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/*
* Copyright (C) 2014 Olivier Gayot <duskcoder@gmail.com>
*
* This program 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 program 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 program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sysexits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "bmp.h"
static int stegmp_parse_windows_bitmap_info_header(const unsigned char *addr,
size_t size, struct bitmap *bmpp)
{
struct bitmap_info_header info_header;
if (size < sizeof(typeof(info_header))) {
bmp_errno = BMP_EINVALSIZ;
return -1;
}
info_header = *((typeof(info_header) *)addr);
switch (info_header.bpp) {
case 8:
case 16:
case 24:
case 32:
bmpp->bpp = info_header.bpp;
break;
default:
bmp_errno = BMP_EINVALBPP;
return -1;
}
/* TODO check the compression type */
bmpp->width = info_header.bmp_width;
bmpp->height = info_header.bmp_height;
return 0;
}
/* guess which type of DIB header it is and handle it or not */
static int stegmp_parse_dib_header(const unsigned char *addr, size_t size,
struct bitmap *bmpp)
{
uint32_t dib_size;
if (size < sizeof(typeof(dib_size))) {
bmp_errno = BMP_EINVALSIZ;
return -1;
}
dib_size = *((typeof(dib_size) *)addr);
switch (dib_size) {
case 12:
case 52:
case 56:
case 64:
case 108:
case 124:
bmp_errno = BMP_ENOTSUPP;
return -1;
case 40:
return stegmp_parse_windows_bitmap_info_header(addr, size, bmpp);
default:
bmp_errno = BMP_ENOTBMP;
return -1;
}
}
/* parse the main header of the bmp file */
static int stegmp_parse_headers(const unsigned char *addr, size_t orig_size,
struct bitmap *bmpp)
{
struct packed_bmp_header packed_header;
if (orig_size < sizeof(packed_header)) {
bmp_errno = BMP_ENOTBMP;
return -1;
}
packed_header = *((typeof(packed_header) *)addr);
switch (packed_header.magic) {
case BMP_MAGIC_BM:
break;
case BMP_MAGIC_BA:
case BMP_MAGIC_CI:
case BMP_MAGIC_CP:
case BMP_MAGIC_IC:
case BMP_MAGIC_PT:
bmp_errno = BMP_ENOTSUPP;
return -1;
default:
bmp_errno = BMP_ENOTBMP;
return -1;
}
if (packed_header.bmp_size != orig_size) {
bmp_errno = BMP_EINVALSIZ;
return -1;
}
bmpp->data_offset = packed_header.data_offset;
bmpp->size = packed_header.bmp_size;
stegmp_parse_dib_header(addr + sizeof(packed_header), orig_size, bmpp);
return 0;
}
/*
* if `input' is NULL, we, want to read bmp_file
*/
static int stegmp(const char *bmp_file, FILE *input)
{
void *addr;
struct stat stat;
struct bitmap bmp;
FILE *fh = fopen(bmp_file, "r+");
if (fh == NULL) {
fprintf(stderr, "%s: %m\n", bmp_file);
return -1;
}
fstat(fileno(fh), &stat);
addr = mmap(NULL, stat.st_size, PROT_READ | ((input) ? PROT_WRITE : 0),
MAP_SHARED, fileno(fh), 0);
if (addr == MAP_FAILED) {
fprintf(stderr, "%s: %m\n", bmp_file);
fclose(fh);
return -1;
}
/* retrieve the required information (i.e. width, height, bpp .. ) */
if (stegmp_parse_headers(addr, stat.st_size, &bmp) >= 0) {
(void) input;
} else {
fprintf(stderr, "unable to parse headers: %s\n",
bmp_strerror(bmp_errno));
}
munmap(addr, stat.st_size);
fclose(fh);
return 0;
}
static inline int stegmp_read(const char *bmp_file)
{
return stegmp(bmp_file, NULL);
}
static int stegmp_write(const char *bmp_file, const char *in_file)
{
if (strcmp(in_file, "-") == 0) {
return stegmp(bmp_file, stdin);
} else {
int ret;
FILE *fh = fopen(in_file, "r");
if (fh == NULL) {
fprintf(stderr, "%s: %m\n", in_file);
return -1;
}
ret = stegmp(bmp_file, fh);
fclose(fh);
return ret;
}
}
__attribute__((noreturn))
static void usage(const char *prgnam)
{
fprintf(stderr, "usage: %s COMMAND\n", prgnam);
fprintf(stderr, "\nCOMMAND\n");
fprintf(stderr, " read BMP\n");
fprintf(stderr, " write BMP in_file\n");
exit(EX_USAGE);
}
int main(int argc, char *argv[])
{
/* we need a file passed as argument since we want to map it */
if (argc < 3) {
usage(argv[0]);
}
if (strcmp(argv[1], "read") == 0) {
/* read */
return stegmp_read(argv[2]);
} else if (strcmp(argv[1], "write") == 0) {
/* write */
if (argc < 4) {
usage(argv[0]);
}
return stegmp_write(argv[2], argv[3]);
} else {
usage(argv[0]);
}
}
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