diff options
Diffstat (limited to 'repair.cc')
| -rw-r--r-- | repair.cc | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/repair.cc b/repair.cc new file mode 100644 index 0000000..8a92e59 --- /dev/null +++ b/repair.cc @@ -0,0 +1,114 @@ +/* Lziprecover - Data recovery tool for lzipped files + Copyright (C) 2009, 2010, 2011 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 3 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 <cerrno> +#include <climits> +#include <cstdio> +#include <cstring> +#include <string> +#include <vector> +#include <stdint.h> +#include <sys/stat.h> + +#include "lzip.h" + + +int repair_file( const std::string & input_filename, + const std::string & output_filename, const bool force ) + { + struct stat in_stats; + const int infd = open_instream( input_filename, &in_stats, true, true ); + if( infd < 0 ) return 1; + const long long isize = lseek( infd, 0, SEEK_END ); + if( isize < 0 ) + { show_error( "Input file is not seekable", errno ); return 1; } + if( isize < 36 ) + { show_error( "Input file is too short." ); return 2; } + if( !verify_single_member( infd, isize ) ) return 2; + if( lseek( infd, 0, SEEK_SET ) < 0 ) + { show_error( "Seek error in input file", errno ); return 1; } + + long long failure_pos = 0; + if( try_decompress( infd, isize, &failure_pos ) ) + { + if( verbosity >= 1 ) + std::printf( "Input file has no errors. Recovery is not needed.\n" ); + return 0; + } + if( failure_pos >= isize - 8 ) failure_pos = isize - 8 - 1; + if( failure_pos < File_header::size ) + { show_error( "Can't repair error in input file." ); return 2; } + + if( lseek( infd, 0, SEEK_SET ) < 0 ) + { show_error( "Seek error in input file", errno ); return 1; } + + const int outfd = open_outstream_rw( output_filename, force ); + if( outfd < 0 ) { close( infd ); return 1; } + if( !copy_file( infd, outfd ) ) + cleanup_and_fail( output_filename, outfd, 1 ); + + const long long min_pos = + std::max( (long long)File_header::size, failure_pos - 1000 ); + bool done = false; + for( long long pos = failure_pos; pos >= min_pos; --pos ) + { + if( verbosity >= 1 ) + { + std::printf( "Trying position %lld \r", pos ); + std::fflush( stdout ); + } + uint8_t byte; + if( lseek( outfd, pos, SEEK_SET ) < 0 || + readblock( outfd, &byte, 1 ) != 1 ) + { show_error( "Error reading output file", errno ); + cleanup_and_fail( output_filename, outfd, 1 ); } + for( int i = 0; i < 255; ++i ) + { + ++byte; + if( lseek( outfd, pos, SEEK_SET ) < 0 || + writeblock( outfd, &byte, 1 ) != 1 || + lseek( outfd, 0, SEEK_SET ) < 0 ) + { show_error( "Error writing output file", errno ); + cleanup_and_fail( output_filename, outfd, 1 ); } + if( try_decompress( outfd, isize ) ) + { done = true; break; } + } + if( done ) break; + ++byte; + if( lseek( outfd, pos, SEEK_SET ) < 0 || + writeblock( outfd, &byte, 1 ) != 1 ) + { show_error( "Error writing output file", errno ); + cleanup_and_fail( output_filename, outfd, 1 ); } + } + if( verbosity >= 1 ) std::printf( "\n" ); + + if( close( outfd ) != 0 ) + { + show_error( "Error closing output file", errno ); + cleanup_and_fail( output_filename, -1, 1 ); + } + if( !done ) + { + show_error( "Error is larger than 1 byte. Can't repair input file." ); + cleanup_and_fail( output_filename, -1, 2 ); + } + if( verbosity >= 1 ) + std::printf( "Copy of input file repaired successfully.\n" ); + return 0; + } |