1 files changed, 149 insertions, 0 deletions
diff --git a/alone_to_lz.cc b/alone_to_lz.cc
new file mode 100644
index 0000000..9e5b330
--- /dev/null
+++ b/alone_to_lz.cc
@@ -0,0 +1,149 @@
+/* Lziprecover - Data recovery tool for the lzip format
+   Copyright (C) 2009-2022 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 <climits>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <new>
+#include <string>
+#include <vector>
+#include <stdint.h>
+#include <unistd.h>
+
+#include "lzip.h"
+#include "mtester.h"
+
+
+namespace {
+
+/* Return the address of a malloc'd buffer containing the file data and
+   the file size in '*size'. The buffer is at least 20 bytes larger.
+   In case of error, return 0 and do not modify '*size'.
+*/
+uint8_t * read_file( const int infd, long * const size,
+                     const char * const filename )
+  {
+  long buffer_size = 1 << 20;
+  uint8_t * buffer = (uint8_t *)std::malloc( buffer_size );
+  if( !buffer ) throw std::bad_alloc();
+
+  long file_size = readblock( infd, buffer, buffer_size - 20 );
+  while( file_size >= buffer_size - 20 && !errno )
+    {
+    if( buffer_size >= LONG_MAX )
+      { show_file_error( filename, "File is too large" ); std::free( buffer );
+        return 0; }
+    buffer_size = ( buffer_size <= LONG_MAX / 2 ) ? 2 * buffer_size : LONG_MAX;
+    uint8_t * const tmp = (uint8_t *)std::realloc( buffer, buffer_size );
+    if( !tmp ) { std::free( buffer ); throw std::bad_alloc(); }
+    buffer = tmp;
+    file_size +=
+      readblock( infd, buffer + file_size, buffer_size - 20 - file_size );
+    }
+  if( errno )
+    {
+    show_file_error( filename, "Error reading file", errno );
+    std::free( buffer ); return 0;
+    }
+  *size = file_size;
+  return buffer;
+  }
+
+
+bool validate_ds( unsigned * const dictionary_size )
+  {
+  if( *dictionary_size < min_dictionary_size )
+    { *dictionary_size = min_dictionary_size; return false; }
+  if( *dictionary_size > max_dictionary_size )
+    { *dictionary_size = max_dictionary_size; return false; }
+  return true;
+  }
+
+} // end namespace
+
+
+int alone_to_lz( const int infd, const Pretty_print & pp )
+  {
+  enum { lzma_header_size = 13, offset = lzma_header_size - Lzip_header::size };
+  long file_size = 0;
+  uint8_t * const buffer = read_file( infd, &file_size, pp.name() );
+  if( !buffer ) return 1;
+  if( file_size < lzma_header_size )
+    { show_file_error( pp.name(), "file is too short" );
+      std::free( buffer ); return 2; }
+
+  if( buffer[0] != 93 )			// (45 * 2) + (9 * 0) + 3
+    {
+    const Lzip_header & header = *(const Lzip_header *)buffer;
+    if( header.verify_magic() && header.verify_version() &&
+        isvalid_ds( header.dictionary_size() ) )
+      show_file_error( pp.name(), "file is already in lzip format" );
+    else
+      show_file_error( pp.name(), "file has non-default LZMA properties" );
+    std::free( buffer ); return 2;
+    }
+  for( int i = 5; i < 13; ++i ) if( buffer[i] != 0xFF )
+    { show_file_error( pp.name(), "file is non-streamed" );
+      std::free( buffer ); return 2; }
+
+  if( verbosity >= 1 ) pp();
+  unsigned dictionary_size = 0;
+  for( int i = 4; i > 0; --i )
+    { dictionary_size <<= 8; dictionary_size += buffer[i]; }
+  const unsigned orig_dictionary_size = dictionary_size;
+  validate_ds( &dictionary_size );
+  Lzip_header & header = *(Lzip_header *)( buffer + offset );
+  header.set_magic();
+  header.dictionary_size( dictionary_size );
+  for( int i = 0; i < Lzip_trailer::size; ++i ) buffer[file_size++] = 0;
+  {
+  LZ_mtester mtester( buffer + offset, file_size - offset, dictionary_size );
+  const int result = mtester.test_member();
+  if( result == 1 && orig_dictionary_size > max_dictionary_size )
+    { pp( "dictionary size is too large" ); std::free( buffer ); return 2; }
+  if( result != 3 || !mtester.finished() )
+    { pp( "file is corrupt" ); std::free( buffer ); return 2; }
+  if( mtester.max_distance() < dictionary_size &&
+      dictionary_size > min_dictionary_size )
+    {
+    dictionary_size =
+      std::max( mtester.max_distance(), (unsigned)min_dictionary_size );
+    header.dictionary_size( dictionary_size );
+    }
+  Lzip_trailer & trailer =
+    *(Lzip_trailer *)( buffer + file_size - Lzip_trailer::size );
+  trailer.data_crc( mtester.crc() );
+  trailer.data_size( mtester.data_position() );
+  trailer.member_size( mtester.member_position() );
+  }
+  LZ_mtester mtester( buffer + offset, file_size - offset, dictionary_size );
+  if( mtester.test_member() != 0 || !mtester.finished() )
+    { pp( "conversion failed" ); std::free( buffer ); return 2; }
+  if( writeblock( outfd, buffer + offset, file_size - offset ) != file_size - offset )
+    {
+    show_error( "Error writing output file", errno );
+    std::free( buffer ); return 1;
+    }
+  std::free( buffer );
+  if( verbosity >= 1 ) std::fputs( "done\n", stderr );
+  return 0;
+  }