Merging upstream version 1.19.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 97 insertions, 38 deletions

diff --git a/file_index.cc b/file_index.cc
index 747c376..f2f81e7 100644
--- a/file_index.cc
+++ b/file_index.cc
@@ -1,5 +1,5 @@
 /*  Lziprecover - Data recovery tool for the lzip format
-    Copyright (C) 2009-2016 Antonio Diaz Diaz.
+    Copyright (C) 2009-2017 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
@@ -15,6 +15,8 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#define _FILE_OFFSET_BITS 64
+
 #include <algorithm>
 #include <cerrno>
 #include <cstdio>
@@ -44,17 +46,75 @@ void File_index::set_errno_error( const char * const msg )
   retval_ = 1;
   }
 
-void File_index::set_num_error( const char * const msg1, unsigned long long num,
-                                const char * const msg2 )
+void File_index::set_num_error( const char * const msg, unsigned long long num )
   {
   char buf[80];
-  snprintf( buf, sizeof buf, "%s%llu%s", msg1, num, msg2 );
+  snprintf( buf, sizeof buf, "%s%llu", msg, num );
   error_ = buf;
   retval_ = 2;
   }
 
 
-File_index::File_index( const int infd )
+// If successful, push last member and set pos to member header.
+bool File_index::skip_trailing_data( const int fd, const bool ignore_bad_ds,
+                                     long long & pos )
+  {
+  enum { block_size = 16384,
+         buffer_size = block_size + File_trailer::size - 1 + File_header::size };
+  uint8_t buffer[buffer_size];
+  if( pos < min_member_size ) 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
+  int rd_size = bsize;				// bytes to read from file
+  unsigned long long ipos = pos - rd_size;	// aligned to block_size
+
+  while( true )
+    {
+    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 )
+      if( buffer[i-1] <= max_msb )	// most significant byte of member_size
+        {
+        File_trailer & trailer =
+          *(File_trailer *)( buffer + i - File_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 )
+          continue;
+        File_header header;
+        if( seek_read( fd, header.data, File_header::size,
+                       ipos + i - member_size ) != File_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;
+          }
+        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 );
+        return false; }
+    bsize = buffer_size;
+    search_size = bsize - File_header::size;
+    rd_size = block_size;
+    ipos -= rd_size;
+    std::memcpy( buffer + rd_size, buffer, buffer_size - rd_size );
+    }
+  }
+
+
+File_index::File_index( const int infd, const bool ignore_bad_ds,
+                        const bool ignore_trailing )
   : isize( lseek( infd, 0, SEEK_END ) ), retval_( 0 )
   {
   if( isize < 0 )
@@ -69,48 +129,46 @@ File_index::File_index( const int infd )
   if( seek_read( infd, header.data, File_header::size, 0 ) != File_header::size )
     { set_errno_error( "Error reading member header: " ); return; }
   if( !header.verify_magic() )
-    { error_ = "Bad magic number (file not in lzip format).";
-      retval_ = 2; return; }
+    { error_ = bad_magic_msg; retval_ = 2; return; }
   if( !header.verify_version() )
-    { set_num_error( "Version ", header.version(),
-                     " member format not supported." ); return; }
+    { error_ = bad_version( header.version() ); retval_ = 2; return; }
+  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
+  long long pos = isize;	// always points to a header or to EOF
   while( pos >= min_member_size )
     {
     File_trailer trailer;
     if( seek_read( infd, trailer.data, File_trailer::size,
                    pos - File_trailer::size ) != File_trailer::size )
       { set_errno_error( "Error reading member trailer: " ); break; }
-    const long long member_size = trailer.member_size();
-    if( member_size < min_member_size || member_size > pos )
+    const unsigned long long member_size = trailer.member_size();
+    if( member_size < min_member_size || member_size > (unsigned long long)pos )
       {
-      if( member_vector.empty() )
-        { --pos; continue; }			// maybe trailing data
-      set_num_error( "Member size in trailer is corrupt at pos ", pos - 8 );
+      if( !member_vector.empty() )
+        set_num_error( "Member size in trailer is corrupt at pos ", pos - 8 );
+      else if( skip_trailing_data( infd, ignore_bad_ds, pos ) )
+        { if( ignore_trailing ) continue;
+          error_ = trailing_msg; retval_ = 2; return; }
       break;
       }
     if( seek_read( infd, header.data, File_header::size,
                    pos - member_size ) != File_header::size )
       { set_errno_error( "Error reading member header: " ); break; }
-    if( !header.verify_magic() || !header.verify_version() )
-      {
-      if( member_vector.empty() )
-        { --pos; continue; }			// maybe trailing data
-      set_num_error( "Bad header at pos ", pos - member_size );
-      break;
-      }
     const unsigned dictionary_size = header.dictionary_size();
-    if( member_vector.empty() && isize - pos > File_header::size &&
-        seek_read( infd, header.data, File_header::size, pos ) == File_header::size &&
-        header.verify_magic() && header.verify_version() )
+    if( !header.verify_magic() || !header.verify_version() ||
+        ( !ignore_bad_ds && !isvalid_ds( dictionary_size ) ) )
       {
-      error_ = "Last member in input file is truncated or corrupt.";
-      retval_ = 2; break;
+      if( !member_vector.empty() )
+        set_num_error( "Bad header at pos ", pos - member_size );
+      else if( skip_trailing_data( infd, ignore_bad_ds, pos ) )
+        { if( ignore_trailing ) continue;
+          error_ = trailing_msg; retval_ = 2; return; }
+      break;
       }
     pos -= member_size;
-    member_vector.push_back( Member( 0, trailer.data_size(),
-                                     pos, member_size, dictionary_size ) );
+    member_vector.push_back( Member( 0, trailer.data_size(), pos,
+                                     member_size, dictionary_size ) );
     }
   if( pos != 0 || member_vector.empty() )
     {
@@ -157,13 +215,12 @@ File_index::File_index( const std::vector< int > & infd_vector,
     if( header.verify_magic() && header.verify_version() ) done = true;
     }
   if( !done )
-    { error_ = "Bad magic number (file not in lzip format).";
-      retval_ = 2; return; }
+    { error_ = bad_magic_msg; retval_ = 2; return; }
 
   long long pos = isize;		// always points to a header or to EOF
   while( pos >= min_member_size )
     {
-    long long member_size;
+    unsigned long long member_size;
     File_trailer trailer;
     done = false;
     for( int it = 0; it < files && !done; ++it )
@@ -173,7 +230,7 @@ File_index::File_index( const std::vector< int > & infd_vector,
                      pos - File_trailer::size ) != File_trailer::size )
         { set_errno_error( "Error reading member trailer: " ); goto error; }
       member_size = trailer.member_size();
-      if( member_size >= min_member_size && member_size <= pos )
+      if( member_size >= min_member_size && member_size <= (unsigned long long)pos )
         for( int ih = 0; ih < files && !done; ++ih )
           {
           const int hfd = infd_vector[ih];
@@ -185,22 +242,24 @@ File_index::File_index( const std::vector< int > & infd_vector,
       }
     if( !done )
       {
-      if( member_vector.empty() )		// maybe trailing data
-        { --pos; continue; }
+      if( member_vector.empty() ) { --pos; continue; }	// maybe trailing data
       set_num_error( "Member size in trailer may be corrupt at pos ", pos - 8 );
       break;
       }
-    if( member_vector.empty() && isize - pos > File_header::size )
+    if( member_vector.empty() && isize > pos )
+      {
+      const int size = std::min( (long long)File_header::size, isize - pos );
       for( int i = 0; i < files; ++i )
         {
         const int infd = infd_vector[i];
-        if( seek_read( infd, header.data, File_header::size, pos ) == File_header::size &&
-            header.verify_magic() && header.verify_version() )
+        if( seek_read( infd, header.data, size, pos ) == size &&
+            header.verify_prefix( size ) )
           {
           error_ = "Last member in input file is truncated or corrupt.";
           retval_ = 2; goto error;
           }
         }
+      }
     pos -= member_size;
     member_vector.push_back( Member( 0, trailer.data_size(),
                                      pos, member_size, 0 ) );