exif-mnote-data-pentax.c

Go to the documentation of this file.

/* exif-mnote-data-pentax.c
 *
 * Copyright (c) 2002, 2003 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 "config.h"
#include "exif-mnote-data-pentax.h"
 
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
 
#include <libexif/exif-byte-order.h>
#include <libexif/exif-utils.h>
 
#define CHECKOVERFLOW(offset,datasize,structsize) (( (offset) >= (datasize)) || ((structsize) > (datasize)) || ((offset) > (datasize) - (structsize) ))
 
static void
exif_mnote_data_pentax_clear (ExifMnoteDataPentax *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_pentax_free (ExifMnoteData *n)
{
        if (!n) return;
 
        exif_mnote_data_pentax_clear ((ExifMnoteDataPentax *) n);
}
 
static char *
exif_mnote_data_pentax_get_value (ExifMnoteData *d, unsigned int i, char *val, unsigned int maxlen)
{
        ExifMnoteDataPentax *n = (ExifMnoteDataPentax *) d;
 
        if (!n) return NULL;
        if (n->count <= i) return NULL;
        return mnote_pentax_entry_get_value (&n->entries[i], val, maxlen);
}
 
static void
exif_mnote_data_pentax_save (ExifMnoteData *ne,
                unsigned char **buf, unsigned int *buf_size)
{
        ExifMnoteDataPentax *n = (ExifMnoteDataPentax *) ne;
        size_t i, datao,
          base = 0,     /* internal MakerNote tag number offset */
          o2 = 4 + 2;   /* offset to first tag entry, past header */
 
        if (!n || !buf || !buf_size) return;
        datao = n->offset; /* this MakerNote style uses offsets
                              based on main IFD, not makernote IFD */
 
        /*
         * Allocate enough memory for header, the number of entries, entries,
         * and next IFD pointer
         */
        *buf_size = o2 + 2 + n->count * 12 + 4;
        switch (n->version) {
        case casioV2:
                base = MNOTE_PENTAX2_TAG_BASE;
                *buf = exif_mem_alloc (ne->mem, *buf_size);
                if (!*buf) {
                        EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataPentax", *buf_size);
                        return;
                }
                /* Write the magic header */
                strcpy ((char *)*buf, "QVC");
                exif_set_short (*buf + 4, n->order, (ExifShort) 0);
 
                break;
 
        case pentaxV3:
                base = MNOTE_PENTAX2_TAG_BASE;
                *buf = exif_mem_alloc (ne->mem, *buf_size);
                if (!*buf) {
                        EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataPentax", *buf_size);
                        return;
                }
 
                /* Write the magic header */
                strcpy ((char *)*buf, "AOC");
                exif_set_short (*buf + 4, n->order, (ExifShort) (
                        (n->order == EXIF_BYTE_ORDER_INTEL) ?
                        ('I' << 8) | 'I' :
                        ('M' << 8) | 'M'));
                break;
 
        case pentaxV2:
                base = MNOTE_PENTAX2_TAG_BASE;
                *buf = exif_mem_alloc (ne->mem, *buf_size);
                if (!*buf) {
                        EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataPentax", *buf_size);
                        return;
                }
 
                /* Write the magic header */
                strcpy ((char *)*buf, "AOC");
                exif_set_short (*buf + 4, n->order, (ExifShort) 0);
                break;
 
        case pentaxV1:
                /* It looks like this format doesn't have a magic header as
                 * such, just has a fixed number of entries equal to 0x001b */
                *buf_size -= 6;
                o2 -= 6;
                *buf = exif_mem_alloc (ne->mem, *buf_size);
                if (!*buf) {
                        EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataPentax", *buf_size);
                        return;
                }
                break;
 
        default:
                /* internal error */
                return;
        }
 
        /* Write the number of entries. */
        exif_set_short (*buf + o2, n->order, (ExifShort) n->count);
        o2 += 2;
 
        /* Save each entry */
        for (i = 0; i < n->count; i++) {
                size_t doff;    /* offset to current data portion of tag */
                size_t s;
                unsigned char *t;
                size_t o = o2 + i * 12;   /* current offset into output buffer */
                exif_set_short (*buf + o + 0, n->order,
                                (ExifShort) (n->entries[i].tag - base));
                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) {
                        size_t ts = *buf_size + s;
                        doff = *buf_size;
                        t = exif_mem_realloc (ne->mem, *buf,
                                                 sizeof (char) * ts);
                        if (!t) {
                                EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataPentax", ts);
                                return;
                        }
                        *buf = t;
                        *buf_size = ts;
                        exif_set_long (*buf + o, n->order, datao + doff);
                } else
                        doff = o;
 
                /* Write the data. */
                if (n->entries[i].data) {
                        memcpy (*buf + doff, n->entries[i].data, s);
                } else {
                        /* Most certainly damaged input file */
                        memset (*buf + doff, 0, s);
                }
        }
 
        /* Sanity check the buffer size */
        if (*buf_size < (o2 + n->count * 12 + 4)) {
                exif_log (ne->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifMnoteDataPentax",
                        "Buffer overflow");
        }
 
        /* Reset next IFD pointer */
        exif_set_long (*buf + o2 + n->count * 12, n->order, 0);
}
 
static void
exif_mnote_data_pentax_load (ExifMnoteData *en,
                const unsigned char *buf, unsigned int buf_size)
{
        ExifMnoteDataPentax *n = (ExifMnoteDataPentax *) en;
        size_t i, tcount, o, datao, base = 0;
        ExifShort c;
 
        if (!n) return;
 
        if (!buf || !buf_size) {
                exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,
                          "ExifMnoteDataPentax", "Short MakerNote");
                return;
        }
        datao = 6 + n->offset;
        if (CHECKOVERFLOW(datao, buf_size, 8)) {
                exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,
                          "ExifMnoteDataPentax", "Short MakerNote");
                return;
        }
 
        /* Detect variant of Pentax/Casio MakerNote found */
        if (!memcmp(buf + datao, "AOC", 4)) {
                if ((buf[datao + 4] == 'I') && (buf[datao + 5] == 'I')) {
                        n->version = pentaxV3;
                        n->order = EXIF_BYTE_ORDER_INTEL;
                } else if ((buf[datao + 4] == 'M') && (buf[datao + 5] == 'M')) {
                        n->version = pentaxV3;
                        n->order = EXIF_BYTE_ORDER_MOTOROLA;
                } else {
                        /* Uses Casio v2 tags */
                        n->version = pentaxV2;
                }
                exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataPentax",
                        "Parsing Pentax maker note v%d...", (int)n->version);
                datao += 4 + 2;
                base = MNOTE_PENTAX2_TAG_BASE;
        } else if (!memcmp(buf + datao, "QVC", 4)) {
                exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataPentax",
                        "Parsing Casio maker note v2...");
                n->version = casioV2;
                base = MNOTE_CASIO2_TAG_BASE;
                datao += 4 + 2;
        } else {
                /* probably assert(!memcmp(buf + datao, "\x00\x1b", 2)) */
                exif_log (en->log, EXIF_LOG_CODE_DEBUG, "ExifMnoteDataPentax",
                        "Parsing Pentax maker note v1...");
                n->version = pentaxV1;
        }
 
        /* Read the number of tags */
        c = exif_get_short (buf + datao, n->order);
        datao += 2;
 
        /* Just use an arbitrary max tag limit here to avoid needing to much memory or time. There are 102 named tags currently.
         * The format allows specifying the same range of memory as often as it can, so this multiplies quickly. */
        if (c > 200) {
                exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA, "ExifMnoteDataPentax", "Too much tags (%d) in Pentax MakerNote", c);
                return;
        }
 
 
        /* Remove any old entries */
        exif_mnote_data_pentax_clear (n);
 
        /* Reserve enough space for all the possible MakerNote tags */
        n->entries = exif_mem_alloc (en->mem, sizeof (MnotePentaxEntry) * c);
        if (!n->entries) {
                EXIF_LOG_NO_MEMORY(en->log, "ExifMnoteDataPentax", sizeof (MnotePentaxEntry) * 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(MnotePentaxEntry));
                if (CHECKOVERFLOW(o,buf_size,12)) {
                        exif_log (en->log, EXIF_LOG_CODE_CORRUPT_DATA,
                                  "ExifMnoteDataPentax", "Short MakerNote");
                        break;
                }
 
                n->entries[tcount].tag        = exif_get_short (buf + o + 0, n->order) + base;
                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, "ExifMnotePentax",
                          "Loading entry 0x%x ('%s')...", n->entries[tcount].tag,
                          mnote_pentax_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,
                                  "ExifMnoteDataPentax", "Tag size overflow detected (%u * %lu)", exif_format_get_size (n->entries[tcount].format), n->entries[tcount].components);
                        break;
                }
                /*
                 * 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;
 
                        if (CHECKOVERFLOW(dataofs, buf_size, s)) {
                                exif_log (en->log, EXIF_LOG_CODE_DEBUG,
                                                  "ExifMnoteDataPentax", "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, "ExifMnoteDataPentax", 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_pentax_count (ExifMnoteData *n)
{
        return n ? ((ExifMnoteDataPentax *) n)->count : 0;
}
 
static unsigned int
exif_mnote_data_pentax_get_id (ExifMnoteData *d, unsigned int n)
{
        ExifMnoteDataPentax *note = (ExifMnoteDataPentax *) d;
 
        if (!note) return 0;
        if (note->count <= n) return 0;
        return note->entries[n].tag;
}
 
static const char *
exif_mnote_data_pentax_get_name (ExifMnoteData *d, unsigned int n)
{
        ExifMnoteDataPentax *note = (ExifMnoteDataPentax *) d;
 
        if (!note) return NULL;
        if (note->count <= n) return NULL;
        return mnote_pentax_tag_get_name (note->entries[n].tag);
}
 
static const char *
exif_mnote_data_pentax_get_title (ExifMnoteData *d, unsigned int n)
{
        ExifMnoteDataPentax *note = (ExifMnoteDataPentax *) d;
 
        if (!note) return NULL;
        if (note->count <= n) return NULL;
        return mnote_pentax_tag_get_title (note->entries[n].tag);
}
 
static const char *
exif_mnote_data_pentax_get_description (ExifMnoteData *d, unsigned int n)
{
        ExifMnoteDataPentax *note = (ExifMnoteDataPentax *) d;
        
        if (!note) return NULL;
        if (note->count <= n) return NULL;
        return mnote_pentax_tag_get_description (note->entries[n].tag);
}
 
static void
exif_mnote_data_pentax_set_offset (ExifMnoteData *d, unsigned int o)
{
        if (d) ((ExifMnoteDataPentax *) d)->offset = o;
}
 
static void
exif_mnote_data_pentax_set_byte_order (ExifMnoteData *d, ExifByteOrder o)
{
        ExifByteOrder o_orig;
        ExifMnoteDataPentax *n = (ExifMnoteDataPentax *) 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);
        }
}
 
int
exif_mnote_data_pentax_identify (const ExifData *ed, const ExifEntry *e)
{
        (void) ed;  /* unused */
        if ((e->size >= 8) && !memcmp (e->data, "AOC", 4)) {
                if (((e->data[4] == 'I') && (e->data[5] == 'I')) ||
                    ((e->data[4] == 'M') && (e->data[5] == 'M')))
                        return pentaxV3;
                else
                        /* Uses Casio v2 tags */
                        return pentaxV2;
        }
 
        if ((e->size >= 8) && !memcmp (e->data, "QVC", 4))
                return casioV2;
 
        /* This isn't a very robust test, so make sure it's done last */
        /* Maybe we should additionally check for a make of Asahi or Pentax */
        if ((e->size >= 2) && (e->data[0] == 0x00) && (e->data[1] == 0x1b))
                return pentaxV1;
 
        return 0;
}
 
ExifMnoteData *
exif_mnote_data_pentax_new (ExifMem *mem)
{
        ExifMnoteData *d;
 
        if (!mem) return NULL;
 
        d = exif_mem_alloc (mem, sizeof (ExifMnoteDataPentax));
        if (!d) return NULL;
 
        exif_mnote_data_construct (d, mem);
 
        /* Set up function pointers */
        d->methods.free            = exif_mnote_data_pentax_free;
        d->methods.set_byte_order  = exif_mnote_data_pentax_set_byte_order;
        d->methods.set_offset      = exif_mnote_data_pentax_set_offset;
        d->methods.load            = exif_mnote_data_pentax_load;
        d->methods.save            = exif_mnote_data_pentax_save;
        d->methods.count           = exif_mnote_data_pentax_count;
        d->methods.get_id          = exif_mnote_data_pentax_get_id;
        d->methods.get_name        = exif_mnote_data_pentax_get_name;
        d->methods.get_title       = exif_mnote_data_pentax_get_title;
        d->methods.get_description = exif_mnote_data_pentax_get_description;
        d->methods.get_value       = exif_mnote_data_pentax_get_value;
 
        return d;
}