/* exif-mnote-data-fuji.c

 *

 * Copyright (c) 2002 Lutz Mueller <lutz@users.sourceforge.net>

 *

 * This 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 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

 * Lesser General Public License for more details. 

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA  02110-1301  USA.

 *

 * SPDX-License-Identifier: LGPL-2.0-or-later

 */

#include <stdlib.h>

#include <string.h>

#include <config.h>

#include <libexif/exif-byte-order.h>

#include <libexif/exif-utils.h>

#include "exif-mnote-data-fuji.h"

#define CHECKOVERFLOW(offset,datasize,structsize) (( (offset) >= (datasize)) || ((structsize) > (datasize)) || ((offset) > (datasize) - (structsize) ))

struct _MNoteFujiDataPrivate {

  ExifByteOrder order;

};

static void

exif_mnote_data_fuji_clear (ExifMnoteDataFuji *n)

{

  ExifMnoteData *d = (ExifMnoteData *) n;

  unsigned int i;

  if (!n) return;

  if (n->entries) {

    for (i = 0; i < n->count; i++)

      if (n->entries[i].data) {

        exif_mem_free (d->mem, n->entries[i].data);

        n->entries[i].data = NULL;

      }

    exif_mem_free (d->mem, n->entries);

    n->entries = NULL;

    n->count = 0;

  }

}

static void

exif_mnote_data_fuji_free (ExifMnoteData *n)

{

  if (!n) return;

  exif_mnote_data_fuji_clear ((ExifMnoteDataFuji *) n);

}

static char *

exif_mnote_data_fuji_get_value (ExifMnoteData *d, unsigned int i, char *val, unsigned int maxlen)

{

  ExifMnoteDataFuji *n = (ExifMnoteDataFuji *) d;

  if (!d || !val) return NULL;

  if (i > n->count -1) return NULL;

/*

  exif_log (d->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataFuji",

      "Querying value for tag '%s'...",

      mnote_fuji_tag_get_name (n->entries[i].tag));

*/

  return mnote_fuji_entry_get_value (&n->entries[i], val, maxlen);

}

static void

exif_mnote_data_fuji_save (ExifMnoteData *ne, unsigned char **buf,

         unsigned int *buf_size)

{

  ExifMnoteDataFuji *n = (ExifMnoteDataFuji *) ne;

  size_t i, o, s, doff;

  unsigned char *t;

  size_t ts;

  if (!n || !buf || !buf_size) return;

  /*

   * Allocate enough memory for all entries and the number

   * of entries.

   */

  *buf_size = 8 + 4 + 2 + n->count * 12 + 4;

  *buf = exif_mem_alloc (ne->mem, *buf_size);

  if (!*buf) {

    *buf_size = 0;

    return;

  }

  /*

   * Header: "FUJIFILM" and 4 bytes offset to the first entry.

   * As the first entry will start right thereafter, the offset is 12.

   */

  memcpy (*buf, "FUJIFILM", 8);

  exif_set_long (*buf + 8, n->order, 12);

  /* Save the number of entries */

  exif_set_short (*buf + 8 + 4, n->order, (ExifShort) n->count);

  /* Save each entry */

  for (i = 0; i < n->count; i++) {

    o = 8 + 4 + 2 + i * 12;

    exif_set_short (*buf + o + 0, n->order, (ExifShort) n->entries[i].tag);

    exif_set_short (*buf + o + 2, n->order, (ExifShort) n->entries[i].format);

    exif_set_long  (*buf + o + 4, n->order, n->entries[i].components);

    o += 8;

    s = exif_format_get_size (n->entries[i].format) *

            n->entries[i].components;

    if (s > 65536) {

      /* Corrupt data: EXIF data size is limited to the

       * maximum size of a JPEG segment (64 kb).

       */

      continue;

    }

    if (s > 4) {

      ts = *buf_size + s;

      /* Ensure even offsets. Set padding bytes to 0. */

      if (s & 1) ts += 1;

      t = exif_mem_realloc (ne->mem, *buf, ts);

      if (!t) {

        return;

      }

      *buf = t;

      *buf_size = ts;

      doff = *buf_size - s;

      if (s & 1) { doff--; *(*buf + *buf_size - 1) = '\0'; }

      exif_set_long (*buf + o, n->order, doff);

    } else

      doff = o;

    /*

     * Write the data. Fill unneeded bytes with 0. Do not

     * crash if data is NULL.

     */

    if (!n->entries[i].data) memset (*buf + doff, 0, s);

    else memcpy (*buf + doff, n->entries[i].data, s);

  }

}

static void

exif_mnote_data_fuji_load (ExifMnoteData *en,

  const unsigned char *buf, unsigned int buf_size)

{

  ExifMnoteDataFuji *n = (ExifMnoteDataFuji*) en;

  ExifLong c;

  size_t i, tcount, o, datao;

  if (!n) return;

  if (!buf || !buf_size) {

    exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,

        "ExifMnoteDataFuji", "Short MakerNote");

    return;

  }

  if (CHECKOVERFLOW(n->offset, buf_size, 6+8+4)) {

    exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,

        "ExifMnoteDataFuji", "Short MakerNote");

    return;

  }

  datao = 6 + n->offset;

  n->order = EXIF_BYTE_ORDER_INTEL;

  datao += exif_get_long (buf + datao + 8, EXIF_BYTE_ORDER_INTEL);

  if (CHECKOVERFLOW(datao, buf_size, 2)) {

    exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,

        "ExifMnoteDataFuji", "Short MakerNote");

    return;

  }

  /* Read the number of tags */

  c = exif_get_short (buf + datao, EXIF_BYTE_ORDER_INTEL);

  datao += 2;

  /* Just use an arbitrary max tag limit here to avoid needing to much memory or time. There are 50 named tags currently.

   * Fuji XT2 had 56 entries or so, GFX500 has 68. 150 seems a safe upper bound currently.

   * The format allows specifying the same range of memory as often as it can, so this multiplies quickly. */

  if (c > 150) {

    exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifMnoteDataFuji", "Too much tags (%d) in Fuji MakerNote", c);

    return;

  }

  /* Remove any old entries */

  exif_mnote_data_fuji_clear (n);

  /* Reserve enough space for all the possible MakerNote tags */

  n->entries = exif_mem_alloc (en->mem, sizeof (MnoteFujiEntry) * c);

  if (!n->entries) {

    EXIF_LOG_NO_MEMORY(en->log, "ExifMnoteDataFuji", sizeof (MnoteFujiEntry) * c);

    return;

  }

  /* Parse all c entries, storing ones that are successfully parsed */

  tcount = 0;

  for (i = c, o = datao; i; --i, o += 12) {

    size_t s;

    memset(&n->entries[tcount], 0, sizeof(MnoteFujiEntry));

    if (CHECKOVERFLOW(o, buf_size, 12)) {

      exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,

          "ExifMnoteDataFuji", "Short MakerNote");

      break;

    }

    n->entries[tcount].tag        = exif_get_short (buf + o, n->order);

    n->entries[tcount].format     = exif_get_short (buf + o + 2, n->order);

    n->entries[tcount].components = exif_get_long (buf + o + 4, n->order);

    n->entries[tcount].order      = n->order;

    exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataFuji",

        "Loading entry 0x%x ('%s')...", n->entries[tcount].tag,

        mnote_fuji_tag_get_name (n->entries[tcount].tag));

    /* Check if we overflow the multiplication. Use buf_size as the max size for integer overflow detection,

     * we will check the buffer sizes closer later. */

    if (  exif_format_get_size (n->entries[tcount].format) &&

      buf_size / exif_format_get_size (n->entries[tcount].format) < n->entries[tcount].components

    ) {

      exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,

            "ExifMnoteDataFuji", "Tag size overflow detected (%u * %lu)", exif_format_get_size (n->entries[tcount].format), n->entries[tcount].components);

      continue;

    }

    /*

     * Size? If bigger than 4 bytes, the actual data is not

     * in the entry but somewhere else (offset).

     */

    s = exif_format_get_size (n->entries[tcount].format) * n->entries[tcount].components;

    n->entries[tcount].size = s;

    if (s) {

      size_t dataofs = o + 8;

      if (s > 4)

        /* The data in this case is merely a pointer */

        dataofs = exif_get_long (buf + dataofs, n->order) + 6 + n->offset;

      if (CHECKOVERFLOW(dataofs, buf_size, s)) {

        exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,

              "ExifMnoteDataFuji", "Tag data past end of "

            "buffer (%u >= %u)", (unsigned)(dataofs + s), buf_size);

        continue;

      }

      n->entries[tcount].data = exif_mem_alloc (en->mem, s);

      if (!n->entries[tcount].data) {

        EXIF_LOG_NO_MEMORY(en->log, "ExifMnoteDataFuji", s);

        continue;

      }

      memcpy (n->entries[tcount].data, buf + dataofs, s);

    }

    /* Tag was successfully parsed */

    ++tcount;

  }

  /* Store the count of successfully parsed tags */

  n->count = tcount;

}

static unsigned int

exif_mnote_data_fuji_count (ExifMnoteData *n)

{

  return n ? ((ExifMnoteDataFuji *) n)->count : 0;

}

static unsigned int

exif_mnote_data_fuji_get_id (ExifMnoteData *d, unsigned int n)

{

  ExifMnoteDataFuji *note = (ExifMnoteDataFuji *) d;

  if (!note) return 0;

  if (note->count <= n) return 0;

  return note->entries[n].tag;

}

static const char *

exif_mnote_data_fuji_get_name (ExifMnoteData *d, unsigned int i)

{

  ExifMnoteDataFuji *n = (ExifMnoteDataFuji *) d;

  if (!n) return NULL;

  if (i >= n->count) return NULL;

  return mnote_fuji_tag_get_name (n->entries[i].tag);

}

static const char *

exif_mnote_data_fuji_get_title (ExifMnoteData *d, unsigned int i)

{

  ExifMnoteDataFuji *n = (ExifMnoteDataFuji *) d;

  if (!n) return NULL;

  if (i >= n->count) return NULL;

        return mnote_fuji_tag_get_title (n->entries[i].tag);

}

static const char *

exif_mnote_data_fuji_get_description (ExifMnoteData *d, unsigned int i)

{

  ExifMnoteDataFuji *n = (ExifMnoteDataFuji *) d;

  if (!n) return NULL;

  if (i >= n->count) return NULL;

        return mnote_fuji_tag_get_description (n->entries[i].tag);

}

static void

exif_mnote_data_fuji_set_byte_order (ExifMnoteData *d, ExifByteOrder o)

{

  ExifByteOrder o_orig;

  ExifMnoteDataFuji *n = (ExifMnoteDataFuji *) d;

  unsigned int i;

  if (!n) return;

  o_orig = n->order;

  n->order = o;

  for (i = 0; i < n->count; i++) {

    if (n->entries[i].components && (n->entries[i].size/n->entries[i].components < exif_format_get_size (n->entries[i].format)))

      continue;

    n->entries[i].order = o;

    exif_array_set_byte_order (n->entries[i].format, n->entries[i].data,

        n->entries[i].components, o_orig, o);

  }

}

static void

exif_mnote_data_fuji_set_offset (ExifMnoteData *n, unsigned int o)

{

  if (n) ((ExifMnoteDataFuji *) n)->offset = o;

}

int

exif_mnote_data_fuji_identify (const ExifData *ed, const ExifEntry *e)

{

  (void) ed;  /* unused */

  return ((e->size >= 12) && !memcmp (e->data, "FUJIFILM", 8));

}

ExifMnoteData *

exif_mnote_data_fuji_new (ExifMem *mem)

{

  ExifMnoteData *d;

  if (!mem) return NULL;

  d = exif_mem_alloc (mem, sizeof (ExifMnoteDataFuji));

  if (!d) return NULL;

  exif_mnote_data_construct (d, mem);

  /* Set up function pointers */

  d->methods.free            = exif_mnote_data_fuji_free;

  d->methods.set_byte_order  = exif_mnote_data_fuji_set_byte_order;

  d->methods.set_offset      = exif_mnote_data_fuji_set_offset;

  d->methods.load            = exif_mnote_data_fuji_load;

  d->methods.save            = exif_mnote_data_fuji_save;

  d->methods.count           = exif_mnote_data_fuji_count;

  d->methods.get_id          = exif_mnote_data_fuji_get_id;

  d->methods.get_name        = exif_mnote_data_fuji_get_name;

  d->methods.get_title       = exif_mnote_data_fuji_get_title;

  d->methods.get_description = exif_mnote_data_fuji_get_description;

  d->methods.get_value       = exif_mnote_data_fuji_get_value;

  return d;

}