1 /*
2 
3     File: file_bvr.c
4 
5     Copyright (C) 2018 Christophe GRENIER <grenier@cgsecurity.org>
6 
7     This software is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11 
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16 
17     You should have received a copy of the GNU General Public License along
18     with this program; if not, write the Free Software Foundation, Inc., 51
19     Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 
21  */
22 
23 #ifdef HAVE_CONFIG_H
24 #include <config.h>
25 #endif
26 #ifdef HAVE_STRING_H
27 #include <string.h>
28 #endif
29 #include <stdio.h>
30 #include "types.h"
31 #include "filegen.h"
32 
33 static void register_header_check_bvr(file_stat_t *file_stat);
34 
35 const file_hint_t file_hint_bvr= {
36   .extension="bvr",
37   .description="Blue Iris DVR",
38   .max_filesize=PHOTOREC_MAX_FILE_SIZE,
39   .recover=1,
40   .enable_by_default=1,
41   .register_header_check=&register_header_check_bvr
42 };
43 
data_check_bvr(const unsigned char * buffer,const unsigned int buffer_size,file_recovery_t * file_recovery)44 static data_check_t data_check_bvr(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
45 {
46   while(file_recovery->calculated_file_size + buffer_size/2  >= file_recovery->file_size &&
47       file_recovery->calculated_file_size + 16 < file_recovery->file_size + buffer_size/2)
48   {
49     const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
50     const uint32_t *valp=(const uint32_t *)&buffer[i+12];
51     if(memcmp(&buffer[i], "BLUE", 4) != 0)
52       return DC_STOP;
53     file_recovery->calculated_file_size+=0x20 + *valp;
54     if(*valp == 0)
55       return DC_STOP;
56   }
57   return DC_CONTINUE;
58 }
59 
header_check_bvr(const unsigned char * buffer,const unsigned int buffer_size,const unsigned int safe_header_only,const file_recovery_t * file_recovery,file_recovery_t * file_recovery_new)60 static int header_check_bvr(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
61 {
62   if(file_recovery->file_stat!=NULL &&
63     file_recovery->file_stat->file_hint==&file_hint_bvr)
64   {
65     header_ignored(file_recovery_new);
66     return 0;
67   }
68   reset_file_recovery(file_recovery_new);
69   file_recovery_new->extension=file_hint_bvr.extension;
70   file_recovery_new->data_check=&data_check_bvr;
71   file_recovery_new->file_check=&file_check_size;
72   return 1;
73 }
74 
register_header_check_bvr(file_stat_t * file_stat)75 static void register_header_check_bvr(file_stat_t *file_stat)
76 {
77   static const unsigned char bvrheader[8]= { 'B', 'L', 'U', 'E', 0x20, 0x00, 0x10, 0x00};
78   register_header_check(0, bvrheader, sizeof(bvrheader), &header_check_bvr, file_stat);
79 }
80