Cabinet.dll Conformance Test

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Cabinet.dll Conformance Test

• Wine 3
• Aleksandr Liber
• Rizwan Kassim

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Purpose of the test

• Check for functional equivalence of Microsoft and
  WINE implementations
• Not really focusing on finding bugs, but in
  verifying that the WINE version outputs exactly
  what the Microsoft version does

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What is a Cabinet?

• Microsoft archive format
• Used in the Windows installation, Microsoft
  installers, and ActiveX component downloads
• Large Cab files can be split into groups of
  smaller ones and then combined back together

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Cabinet File Format

• Each file is stored in a folder. A folder can
  have many files.
• Files are compressed as a single unit for
  improved compression ratios
• Random Access speed however is adversely
  affected.
• Cabinet currently supports MSZip and LXW
  compression

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Cabinet API

• FCI (File Compression Interface)
• FCICreate - Create an FCI context.
• FCIAddFile - Add a file to the cabinet being
  created.
• FCIFlushCabinet - Complete the cabinet.
• FCIFlushFolder - Complete the folder and begin a
  new one.
• FCIDestroy - Destroy the FCI context.

• FDI (File Decompression Interface
• FDICreate - Create an FDI context.
• FDIIsCabinet Check whether or not a file is a
  cabinet, if it is the function returns
  information about it.
• FDICopy - Extract files from the cabinet.
• FDIDestroy Destroy the FDI context.

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Callback Functions

• The API makes extensive use of callback functions
• Most are for memory management and file I/O.
• Others Notify, Decrypt

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Cabinet API in WINE

• FCI not implemented since the majority of
  operations are done with extraction
• FDI appears to be fully implemented.
• So our decision was to focus on FDI

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Patch Description
Wine cabinet.dll FDI Conformance Test PatchRaw
files available at http//www.geekymedia.com/vie
wcvs/cgi/viewcvs.cgi/group3/wine/This patch
adds tests for the cabinet dll, specifically
testing thefunctions FDICreate, FDIDestroy,
FDICopy and FDIIsCabinet. As theFCI functions
are still marked FIXME in wine, they haven't
been tested.The package is self containing,
allowing additional cabinetfeatures to be tested
by preparing other cabinets in the same
mannerthat ours were.  A patch of -p1 will be
needed.This patch has been successfully applied
to the wine tree and ran.
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Files Included

• Modified Makefile.in(s) and configure.ac
• cabinet_fdi.c - the actual code of the test for
  FDI
• data.h - cabinet files and files used to make
  then stored in hex using C arrays
• genfiles.sh - shell script that can recreate
  data.h, useful for expansions to the test
• tvfs.h - Our virtual file system interface
• tvfs.c - Implementation of the above
• chexify.pl - Perl script that does the actual
  translation of a binary file to an array of
  hexadecimal values and creates C code out of it.

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Running of the Test

• TestCreate()
• Tests creation of an FDI context
• Just uses allocation functions
• TestInfo()
• Creates simple.cab, opens and reads it. Checks
  CABINFO struct. Repeat for complex.cab
• TestCopy()
• Creates simple.cab, open, reads it. Enumerates
  files in cabinet and prints list. Extracts all
  files in cabinet to virtual file system and
  byte-compares them with reference. Repeat for
  complex.
• TestDestroy()
• Destroys FDI context
• Only fails if its pointed to a non context

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Compilation Options

• To build outside Wine tree, compile with cl
  -DSTANDALONE -D_X86_ tvfs.c cabinet_fdi.c FDI.lib
• For verbose output in the test, compile with
  -DVERBOSE
• To enable debugging output in the virtual file
  system use -DTVFS_DEBUG

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Virtual File System

• TVFS-trivial virtual file system
• Provides virtual versions of the file system
  calls needed by FDI open, read, write, lseek,
  close.
• Each returns the same return values as the
  corresponding _open, _read, _write, _lseek,
  _close calls in Win32
• Functions for creating whole files from binary
  arrays, and comparing whole files to binary
  arrays as a testing aid
• Allows debugging insertion of various errors,
  Disk Full Access Denied CRC Error

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Virtual File System Structure

• Two arrays of structs, files and handlers
• tvfs_create creates a file with a specific
  name, size and content
• tvfs_open checks for existing file and assigns a
  handler
• tvfs_free performs bookkeeping, freeing
  dynamically associated memory.

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Cabinet File Generation

• data.h is generated using the genfiles shell
  script.
• This allow for easy addition of new cab files to
  the test.
• It uses cabarc.exe to create the cabinet files,
  and then uses chexify.pl to convert the file into
  a hexadecimal C array

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Snippets of genfiles.sh

• set -ex
• test -f cabsdk.exe wget -c http//download.micr
  osoft.com/download/platformsdk/cab/2.0/w98nt42kmex
  p/en-us/cabsdk.exe
• mkdir cabsdk cd cabsdk
• unzip ../cabsdk.exe cd ..
• chmod 744 cabsdk/BIN/CABARC.EXE
• Simple archive, just one 42 byte file
• echo gt simple.txt
• wine cabsdk/BIN/CABARC.EXE N simple.cab
  simple.txt
• More complicated archive, with two files
• cp ../../../README README
• cp ../../../COPYING.LIB lgpl.txt
• wine cabsdk/BIN/CABARC.EXE N complex.cab README
  lgpl.txt
• Pack source files and archives into hex arrays
• perl ../../../tools/chexify.pl simple.txt README
  lgpl.txt simple.cab complex.cab gt data.h

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Sample data.h

• const static char name_simple_txt
  "simple.txt"
• const static char file_simple_txt 0x53,
  0x6f, 0x20, 0x6c, 0x6f, 0x6e, 0x67, 0x2c, 0x20,
  0x61, 0x6e, 0x64, 0x20, 0x74, 0x68, 0x61, 0x6e,
  0x6b, 0x73, 0x20, 0x66, 0x6f, 0x72, 0x20, 0x61,
  0x6c, 0x6c, 0x20, 0x74, 0x68, 0x65, 0x20, 0x66,
  0x69, 0x73, 0x68, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
  0x0a
• const static int size_simple_txt
  sizeof(file_simple_txt)
• 'So long, and thanks for all the fish.....'

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Current Tests

• Simple.cab contains a single text file whose
  contents are So long and thanks for all the
  fish.
• Complex.cab a larger cabinet consisting of two
  text files, the wine README and lgpl.txt.
  (Previous versions compressed A Midsummers
  Nights Dream)

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Further Plans

• Current patch size with complex.cab
• 300k. (Too big AJ)
• Data.h representation bloats filesize x5
• Implement programmatic series to generate data
• Rand() with given srand
• Fibonacci series 255
• Use this data as the raw uncompressed data
• Data.h will just contain the compressed cabinet
• Add features to tvfs
• Disk full, etc notifications via ENOENT.
• Directory structure?

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Further Information

• Wiki www.geekymedia.com/twiki/bin/view.cgi/WineDev
  /Group3
• CVS www.geekymedia.com/viewcvs/cgi/viewcvs.cgi/gro
  up3/wine/