/* Lunzip - Decompressor for the lzip format
Copyright (C) 2010-2019 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 .
*/
#define _FILE_OFFSET_BITS 64
#include
#include
#include
#include
#include
#include
#include
#include "lzip.h"
#include "lzip_index.h"
static 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;
}
static bool add_error( struct Lzip_index * const li, const char * const msg )
{
const int len = strlen( msg );
void * tmp = resize_buffer( li->error, li->error_size + len + 1 );
if( !tmp ) return false;
li->error = (char *)tmp;
strncpy( li->error + li->error_size, msg, len + 1 );
li->error_size += len;
return true;
}
static bool push_back_member( struct Lzip_index * const li,
const long long dp, const long long ds,
const long long mp, const long long ms,
const unsigned dict_size )
{
struct Member * p;
void * tmp = resize_buffer( li->member_vector,
( li->members + 1 ) * sizeof li->member_vector[0] );
if( !tmp )
{ add_error( li, "Not enough memory." ); li->retval = 1; return false; }
li->member_vector = (struct Member *)tmp;
p = &(li->member_vector[li->members]);
init_member( p, dp, ds, mp, ms, dict_size );
++li->members;
return true;
}
static void Li_free_member_vector( struct Lzip_index * const li )
{
if( li->member_vector )
{ free( li->member_vector ); li->member_vector = 0; }
li->members = 0;
}
static void Li_reverse_member_vector( struct Lzip_index * const li )
{
struct Member tmp;
long i;
for( i = 0; i < li->members / 2; ++i )
{
tmp = li->member_vector[i];
li->member_vector[i] = li->member_vector[li->members-i-1];
li->member_vector[li->members-i-1] = tmp;
}
}
static void Li_set_errno_error( struct Lzip_index * const li,
const char * const msg )
{
add_error( li, msg ); add_error( li, strerror( errno ) );
li->retval = 1;
}
static void Li_set_num_error( struct Lzip_index * const li,
const char * const msg, unsigned long long num )
{
char buf[80];
snprintf( buf, sizeof buf, "%s%llu", msg, num );
add_error( li, buf );
li->retval = 2;
}
/* If successful, push last member and set pos to member header. */
static bool Li_skip_trailing_data( struct Lzip_index * const li,
const int fd, long long * const pos,
const bool ignore_trailing,
const bool loose_trailing )
{
enum { block_size = 16384,
buffer_size = block_size + Lt_size - 1 + Lh_size };
uint8_t buffer[buffer_size];
int bsize = *pos % block_size; /* total bytes in buffer */
int search_size, rd_size;
unsigned long long ipos;
int i;
if( *pos < min_member_size ) return false;
if( bsize <= buffer_size - block_size ) bsize += block_size;
search_size = bsize; /* bytes to search for trailer */
rd_size = bsize; /* bytes to read from file */
ipos = *pos - rd_size; /* aligned to block_size */
while( true )
{
const uint8_t max_msb = ( ipos + search_size ) >> 56;
if( seek_read( fd, buffer, rd_size, ipos ) != rd_size )
{ Li_set_errno_error( li, "Error seeking member trailer: " );
return false; }
for( i = search_size; i >= Lt_size; --i )
if( buffer[i-1] <= max_msb ) /* most significant byte of member_size */
{
Lzip_header header;
const Lzip_trailer * const trailer =
(const Lzip_trailer *)( buffer + i - Lt_size );
const unsigned long long member_size = Lt_get_member_size( *trailer );
unsigned dictionary_size;
if( member_size == 0 ) /* skip trailing zeros */
{ while( i > Lt_size && buffer[i-9] == 0 ) --i; continue; }
if( member_size > ipos + i || !Lt_verify_consistency( *trailer ) )
continue;
if( seek_read( fd, header, Lh_size,
ipos + i - member_size ) != Lh_size )
{ Li_set_errno_error( li, "Error reading member header: " );
return false; }
dictionary_size = Lh_get_dictionary_size( header );
if( !Lh_verify_magic( header ) || !Lh_verify_version( header ) ||
!isvalid_ds( dictionary_size ) ) continue;
if( Lh_verify_prefix( buffer + i, bsize - i ) )
{
add_error( li, "Last member in input file is truncated or corrupt." );
li->retval = 2; return false;
}
if( !loose_trailing && bsize - i >= Lh_size &&
Lh_verify_corrupt( buffer + i ) )
{ add_error( li, corrupt_mm_msg ); li->retval = 2; return false; }
if( !ignore_trailing )
{ add_error( li, trailing_msg ); li->retval = 2; return false; }
*pos = ipos + i - member_size;
return push_back_member( li, 0, Lt_get_data_size( *trailer ), *pos,
member_size, dictionary_size );
}
if( ipos <= 0 )
{ Li_set_num_error( li, "Bad trailer at pos ", *pos - Lt_size );
return false; }
bsize = buffer_size;
search_size = bsize - Lh_size;
rd_size = block_size;
ipos -= rd_size;
memcpy( buffer + rd_size, buffer, buffer_size - rd_size );
}
}
bool Li_init( struct Lzip_index * const li, const int infd,
const bool ignore_trailing, const bool loose_trailing )
{
Lzip_header header;
long long pos;
long i;
li->member_vector = 0;
li->error = 0;
li->insize = lseek( infd, 0, SEEK_END );
li->members = 0;
li->error_size = 0;
li->retval = 0;
if( li->insize < 0 )
{ Li_set_errno_error( li, "Input file is not seekable: " ); return false; }
if( li->insize < min_member_size )
{ add_error( li, "Input file is too short." ); li->retval = 2;
return false; }
if( li->insize > INT64_MAX )
{ add_error( li, "Input file is too long (2^63 bytes or more)." );
li->retval = 2; return false; }
if( seek_read( infd, header, Lh_size, 0 ) != Lh_size )
{ Li_set_errno_error( li, "Error reading member header: " ); return false; }
if( !Lh_verify_magic( header ) )
{ add_error( li, bad_magic_msg ); li->retval = 2; return false; }
if( !Lh_verify_version( header ) )
{ add_error( li, bad_version( Lh_version( header ) ) ); li->retval = 2;
return false; }
if( !isvalid_ds( Lh_get_dictionary_size( header ) ) )
{ add_error( li, bad_dict_msg ); li->retval = 2; return false; }
pos = li->insize; /* always points to a header or to EOF */
while( pos >= min_member_size )
{
Lzip_trailer trailer;
unsigned long long member_size;
unsigned dictionary_size;
if( seek_read( infd, trailer, Lt_size, pos - Lt_size ) != Lt_size )
{ Li_set_errno_error( li, "Error reading member trailer: " ); break; }
member_size = Lt_get_member_size( trailer );
if( member_size > (unsigned long long)pos || !Lt_verify_consistency( trailer ) )
{
if( li->members <= 0 )
{ if( Li_skip_trailing_data( li, infd, &pos, ignore_trailing,
loose_trailing ) ) continue; else return false; }
Li_set_num_error( li, "Bad trailer at pos ", pos - Lt_size );
break;
}
if( seek_read( infd, header, Lh_size, pos - member_size ) != Lh_size )
{ Li_set_errno_error( li, "Error reading member header: " ); break; }
dictionary_size = Lh_get_dictionary_size( header );
if( !Lh_verify_magic( header ) || !Lh_verify_version( header ) ||
!isvalid_ds( dictionary_size ) )
{
if( li->members <= 0 )
{ if( Li_skip_trailing_data( li, infd, &pos, ignore_trailing,
loose_trailing ) ) continue; else return false; }
Li_set_num_error( li, "Bad header at pos ", pos - member_size );
break;
}
pos -= member_size;
if( !push_back_member( li, 0, Lt_get_data_size( trailer ), pos,
member_size, dictionary_size ) )
return false;
}
if( pos != 0 || li->members <= 0 )
{
Li_free_member_vector( li );
if( li->retval == 0 )
{ add_error( li, "Can't create file index." ); li->retval = 2; }
return false;
}
Li_reverse_member_vector( li );
for( i = 0; ; ++i )
{
const long long end = block_end( li->member_vector[i].dblock );
if( end < 0 || end > INT64_MAX )
{
Li_free_member_vector( li );
add_error( li, "Data in input file is too long (2^63 bytes or more)." );
li->retval = 2; return false;
}
if( i + 1 >= li->members ) break;
li->member_vector[i+1].dblock.pos = end;
}
return true;
}
void Li_free( struct Lzip_index * const li )
{
Li_free_member_vector( li );
if( li->error ) { free( li->error ); li->error = 0; }
li->error_size = 0;
}