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Diffstat (limited to 'lunzcrash.cc')
| -rw-r--r-- | lunzcrash.cc | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/lunzcrash.cc b/lunzcrash.cc new file mode 100644 index 0000000..b07b748 --- /dev/null +++ b/lunzcrash.cc @@ -0,0 +1,250 @@ +/* Lziprecover - Data recovery tool for the lzip format + Copyright (C) 2009-2021 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 <string> +#include <vector> +#include <stdint.h> +#include <unistd.h> +#include <sys/stat.h> + +#include "lzip.h" +#include "md5.h" +#include "mtester.h" +#include "lzip_index.h" + + +namespace { + +bool verify_member( const uint8_t * const mbuffer, const long long msize, + const unsigned dictionary_size, const char * const name, + uint8_t digest[16] ) + { + MD5SUM md5sum; + LZ_mtester mtester( mbuffer, msize, dictionary_size, -1, &md5sum ); + if( mtester.test_member() != 0 || !mtester.finished() ) + { show_file_error( name, "Error verifying input file." ); return false; } + md5sum.md5_finish( digest ); + return true; + } + + +bool compare_member( const uint8_t * const mbuffer, const long long msize, + const unsigned dictionary_size, + const long long byte_pos, const uint8_t digest[16] ) + { + MD5SUM md5sum; + LZ_mtester mtester( mbuffer, msize, dictionary_size, -1, &md5sum ); + bool error = ( mtester.test_member() != 0 || !mtester.finished() ); + if( !error ) + { + uint8_t new_digest[16]; + md5sum.md5_finish( new_digest ); + if( std::memcmp( digest, new_digest, 16 ) != 0 ) error = true; + } + if( error && verbosity >= 0 ) + std::printf( "byte %llu comparison failed\n", byte_pos ); + return !error; + } + + +int test_member_rest( const LZ_mtester & master, long * const failure_posp, + const unsigned long long byte_pos ) + { + LZ_mtester mtester( master ); + mtester.duplicate_buffer(); + int result = mtester.test_member( LLONG_MAX, LLONG_MAX, stdout, byte_pos ); + if( result == 0 && !mtester.finished() ) result = -1; + if( result != 0 ) *failure_posp = mtester.member_position(); + return result; + } + + +long next_pct_pos( const Lzip_index & lzip_index, const int i, const int pct ) + { + if( pct <= 0 ) return 0; + const long long cdata_size = lzip_index.cdata_size(); + const long long mpos = lzip_index.mblock( i ).pos(); + const long long msize = lzip_index.mblock( i ).size(); + long long pct_pos = (long long)( cdata_size / ( 100.0 / pct ) ); + + if( pct_pos <= mpos ) pct_pos = 0; + else if( pct_pos == cdata_size ) pct_pos = msize - 21; // 100% + else if( pct_pos >= mpos + msize ) pct_pos = msize; + else pct_pos -= mpos; + return pct_pos; + } + +} // end namespace + + +/* Test 1-bit errors in LZMA streams in file. + Unless verbosity >= 1, print only the bytes with interesting results. */ +int lunzcrash( const std::string & input_filename ) + { + struct stat in_stats; // not used + const int infd = + open_instream( input_filename.c_str(), &in_stats, false, true ); + if( infd < 0 ) return 1; + + const Lzip_index lzip_index( infd, true, true ); + if( lzip_index.retval() != 0 ) + { show_file_error( input_filename.c_str(), lzip_index.error().c_str() ); + return lzip_index.retval(); } + if( verbosity >= 2 ) printf( "Testing file '%s'\n", input_filename.c_str() ); + + const long long cdata_size = lzip_index.cdata_size(); + long positions = 0, decompressions = 0, successes = 0, failed_comparisons = 0; + int pct = ( cdata_size >= 1000 && isatty( STDERR_FILENO ) ) ? 0 : 100; + for( long i = 0; i < lzip_index.members(); ++i ) + { + const long long mpos = lzip_index.mblock( i ).pos(); + const long long msize = lzip_index.mblock( i ).size(); + const unsigned dictionary_size = lzip_index.dictionary_size( i ); + uint8_t * const mbuffer = read_member( infd, mpos, msize ); + if( !mbuffer ) return 1; + uint8_t md5_orig[16]; + if( !verify_member( mbuffer, msize, dictionary_size, + input_filename.c_str(), md5_orig ) ) return 2; + long pct_pos = next_pct_pos( lzip_index, i, pct ); + long pos = Lzip_header::size + 1, printed = 0; // last pos printed + const long end = msize - 20; + if( verbosity == 0 ) // give a clue of the range being tested + std::printf( "Testing bytes %llu to %llu\n", mpos + pos, mpos + end - 1 ); + LZ_mtester master( mbuffer, msize, dictionary_size ); + for( ; pos < end; ++pos ) + { + const long pos_limit = pos - 16; + if( pos_limit > 0 && master.test_member( pos_limit ) != -1 ) + { show_error( "Can't advance master." ); return 1; } + if( verbosity >= 0 && pos >= pct_pos ) + { std::fprintf( stderr, "\r%3u%% done\r", pct ); ++pct; + pct_pos = next_pct_pos( lzip_index, i, pct ); } + if( verbosity >= 1 ) + { std::printf( "byte %llu\n", mpos + pos ); printed = pos; } + ++positions; + const uint8_t byte = mbuffer[pos]; + for( uint8_t mask = 1; mask != 0; mask <<= 1 ) + { + ++decompressions; + mbuffer[pos] ^= mask; + long failure_pos = 0; + const int result = test_member_rest( master, &failure_pos, + ( printed < pos ) ? mpos + pos : 0 ); + if( result == 0 ) + { + ++successes; + if( verbosity >= 0 ) + { + if( printed < pos ) + { std::printf( "byte %llu\n", mpos + pos ); printed = pos; } + std::printf( "0x%02X (0x%02X^0x%02X) passed the test\n", + mbuffer[pos], byte, mask ); + } + if( !compare_member( mbuffer, msize, dictionary_size, mpos + pos, + md5_orig ) ) ++failed_comparisons; + } + else if( result == 1 ) + { + if( verbosity >= 2 || + ( verbosity >= 1 && failure_pos - pos >= 10000 ) || + ( verbosity >= 0 && failure_pos - pos >= 50000 ) ) + { + if( printed < pos ) + { std::printf( "byte %llu\n", mpos + pos ); printed = pos; } + std::printf( "Decoder error at pos %llu\n", mpos + failure_pos ); + } + } + else if( result == 3 || result == 4 ) // test_member printed the error + { if( verbosity >= 0 && printed < pos ) printed = pos; } + else if( verbosity >= 0 ) + { + if( printed < pos ) + { std::printf( "byte %llu\n", mpos + pos ); printed = pos; } + if( result == 2 ) + std::printf( "File ends unexpectedly at pos %llu\n", + mpos + failure_pos ); + else + std::printf( "Unknown error code '%d'\n", result ); + } + mbuffer[pos] ^= mask; + } + } + delete[] mbuffer; + } + + if( verbosity >= 0 ) + { + std::printf( "\n%8ld bytes tested\n%8ld total decompressions" + "\n%8ld decompressions returned with zero status", + positions, decompressions, successes ); + if( successes > 0 ) + { + if( failed_comparisons > 0 ) + std::printf( ", of which\n%8ld comparisons failed\n", + failed_comparisons ); + else std::fputs( "\n all comparisons passed\n", stdout ); + } + else std::fputc( '\n', stdout ); + } + return 0; + } + + +int md5sum_files( const std::vector< std::string > & filenames ) + { + int retval = 0; + bool stdin_used = false; + + for( unsigned i = 0; i < filenames.size(); ++i ) + { + const bool from_stdin = ( filenames[i] == "-" ); + if( from_stdin ) { if( stdin_used ) continue; else stdin_used = true; } + const char * const input_filename = filenames[i].c_str(); + struct stat in_stats; // not used + const int infd = from_stdin ? STDIN_FILENO : + open_instream( input_filename, &in_stats, false ); + if( infd < 0 ) { set_retval( retval, 1 ); continue; } + + enum { buffer_size = 16384 }; + uint8_t buffer[buffer_size], md5_digest[16]; + MD5SUM md5sum; + while( true ) + { + const int len = readblock( infd, buffer, buffer_size ); + if( len != buffer_size && errno ) throw Error( "Read error" ); + if( len > 0 ) md5sum.md5_update( buffer, len ); + if( len < buffer_size ) break; + } + md5sum.md5_finish( md5_digest ); + if( close( infd ) != 0 ) + { show_file_error( input_filename, "Error closing input file", errno ); + return 1; } + + for( int i = 0; i < 16; ++i ) std::printf( "%02x", md5_digest[i] ); + std::printf( " %s\n", input_filename ); + std::fflush( stdout ); + } + return retval; + } |