/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 * libfdt is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 *
 *  a) This library is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of the
 *     License, or (at your option) any later version.
 *
 *     This 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 General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public
 *     License along with this library; if not, write to the Free
 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *     MA 02110-1301 USA
 *
 * Alternatively,
 *
 *  b) Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *     1. Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *     2. Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "libfdt_env.h"

#include <fdt.h>
#include <libfdt.h>

#include "libfdt_internal.h"

int
fdt_check_header (const void *fdt)
{
  if (fdt_magic (fdt) == FDT_MAGIC)
    {
      /* Complete tree */
      if (fdt_version (fdt) < FDT_FIRST_SUPPORTED_VERSION)
	return -FDT_ERR_BADVERSION;
      if (fdt_last_comp_version (fdt) > FDT_LAST_SUPPORTED_VERSION)
	return -FDT_ERR_BADVERSION;
    }
  else if (fdt_magic (fdt) == FDT_SW_MAGIC)
    {
      /* Unfinished sequential-write blob */
      if (fdt_size_dt_struct (fdt) == 0)
	return -FDT_ERR_BADSTATE;
    }
  else
    {
      return -FDT_ERR_BADMAGIC;
    }

  return 0;
}

const void *
fdt_offset_ptr (const void *fdt, int offset, unsigned int len)
{
  const char *p;

  if (fdt_version (fdt) >= 0x11)
    if (((offset + len) < offset)
	|| ((offset + len) > fdt_size_dt_struct (fdt)))
      return NULL;

  p = _fdt_offset_ptr (fdt, offset);

  if (p + len < p)
    return NULL;
  return p;
}

uint32_t
fdt_next_tag (const void *fdt, int startoffset, int *nextoffset)
{
  const uint32_t *tagp, *lenp;
  uint32_t tag;
  int offset = startoffset;
  const char *p;

  *nextoffset = -FDT_ERR_TRUNCATED;
  tagp = fdt_offset_ptr (fdt, offset, FDT_TAGSIZE);
  if (!tagp)
    return FDT_END;		/* premature end */
  tag = fdt32_to_cpu (*tagp);
  offset += FDT_TAGSIZE;

  *nextoffset = -FDT_ERR_BADSTRUCTURE;
  switch (tag)
    {
    case FDT_BEGIN_NODE:
      /* skip name */
      do
	{
	  p = fdt_offset_ptr (fdt, offset++, 1);
	}
      while (p && (*p != '\0'));
      if (!p)
	return FDT_END;		/* premature end */
      break;

    case FDT_PROP:
      lenp = fdt_offset_ptr (fdt, offset, sizeof (*lenp));
      if (!lenp)
	return FDT_END;		/* premature end */
      /* skip-name offset, length and value */
      offset += sizeof (struct fdt_property) - FDT_TAGSIZE
	+ fdt32_to_cpu (*lenp);
      break;

    case FDT_END:
    case FDT_END_NODE:
    case FDT_NOP:
      break;

    default:
      return FDT_END;
    }

  if (!fdt_offset_ptr (fdt, startoffset, offset - startoffset))
    return FDT_END;		/* premature end */

  *nextoffset = FDT_TAGALIGN (offset);
  return tag;
}

int
_fdt_check_node_offset (const void *fdt, int offset)
{
  if ((offset < 0) || (offset % FDT_TAGSIZE)
      || (fdt_next_tag (fdt, offset, &offset) != FDT_BEGIN_NODE))
    return -FDT_ERR_BADOFFSET;

  return offset;
}

int
_fdt_check_prop_offset (const void *fdt, int offset)
{
  if ((offset < 0) || (offset % FDT_TAGSIZE)
      || (fdt_next_tag (fdt, offset, &offset) != FDT_PROP))
    return -FDT_ERR_BADOFFSET;

  return offset;
}

int
fdt_next_node (const void *fdt, int offset, int *depth)
{
  int nextoffset = 0;
  uint32_t tag;

  if (offset >= 0)
    if ((nextoffset = _fdt_check_node_offset (fdt, offset)) < 0)
      return nextoffset;

  do
    {
      offset = nextoffset;
      tag = fdt_next_tag (fdt, offset, &nextoffset);

      switch (tag)
	{
	case FDT_PROP:
	case FDT_NOP:
	  break;

	case FDT_BEGIN_NODE:
	  if (depth)
	    (*depth)++;
	  break;

	case FDT_END_NODE:
	  if (depth && ((--(*depth)) < 0))
	    return nextoffset;
	  break;

	case FDT_END:
	  if ((nextoffset >= 0)
	      || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
	    return -FDT_ERR_NOTFOUND;
	  else
	    return nextoffset;
	}
    }
  while (tag != FDT_BEGIN_NODE);

  return offset;
}

const char *
_fdt_find_string (const char *strtab, int tabsize, const char *s)
{
  int len = strlen (s) + 1;
  const char *last = strtab + tabsize - len;
  const char *p;

  for (p = strtab; p <= last; p++)
    if (memcmp (p, s, len) == 0)
      return p;
  return NULL;
}

int
fdt_move (const void *fdt, void *buf, int bufsize)
{
  FDT_CHECK_HEADER (fdt);

  if (fdt_totalsize (fdt) > bufsize)
    return -FDT_ERR_NOSPACE;

  memmove (buf, fdt, fdt_totalsize (fdt));
  return 0;
}