV_FULL_OUTPUT;					      \

									      \

      put32u (outbuf, BOM);						      \

      outbuf += 4;							      \

    }									      \

  else if (__builtin_expect (data->__invocation_counter == 0, 0)	      \

	   && ((var == UTF_32LE && BYTE_ORDER == BIG_ENDIAN)		      \

	       || (var == UTF_32BE && BYTE_ORDER == LITTLE_ENDIAN)))	      \

    data->__flags |= __GCONV_SWAP;					      \

  swap = data->__flags & __GCONV_SWAP;

#define EXTRA_LOOP_ARGS		, var, swap

/* Direction of the transformation.  */

enum direction

{

  illegal_dir,

  to_utf32,

  from_utf32

};

enum variant

{

  illegal_var,

  UTF_32,

  UTF_32LE,

  UTF_32BE

};

struct utf32_data

{

  enum direction dir;

  enum variant var;

};

extern int gconv_init (struct __gconv_step *step);

int

gconv_init (struct __gconv_step *step)

{

  /* Determine which direction.  */

  struct utf32_data *new_data;

  enum direction dir = illegal_dir;

  enum variant var = illegal_var;

  int result;

  if (__strcasecmp (step->__from_name, "UTF-32//") == 0)

    {

      dir = from_utf32;

      var = UTF_32;

    }

  else if (__strcasecmp (step->__to_name, "UTF-32//") == 0)

    {

      dir = to_utf32;

      var = UTF_32;

    }

  else if (__strcasecmp (step->__from_name, "UTF-32BE//") == 0)

    {

      dir = from_utf32;

      var = UTF_32BE;

    }

  else if (__strcasecmp (step->__to_name, "UTF-32BE//") == 0)

    {

      dir = to_utf32;

      var = UTF_32BE;

    }

  else if (__strcasecmp (step->__from_name, "UTF-32LE//") == 0)

    {

      dir = from_utf32;

      var = UTF_32LE;

    }

  else if (__strcasecmp (step->__to_name, "UTF-32LE//") == 0)

    {

      dir = to_utf32;

      var = UTF_32LE;

    }

  result = __GCONV_NOCONV;

  if (__builtin_expect (dir, to_utf32) != illegal_dir)

    {

      new_data = (struct utf32_data *) malloc (sizeof (struct utf32_data));

      result = __GCONV_NOMEM;

      if (new_data != NULL)

	{

	  new_data->dir = dir;

	  new_data->var = var;

	  step->__data = new_data;

	  if (dir == from_utf32)

	    {

	      step->__min_needed_from = MIN_NEEDED_FROM;

	      step->__max_needed_from = MIN_NEEDED_FROM;

	      step->__min_needed_to = MIN_NEEDED_TO;

	      step->__max_needed_to = MIN_NEEDED_TO;

	    }

	  else

	    {

	      step->__min_needed_from = MIN_NEEDED_TO;

	      step->__max_needed_from = MIN_NEEDED_TO;

	      step->__min_needed_to = MIN_NEEDED_FROM;

	      step->__max_needed_to = MIN_NEEDED_FROM;

	    }

	  step->__stateful = 0;

	  result = __GCONV_OK;

	}

    }

  return result;

}

extern void gconv_end (struct __gconv_step *data);

void

gconv_end (struct __gconv_step *data)

{

  free (data->__data);

}

/* Convert from the internal (UCS4-like) format to UTF-32.  */

#define MIN_NEEDED_INPUT	MIN_NEEDED_TO

#define MIN_NEEDED_OUTPUT	MIN_NEEDED_FROM

#define LOOPFCT			TO_LOOP

#define BODY \

  {									      \

    uint32_t c = get32 (inptr);						      \

									      \

    if (__glibc_unlikely (c >= 0x110000))				      \

      {									      \

	STANDARD_TO_LOOP_ERR_HANDLER (4);				      \

      }									      \

    else if (__glibc_unlikely (c >= 0xd800 && c < 0xe000))		      \

      {									      \

	/* Surrogate characters in UCS-4 input are not valid.		      \

	   We must catch this.  If we let surrogates pass through,	      \

	   attackers could make a security hole exploit by		      \

	   generating "irregular UTF-32" sequences.  */			      \

	result = __GCONV_ILLEGAL_INPUT;					      \

	if (! ignore_errors_p ())					      \

	  break;							      \

	inptr += 4;							      \

	++*irreversible;						      \

	continue;							      \

      }									      \

									      \

    if (swap)								      \

      c = bswap_32 (c);							      \

    put32 (outptr, c);							      \

									      \

    outptr += 4;							      \

    inptr += 4;								      \

  }

#define LOOP_NEED_FLAGS

#define EXTRA_LOOP_DECLS \

	, enum variant var, int swap

#include <iconv/loop.c>

/* Convert from UTF-32 to the internal (UCS4-like) format.  */

#define MIN_NEEDED_INPUT	MIN_NEEDED_FROM

#define MIN_NEEDED_OUTPUT	MIN_NEEDED_TO

#define LOOPFCT			FROM_LOOP

#define BODY \

  {									      \

    uint32_t u1 = get32 (inptr);					      \

									      \

    if (swap)								      \

      u1 = bswap_32 (u1);						      \

									      \

    if (__glibc_unlikely (u1 >= 0x110000 || (u1 >= 0xd800 && u1 < 0xe000)))   \

      {									      \

	/* This is illegal.  */						      \

	STANDARD_FROM_LOOP_ERR_HANDLER (4);				      \

      }									      \

									      \

    put32 (outptr, u1);							      \

    inptr += 4;								      \

    outptr += 4;							      \

  }

#define LOOP_NEED_FLAGS

#define EXTRA_LOOP_DECLS \

	, enum variant var, int swap

#include <iconv/loop.c>

/* Now define the toplevel functions.  */

#include <iconv/skeleton.c>