summaryrefslogtreecommitdiffstats
path: root/src/file_bac.c
blob: c4514f2baf1a06767bbdc06733d9c678cbdb8da4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
/*

    File: file_bac.c

    Copyright (C) 2009 Christophe GRENIER <grenier@cgsecurity.org>
  
    This software 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 the Free Software Foundation, Inc., 51
    Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_bac)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"
#include "common.h"
#include "log.h"
#include "memmem.h"

/*@
  @ requires \valid(file_stat);
  @*/
static void register_header_check_bac(file_stat_t *file_stat);

const file_hint_t file_hint_bac= {
  .extension="bac",
  .description="Bacula backup",
  .max_filesize=PHOTOREC_MAX_FILE_SIZE,
  .recover=1,
  .enable_by_default=1,
  .register_header_check=&register_header_check_bac
};

struct block_header
{
  uint32_t CheckSum;                /* Block check sum */
  uint32_t BlockSize;               /* Block byte size including the header */
  uint32_t BlockNumber;             /* Block number */
  char ID[4];              	    /* Identification and block level */
  uint32_t VolSessionId;            /* Session Id for Job */
  uint32_t VolSessionTime;          /* Session Time for Job */
} __attribute__ ((gcc_struct, __packed__));

/*@
  @ requires buffer_size >= 2*0x18;
  @ requires (buffer_size&1)==0;
  @ requires \valid_read(buffer+(0..buffer_size-1));
  @ requires \valid(file_recovery);
  @ requires file_recovery->data_check==&data_check_bac;
  @ requires \separated(buffer, file_recovery);
  @ ensures \result == DC_CONTINUE || \result == DC_STOP;
  @ assigns file_recovery->calculated_file_size;
  @*/
static data_check_t data_check_bac(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
  if(buffer_size < 2*0x18)
  {
    file_recovery->data_check=NULL;
    file_recovery->file_check=NULL;
    return DC_CONTINUE;
  }
  /*@
    @ loop assigns file_recovery->calculated_file_size;
    @*/
  while(file_recovery->calculated_file_size + buffer_size/2  >= file_recovery->file_size &&
      file_recovery->calculated_file_size + 0x18 < file_recovery->file_size + buffer_size/2)
  {
    const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
    const struct block_header *hdr=(const struct block_header *)&buffer[i];
    const unsigned int block_size=be32(hdr->BlockSize);
#ifdef DEBUG_BACULA
    const unsigned int block_nbr=be32(hdr->BlockNumber);
    log_trace("file_bac.c: block %u size %u, calculated_file_size %llu\n",
	block_nbr, block_size,
	(long long unsigned)file_recovery->calculated_file_size);
#endif
    if(memcmp(hdr->ID, "BB02", 4)!=0 || block_size<0x18)
    {
#ifndef __FRAMAC__
      log_error("file_bac.c: invalid block at %llu\n",
	  (long long unsigned)file_recovery->calculated_file_size);
#endif
      return DC_STOP;
    }
    file_recovery->calculated_file_size+=(uint64_t)block_size;
  }
#ifdef DEBUG_BACULA
  log_trace("file_bac.c: new calculated_file_size %llu\n",
      (long long unsigned)file_recovery->calculated_file_size);
#endif
  return DC_CONTINUE;
}

/*@
  @ requires buffer_size >= sizeof(struct block_header);
  @ requires \valid_read(buffer+(0..buffer_size-1));
  @ requires \valid_read(file_recovery);
  @ requires file_recovery->file_stat==\null || valid_read_string((char*)file_recovery->filename);
  @ requires \valid(file_recovery_new);
  @ requires file_recovery_new->blocksize > 0;
  @ requires separation: \separated(&file_hint_bac, buffer, file_recovery, file_recovery_new);
  @ ensures \result == 0 || \result == 1;
  @ ensures (\result == 1) ==> (file_recovery_new->file_stat == \null);
  @ ensures (\result == 1) ==> (file_recovery_new->handle == \null);
  @ ensures (\result == 1) ==> (file_recovery_new->time == 0);
  @ ensures (\result == 1) ==> (file_recovery_new->file_size == 0);
  @ ensures (\result == 1) ==> (file_recovery_new->calculated_file_size == 0);
  @ ensures (\result == 1) ==> (file_recovery_new->data_check == \null || file_recovery_new->data_check == &data_check_bac);
  @ ensures (\result == 1) ==> (file_recovery_new->file_check == \null || file_recovery_new->file_check == &file_check_size);
  @ ensures (\result == 1) ==> (file_recovery_new->extension == file_hint_bac.extension);
  @*/
static int header_check_bac(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)
{
  const struct block_header *hdr=(const struct block_header *)buffer;
  if(be32(hdr->BlockSize) < 0x18)
    return 0;
  reset_file_recovery(file_recovery_new);
  file_recovery_new->extension=file_hint_bac.extension;
  file_recovery_new->min_filesize=be32(hdr->BlockSize);
  file_recovery_new->calculated_file_size=0;
  if(file_recovery_new->blocksize >= 0x18)
  {
    file_recovery_new->data_check=&data_check_bac;
    file_recovery_new->file_check=&file_check_size;
  }
  return 1;
}

static void register_header_check_bac(file_stat_t *file_stat)
{
  static const unsigned char bac_header[8]={ 0, 0, 0, 0, 'B', 'B', '0', '2' };
  register_header_check(8, bac_header, sizeof(bac_header), &header_check_bac, file_stat);
}
#endif