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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
/* Lzip - LZMA lossless data compressor
Copyright (C) 2008-2024 Antonio Diaz Diaz.
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, see <http://www.gnu.org/licenses/>.
*/
#define _FILE_OFFSET_BITS 64
#include <algorithm>
#include <cerrno>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include <stdint.h>
#include <unistd.h>
#include "lzip.h"
#include "lzip_index.h"
namespace {
int seek_read( const int fd, uint8_t * const buf, const int size,
const long long pos )
{
if( lseek( fd, pos, SEEK_SET ) == pos )
return readblock( fd, buf, size );
return 0;
}
} // end namespace
bool Lzip_index::check_header( const Lzip_header & header )
{
if( !header.check_magic() )
{ error_ = bad_magic_msg; retval_ = 2; return false; }
if( !header.check_version() )
{ error_ = bad_version( header.version() ); retval_ = 2; return false; }
if( !isvalid_ds( header.dictionary_size() ) )
{ error_ = bad_dict_msg; retval_ = 2; return false; }
return true;
}
void Lzip_index::set_errno_error( const char * const msg )
{
error_ = msg; error_ += std::strerror( errno );
retval_ = 1;
}
void Lzip_index::set_num_error( const char * const msg, unsigned long long num )
{
char buf[80];
snprintf( buf, sizeof buf, "%s%llu", msg, num );
error_ = buf;
retval_ = 2;
}
bool Lzip_index::read_header( const int fd, Lzip_header & header,
const long long pos, const bool ignore_marking )
{
if( seek_read( fd, header.data, header.size, pos ) != header.size )
{ set_errno_error( "Error reading member header: " ); return false; }
uint8_t byte;
if( !ignore_marking && readblock( fd, &byte, 1 ) == 1 && byte != 0 )
{ error_ = marking_msg; retval_ = 2; return false; }
return true;
}
// If successful, push last member and set pos to member header.
bool Lzip_index::skip_trailing_data( const int fd, unsigned long long & pos,
const Cl_options & cl_opts )
{
if( pos < min_member_size ) return false;
enum { block_size = 16384,
buffer_size = block_size + Lzip_trailer::size - 1 + Lzip_header::size };
uint8_t buffer[buffer_size];
int bsize = pos % block_size; // total bytes in buffer
if( bsize <= buffer_size - block_size ) bsize += block_size;
int search_size = bsize; // bytes to search for trailer
int rd_size = bsize; // bytes to read from file
unsigned long long ipos = pos - rd_size; // aligned to block_size
while( true )
{
if( seek_read( fd, buffer, rd_size, ipos ) != rd_size )
{ set_errno_error( "Error seeking member trailer: " ); return false; }
const uint8_t max_msb = ( ipos + search_size ) >> 56;
for( int i = search_size; i >= Lzip_trailer::size; --i )
if( buffer[i-1] <= max_msb ) // most significant byte of member_size
{
const Lzip_trailer & trailer =
*(const Lzip_trailer *)( buffer + i - trailer.size );
const unsigned long long member_size = trailer.member_size();
if( member_size == 0 ) // skip trailing zeros
{ while( i > trailer.size && buffer[i-9] == 0 ) --i; continue; }
if( member_size > ipos + i || !trailer.check_consistency() ) continue;
Lzip_header header;
if( !read_header( fd, header, ipos + i - member_size,
cl_opts.ignore_marking ) ) return false;
if( !header.check() ) continue;
const Lzip_header & header2 = *(const Lzip_header *)( buffer + i );
const bool full_h2 = bsize - i >= header.size;
if( header2.check_prefix( bsize - i ) ) // last member
{
if( !full_h2 ) error_ = "Last member in input file is truncated.";
else if( check_header( header2 ) )
error_ = "Last member in input file is truncated or corrupt.";
retval_ = 2; return false;
}
if( !cl_opts.loose_trailing && full_h2 && header2.check_corrupt() )
{ error_ = corrupt_mm_msg; retval_ = 2; return false; }
if( !cl_opts.ignore_trailing )
{ error_ = trailing_msg; retval_ = 2; return false; }
const unsigned long long data_size = trailer.data_size();
if( !cl_opts.ignore_empty && data_size == 0 )
{ error_ = empty_msg; retval_ = 2; return false; }
pos = ipos + i - member_size; // good member
const unsigned dictionary_size = header.dictionary_size();
if( dictionary_size_ < dictionary_size )
dictionary_size_ = dictionary_size;
member_vector.push_back( Member( 0, data_size, pos, member_size,
dictionary_size ) );
return true;
}
if( ipos == 0 )
{ set_num_error( "Bad trailer at pos ", pos - Lzip_trailer::size );
return false; }
bsize = buffer_size;
search_size = bsize - Lzip_header::size;
rd_size = block_size;
ipos -= rd_size;
std::memcpy( buffer + rd_size, buffer, buffer_size - rd_size );
}
}
Lzip_index::Lzip_index( const int infd, const Cl_options & cl_opts )
: insize( lseek( infd, 0, SEEK_END ) ), retval_( 0 ), dictionary_size_( 0 )
{
if( insize < 0 )
{ set_errno_error( "Input file is not seekable: " ); return; }
if( insize < min_member_size )
{ error_ = "Input file is too short."; retval_ = 2; return; }
if( insize > INT64_MAX )
{ error_ = "Input file is too long (2^63 bytes or more).";
retval_ = 2; return; }
Lzip_header header;
if( !read_header( infd, header, 0, cl_opts.ignore_marking ) ||
!check_header( header ) ) return;
unsigned long long pos = insize; // always points to a header or to EOF
while( pos >= min_member_size )
{
Lzip_trailer trailer;
if( seek_read( infd, trailer.data, trailer.size, pos - trailer.size ) !=
trailer.size )
{ set_errno_error( "Error reading member trailer: " ); break; }
const unsigned long long member_size = trailer.member_size();
if( member_size > pos || !trailer.check_consistency() ) // bad trailer
{
if( member_vector.empty() )
{ if( skip_trailing_data( infd, pos, cl_opts ) ) continue; return; }
set_num_error( "Bad trailer at pos ", pos - trailer.size ); break;
}
if( !read_header( infd, header, pos - member_size, cl_opts.ignore_marking ) )
break;
if( !header.check() ) // bad header
{
if( member_vector.empty() )
{ if( skip_trailing_data( infd, pos, cl_opts ) ) continue; return; }
set_num_error( "Bad header at pos ", pos - member_size ); break;
}
const unsigned long long data_size = trailer.data_size();
if( !cl_opts.ignore_empty && data_size == 0 )
{ error_ = empty_msg; retval_ = 2; break; }
pos -= member_size; // good member
const unsigned dictionary_size = header.dictionary_size();
if( dictionary_size_ < dictionary_size )
dictionary_size_ = dictionary_size;
member_vector.push_back( Member( 0, data_size, pos, member_size,
dictionary_size ) );
}
if( pos != 0 || member_vector.empty() || retval_ != 0 )
{
member_vector.clear();
if( retval_ == 0 ) { error_ = "Can't create file index."; retval_ = 2; }
return;
}
std::reverse( member_vector.begin(), member_vector.end() );
for( unsigned long i = 0; ; ++i )
{
const long long end = member_vector[i].dblock.end();
if( end < 0 || end > INT64_MAX )
{
member_vector.clear();
error_ = "Data in input file is too long (2^63 bytes or more).";
retval_ = 2; return;
}
if( i + 1 >= member_vector.size() ) break;
member_vector[i+1].dblock.pos( end );
}
}
|
