diff options
Diffstat (limited to '')
| -rw-r--r-- | lzip_index.cc (renamed from file_index.cc) | 184 |
1 files changed, 112 insertions, 72 deletions
diff --git a/file_index.cc b/lzip_index.cc index b3d7d70..f70307c 100644 --- a/file_index.cc +++ b/lzip_index.cc @@ -1,5 +1,5 @@ /* Lziprecover - Data recovery tool for the lzip format - Copyright (C) 2009-2018 Antonio Diaz Diaz. + Copyright (C) 2009-2019 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 @@ -27,8 +27,7 @@ #include <unistd.h> #include "lzip.h" -#include "block.h" -#include "file_index.h" +#include "lzip_index.h" int seek_read( const int fd, uint8_t * const buf, const int size, @@ -40,13 +39,13 @@ int seek_read( const int fd, uint8_t * const buf, const int size, } -void File_index::set_errno_error( const char * const msg ) +void Lzip_index::set_errno_error( const char * const msg ) { error_ = msg; error_ += std::strerror( errno ); retval_ = 1; } -void File_index::set_num_error( const char * const msg, unsigned long long num ) +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 ); @@ -54,16 +53,22 @@ void File_index::set_num_error( const char * const msg, unsigned long long num ) retval_ = 2; } - -// If successful, push last member and set pos to member header. -bool File_index::skip_trailing_data( const int fd, long long & pos, - const bool ignore_bad_ds, - const bool ignore_trailing, const bool loose_trailing ) +/* Skip backwards the gap or trailing data ending at pos. + 'ignore_gaps' also ignores format errors and a truncated last member. + If successful, push member preceding gap and set pos to member header. */ +bool Lzip_index::skip_gap( const int fd, long long & pos, + const bool ignore_trailing, const bool loose_trailing, + const bool ignore_bad_ds, const bool ignore_gaps ) { enum { block_size = 16384, - buffer_size = block_size + File_trailer::size - 1 + File_header::size }; + buffer_size = block_size + Lzip_trailer::size - 1 + Lzip_header::size }; uint8_t buffer[buffer_size]; - if( pos < min_member_size ) return false; + if( pos < min_member_size ) + { + if( pos >= 0 && ignore_gaps && !member_vector.empty() ) + { pos = 0; return true; } + return false; + } 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 @@ -75,41 +80,60 @@ bool File_index::skip_trailing_data( const int fd, long long & pos, 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 >= File_trailer::size; --i ) + for( int i = search_size; i >= Lzip_trailer::size; --i ) if( buffer[i-1] <= max_msb ) // most significant byte of member_size { - File_trailer & trailer = - *(File_trailer *)( buffer + i - File_trailer::size ); + const Lzip_trailer & trailer = + *(const Lzip_trailer *)( buffer + i - Lzip_trailer::size ); const unsigned long long member_size = trailer.member_size(); - if( member_size == 0 ) - { while( i > File_trailer::size && buffer[i-9] == 0 ) --i; continue; } - if( member_size < min_member_size || member_size > ipos + i ) + if( member_size == 0 ) // skip trailing zeros + { while( i > Lzip_trailer::size && buffer[i-9] == 0 ) --i; continue; } + if( member_size > ipos + i || !trailer.verify_consistency() ) continue; - File_header header; - if( seek_read( fd, header.data, File_header::size, - ipos + i - member_size ) != File_header::size ) + Lzip_header header; + if( seek_read( fd, header.data, Lzip_header::size, + ipos + i - member_size ) != Lzip_header::size ) { set_errno_error( "Error reading member header: " ); return false; } const unsigned dictionary_size = header.dictionary_size(); if( !header.verify_magic() || !header.verify_version() || ( !ignore_bad_ds && !isvalid_ds( dictionary_size ) ) ) continue; - if( (*(File_header *)( buffer + i )).verify_prefix( bsize - i ) ) - { error_ = "Last member in input file is truncated or corrupt."; - retval_ = 2; return false; } - if( !loose_trailing && bsize - i >= File_header::size && - (*(File_header *)( buffer + i )).verify_corrupt() ) - { error_ = corrupt_mm_msg; retval_ = 2; return false; } - if( !ignore_trailing ) - { error_ = trailing_msg; retval_ = 2; return false; } + if( member_vector.empty() ) // trailing data or truncated member + { + const Lzip_header & last_header = *(const Lzip_header *)( buffer + i ); + if( last_header.verify_prefix( bsize - i ) ) + { + if( !ignore_gaps ) + { error_ = "Last member in input file is truncated or corrupt."; + retval_ = 2; return false; } + const unsigned dictionary_size = + ( bsize - i >= Lzip_header::size ) ? + last_header.dictionary_size() : 0; + const unsigned long long member_size = pos - ( ipos + i ); + pos = ipos + i; + member_vector.push_back( Member( 0, 0, pos, + member_size, dictionary_size ) ); + return true; + } + } + if( !ignore_gaps && member_vector.empty() ) + { + if( !loose_trailing && bsize - i >= Lzip_header::size && + (*(const Lzip_header *)( buffer + i )).verify_corrupt() ) + { error_ = corrupt_mm_msg; retval_ = 2; return false; } + if( !ignore_trailing ) + { error_ = trailing_msg; retval_ = 2; return false; } + } pos = ipos + i - member_size; member_vector.push_back( Member( 0, trailer.data_size(), pos, member_size, dictionary_size ) ); return true; } if( ipos <= 0 ) - { set_num_error( "Member size in trailer is corrupt at pos ", pos - 8 ); + { if( ignore_gaps && !member_vector.empty() ) { pos = 0; return true; } + set_num_error( "Bad trailer at pos ", pos - Lzip_trailer::size ); return false; } bsize = buffer_size; - search_size = bsize - File_header::size; + search_size = bsize - Lzip_header::size; rd_size = block_size; ipos -= rd_size; std::memcpy( buffer + rd_size, buffer, buffer_size - rd_size ); @@ -117,20 +141,21 @@ bool File_index::skip_trailing_data( const int fd, long long & pos, } -File_index::File_index( const int infd, const bool ignore_bad_ds, - const bool ignore_trailing, const bool loose_trailing ) - : isize( lseek( infd, 0, SEEK_END ) ), retval_( 0 ) +Lzip_index::Lzip_index( const int infd, const bool ignore_trailing, + const bool loose_trailing, const bool ignore_bad_ds, + const bool ignore_gaps, const long long max_pos ) + : insize( lseek( infd, 0, SEEK_END ) ), retval_( 0 ) { - if( isize < 0 ) + if( insize < 0 ) { set_errno_error( "Input file is not seekable: " ); return; } - if( isize < min_member_size ) + if( insize < min_member_size ) { error_ = "Input file is too short."; retval_ = 2; return; } - if( isize > INT64_MAX ) + if( insize > INT64_MAX ) { error_ = "Input file is too long (2^63 bytes or more)."; retval_ = 2; return; } - File_header header; - if( seek_read( infd, header.data, File_header::size, 0 ) != File_header::size ) + Lzip_header header; + if( seek_read( infd, header.data, Lzip_header::size, 0 ) != Lzip_header::size ) { set_errno_error( "Error reading member header: " ); return; } if( !header.verify_magic() ) { error_ = bad_magic_msg; retval_ = 2; return; } @@ -139,32 +164,33 @@ File_index::File_index( const int infd, const bool ignore_bad_ds, if( !ignore_bad_ds && !isvalid_ds( header.dictionary_size() ) ) { error_ = bad_dict_msg; retval_ = 2; return; } - long long pos = isize; // always points to a header or to EOF + // pos always points to a header or to ( EOF || max_pos ) + long long pos = ( max_pos > 0 ) ? max_pos : insize; while( pos >= min_member_size ) { - File_trailer trailer; - if( seek_read( infd, trailer.data, File_trailer::size, - pos - File_trailer::size ) != File_trailer::size ) + Lzip_trailer trailer; + if( seek_read( infd, trailer.data, Lzip_trailer::size, + pos - Lzip_trailer::size ) != Lzip_trailer::size ) { set_errno_error( "Error reading member trailer: " ); break; } const unsigned long long member_size = trailer.member_size(); - if( member_size < min_member_size || member_size > (unsigned long long)pos ) + if( member_size > (unsigned long long)pos || !trailer.verify_consistency() ) { - if( member_vector.empty() ) - { if( skip_trailing_data( infd, pos, ignore_bad_ds, ignore_trailing, - loose_trailing ) ) continue; else return; } - set_num_error( "Member size in trailer is corrupt at pos ", pos - 8 ); + if( ignore_gaps || member_vector.empty() ) + { if( skip_gap( infd, pos, ignore_trailing, loose_trailing, + ignore_bad_ds, ignore_gaps ) ) continue; else return; } + set_num_error( "Bad trailer at pos ", pos - Lzip_trailer::size ); break; } - if( seek_read( infd, header.data, File_header::size, - pos - member_size ) != File_header::size ) + if( seek_read( infd, header.data, Lzip_header::size, + pos - member_size ) != Lzip_header::size ) { set_errno_error( "Error reading member header: " ); break; } const unsigned dictionary_size = header.dictionary_size(); if( !header.verify_magic() || !header.verify_version() || ( !ignore_bad_ds && !isvalid_ds( dictionary_size ) ) ) { - if( member_vector.empty() ) - { if( skip_trailing_data( infd, pos, ignore_bad_ds, ignore_trailing, - loose_trailing ) ) continue; else return; } + if( ignore_gaps || member_vector.empty() ) + { if( skip_gap( infd, pos, ignore_trailing, loose_trailing, + ignore_bad_ds, ignore_gaps ) ) continue; else return; } set_num_error( "Bad header at pos ", pos - member_size ); break; } @@ -172,14 +198,15 @@ File_index::File_index( const int infd, const bool ignore_bad_ds, member_vector.push_back( Member( 0, trailer.data_size(), pos, member_size, dictionary_size ) ); } - if( pos != 0 || member_vector.empty() ) + if( pos < 0 || pos >= min_member_size || ( pos != 0 && !ignore_gaps ) || + member_vector.empty() ) { 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 < member_vector.size() - 1; ++i ) + for( unsigned long i = 0; ; ++i ) { const long long end = member_vector[i].dblock.end(); if( end < 0 || end > INT64_MAX ) @@ -188,56 +215,57 @@ File_index::File_index( const int infd, const bool ignore_bad_ds, 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 ); } } // All files in 'infd_vector' must be at least 'fsize' bytes long. -File_index::File_index( const std::vector< int > & infd_vector, +Lzip_index::Lzip_index( const std::vector< int > & infd_vector, const long long fsize ) - : isize( fsize ), retval_( 0 ) + : insize( fsize ), retval_( 0 ) { - if( isize < 0 ) + if( insize < 0 ) { set_errno_error( "Input file is not seekable: " ); return; } - if( isize < min_member_size ) + if( insize < min_member_size ) { error_ = "Input file is too short."; retval_ = 2; return; } - if( isize > INT64_MAX ) + if( insize > INT64_MAX ) { error_ = "Input file is too long (2^63 bytes or more)."; retval_ = 2; return; } const int files = infd_vector.size(); - File_header header; + Lzip_header header; bool done = false; for( int i = 0; i < files && !done; ++i ) { const int infd = infd_vector[i]; - if( seek_read( infd, header.data, File_header::size, 0 ) != File_header::size ) + if( seek_read( infd, header.data, Lzip_header::size, 0 ) != Lzip_header::size ) { set_errno_error( "Error reading member header: " ); return; } if( header.verify_magic() && header.verify_version() ) done = true; } if( !done ) { error_ = bad_magic_msg; retval_ = 2; return; } - long long pos = isize; // always points to a header or to EOF + long long pos = insize; // always points to a header or to EOF while( pos >= min_member_size ) { unsigned long long member_size; - File_trailer trailer; + Lzip_trailer trailer; done = false; for( int it = 0; it < files && !done; ++it ) { const int tfd = infd_vector[it]; - if( seek_read( tfd, trailer.data, File_trailer::size, - pos - File_trailer::size ) != File_trailer::size ) + if( seek_read( tfd, trailer.data, Lzip_trailer::size, + pos - Lzip_trailer::size ) != Lzip_trailer::size ) { set_errno_error( "Error reading member trailer: " ); goto error; } member_size = trailer.member_size(); - if( member_size >= min_member_size && member_size <= (unsigned long long)pos ) + if( member_size <= (unsigned long long)pos && trailer.verify_consistency() ) for( int ih = 0; ih < files && !done; ++ih ) { const int hfd = infd_vector[ih]; - if( seek_read( hfd, header.data, File_header::size, - pos - member_size ) != File_header::size ) + if( seek_read( hfd, header.data, Lzip_header::size, + pos - member_size ) != Lzip_header::size ) { set_errno_error( "Error reading member header: " ); goto error; } if( header.verify_magic() && header.verify_version() ) done = true; } @@ -248,9 +276,9 @@ File_index::File_index( const std::vector< int > & infd_vector, set_num_error( "Member size in trailer may be corrupt at pos ", pos - 8 ); break; } - if( member_vector.empty() && isize > pos ) + if( member_vector.empty() && insize > pos ) { - const int size = std::min( (long long)File_header::size, isize - pos ); + const int size = std::min( (long long)Lzip_header::size, insize - pos ); for( int i = 0; i < files; ++i ) { const int infd = infd_vector[i]; @@ -274,7 +302,7 @@ error: return; } std::reverse( member_vector.begin(), member_vector.end() ); - for( unsigned long i = 0; i < member_vector.size() - 1; ++i ) + for( unsigned long i = 0; ; ++i ) { const long long end = member_vector[i].dblock.end(); if( end < 0 || end > INT64_MAX ) @@ -283,6 +311,18 @@ error: 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 ); } } + + +// Returns members + gaps [+ trailing data]. +long Lzip_index::blocks( const bool count_tdata ) const + { + long n = member_vector.size() + ( count_tdata && cdata_size() < file_size() ); + if( member_vector.size() && member_vector[0].mblock.pos() > 0 ) ++n; + for( unsigned long i = 1; i < member_vector.size(); ++i ) + if( member_vector[i].mblock.pos() > member_vector[i-1].mblock.end() ) ++n; + return n; + } |