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
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/*
File: file_mid.c
Copyright (C) 1998-2007 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_mid)
#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"
/*@ requires \valid(file_stat); */
static void register_header_check_mid(file_stat_t *file_stat);
const file_hint_t file_hint_mid= {
.extension="mid",
.description="MIDI Musical Instrument Digital Interface",
.max_filesize=50*1024*1024,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_mid
};
/* See http://www.sonicspot.com/guide/midifiles.html for more information about MIDI file format */
struct midi_header
{
char magic[4];
uint32_t len; /* = 6 */
uint16_t format;
uint16_t tracks;
int16_t time_division;
} __attribute__ ((gcc_struct, __packed__));
/*@
@ requires valid_file_recovery(file_recovery);
@ requires \valid(file_recovery->handle);
@ requires file_recovery->file_check == &file_check_midi;
@ requires separation: \separated(file_recovery, file_recovery->handle, &errno, &Frama_C_entropy_source);
@ assigns errno;
@ assigns file_recovery->calculated_file_size;
@ assigns file_recovery->file_size;
@ assigns *file_recovery->handle;
@ assigns file_recovery->time;
@ assigns Frama_C_entropy_source;
@*/
static void file_check_midi(file_recovery_t *file_recovery)
{
const uint64_t fs_org=file_recovery->file_size;
struct midi_header hdr;
unsigned int i;
unsigned int tracks;
uint64_t fs=4+4+6;
file_recovery->file_size=0;
if(my_fseek(file_recovery->handle, 0, SEEK_SET) < 0 ||
fread(&hdr, sizeof(hdr), 1, file_recovery->handle) != 1)
return ;
tracks=be16(hdr.tracks);
/*@
@ loop assigns i, *file_recovery->handle, fs;
@ loop assigns errno, Frama_C_entropy_source;
@*/
for(i=0; i<tracks; i++)
{
struct midi_header track;
#ifdef DEBUG_MIDI
log_info("file_check_midi 0x%08llx\n", (unsigned long long)fs);
#endif
if(my_fseek(file_recovery->handle, fs, SEEK_SET) < 0 ||
fread(&track, 8, 1, file_recovery->handle) != 1 ||
memcmp(&track.magic[0], "MTrk", 4)!=0)
return ;
fs+=(uint64_t)8+be32(track.len);
}
if(fs_org < fs)
return ;
file_recovery->file_size=fs;
}
/*@
@ requires buffer_size >= 2 && (buffer_size&1)==0;
@ requires \valid(file_recovery);
@ requires \valid_read(buffer + ( 0 .. buffer_size-1));
@ requires file_recovery->data_check == &data_check_midi;
@ requires separation: \separated(buffer+(..), file_recovery);
@ ensures \result == DC_CONTINUE || \result == DC_STOP;
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_midi(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
/*@
@ 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 + 8 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
/*@ assert 0 <= i < buffer_size - 8; */
const struct midi_header *hdr=(const struct midi_header*)&buffer[i];
const uint64_t len=be32(hdr->len);
#ifdef DEBUG_MIDI
log_info("data_check_midi 0x%08llx len=%llu\n", (long long unsigned)file_recovery->calculated_file_size, (long long unsigned)len);
#endif
if(memcmp(&hdr->magic[0], "MTrk", 4)!=0)
return DC_STOP;
file_recovery->calculated_file_size+=(uint64_t)8+len;
}
return DC_CONTINUE;
}
/*@
@ requires buffer_size >= sizeof(struct midi_header);
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires valid_file_recovery(file_recovery);
@ requires \valid(file_recovery_new);
@ requires file_recovery_new->blocksize > 0;
@ requires separation: \separated(&file_hint_mid, buffer+(..), file_recovery, file_recovery_new);
@ assigns *file_recovery_new;
@ ensures \result == 0 || \result == 1;
@ ensures \result!=0 ==> valid_file_recovery(file_recovery_new);
@*/
static int header_check_mid(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 midi_header *hdr=(const struct midi_header *)buffer;
if(be16(hdr->format) > 2 || be16(hdr->tracks) == 0)
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_mid.extension;
file_recovery_new->file_check=&file_check_midi;
if(file_recovery_new->blocksize < 8)
return 1;
file_recovery_new->calculated_file_size=4+4+6;
file_recovery_new->data_check=&data_check_midi;
return 1;
}
static void register_header_check_mid(file_stat_t *file_stat)
{
static const unsigned char mid_header[8] = { 'M','T','h','d', 0, 0, 0, 0x6};
register_header_check(0, mid_header,sizeof(mid_header), &header_check_mid, file_stat);
}
#endif
|
