1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#include "scdetect.hxx"

#include <sal/macros.h>

#include <com/sun/star/lang/XMultiServiceFactory.hpp>
#include <com/sun/star/beans/PropertyValue.hpp>
#include <com/sun/star/uno/XComponentContext.hpp>
#include <cppuhelper/supportsservice.hxx>
#include <com/sun/star/container/XNameAccess.hpp>
#include <com/sun/star/io/XInputStream.hpp>
#include <unotools/mediadescriptor.hxx>
#include <sfx2/docfile.hxx>
#include <sfx2/docfilt.hxx>
#include <sfx2/fcontnr.hxx>
#include <tools/solar.h>

using namespace ::com::sun::star;
using utl::MediaDescriptor;

namespace {

// table with search pattern
// meaning of the sequences
// 0x00??: the exact byte 0x?? must be at that place
// 0x0100: read over a byte (don't care)
// 0x02nn: a byte of 0xnn variations follows
// 0x8000: recognition finished

#define M_DC        0x0100
#define M_ALT(CNT)  (0x0200+(CNT))
#define M_ENDE      0x8000

const sal_uInt16 pLotus[] =      // Lotus 1/1A/2
    { 0x0000, 0x0000, 0x0002, 0x0000,
    M_ALT(2), 0x0004, 0x0006,
    0x0004, M_ENDE };

const sal_uInt16 pLotusNew[] =   // Lotus >= 9.7
    { 0x0000, 0x0000, M_DC, 0x0000,     // Rec# + Len (0x1a)
      M_ALT(3), 0x0003, 0x0004, 0x0005, // File Revision Code 97->ME
      0x0010, 0x0004, 0x0000, 0x0000,
      M_ENDE };

const sal_uInt16 pLotus2[] =     // Lotus >3
    { 0x0000, 0x0000, 0x001A, 0x0000,   // Rec# + Len (26)
    M_ALT(2), 0x0000, 0x0002,         // File Revision Code
    0x0010,
    0x0004, 0x0000,                   // File Revision Subcode
    M_ENDE };

const sal_uInt16 pQPro[] =
       { 0x0000, 0x0000, 0x0002, 0x0000,
         M_ALT(4), 0x0001, 0x0002, // WB1, WB2
         0x0006, 0x0007,           // QPro 6/7 (?)
         0x0010,
         M_ENDE };

const sal_uInt16 pDIF1[] =       // DIF with CR-LF
    {
    'T', 'A', 'B', 'L', 'E',
    M_DC, M_DC,
    '0', ',', '1',
    M_DC, M_DC,
    '\"',
    M_ENDE };

const sal_uInt16 pDIF2[] =       // DIF with CR or LF
    {
    'T', 'A', 'B', 'L', 'E',
    M_DC,
    '0', ',', '1',
    M_DC,
    '\"',
    M_ENDE };

const sal_uInt16 pSylk[] =       // Sylk
    {
    'I', 'D', ';',
    M_ALT(3), 'P', 'N', 'E',        // 'P' plus undocumented Excel extensions 'N' and 'E'
    M_ENDE };

bool detectThisFormat(SvStream& rStr, const sal_uInt16* pSearch)
{
    sal_uInt8 nByte;
    rStr.Seek( 0 ); // in the beginning everything was bad...
    rStr.ReadUChar( nByte );
    bool bSync = true;
    while( !rStr.eof() && bSync )
    {
        sal_uInt16 nMuster = *pSearch;

        if( nMuster < 0x0100 )
        { // compare bytes
            if( static_cast<sal_uInt8>(nMuster) != nByte )
                bSync = false;
        }
        else if( nMuster & M_DC )
        { // don't care
        }
        else if( nMuster & M_ALT(0) )
        { // alternative Bytes
            sal_uInt8 nCntAlt = static_cast<sal_uInt8>(nMuster);
            bSync = false;          // first unsynchron
            while( nCntAlt > 0 )
            {
                pSearch++;
                if( static_cast<sal_uInt8>(*pSearch) == nByte )
                    bSync = true;   // only now synchronization
                nCntAlt--;
            }
        }
        else if( nMuster & M_ENDE )
        { // Format detected
            return true;
        }

        pSearch++;
        rStr.ReadUChar( nByte );
    }

    return false;
}

}

ScFilterDetect::ScFilterDetect()
{
}

ScFilterDetect::~ScFilterDetect()
{
}

#if 0
// This method is no longer used, but I do want to keep this for now to see
// if we could transfer this check to the now centralized ascii detection
// code in the filter module.
static sal_Bool lcl_MayBeAscii( SvStream& rStream )
{
    // ASCII/CSV is considered possible if there are no null bytes, or a Byte
    // Order Mark is present, or if, for Unicode UCS2/UTF-16, all null bytes
    // are on either even or uneven byte positions.

    rStream.Seek(STREAM_SEEK_TO_BEGIN);

    const size_t nBufSize = 2048;
    sal_uInt16 aBuffer[ nBufSize ];
    sal_uInt8* pByte = reinterpret_cast<sal_uInt8*>(aBuffer);
    sal_uLong nBytesRead = rStream.Read( pByte, nBufSize*2);

    if ( nBytesRead >= 2 && (aBuffer[0] == 0xfffe || aBuffer[0] == 0xfeff) )
    {
        // Unicode BOM file may contain null bytes.
        return sal_True;
    }

    const sal_uInt16* p = aBuffer;
    sal_uInt16 nMask = 0xffff;
    nBytesRead /= 2;
    while( nBytesRead-- && nMask )
    {
        sal_uInt16 nVal = *p++ & nMask;
        if (!(nVal & 0x00ff))
            nMask &= 0xff00;
        if (!(nVal & 0xff00))
            nMask &= 0x00ff;
    }

    return nMask != 0;
}
#endif

static bool lcl_MayBeDBase( SvStream& rStream )
{
    // Look for dbf marker, see connectivity/source/inc/dbase/DTable.hxx
    // DBFType for values.
    const sal_uInt8 nValidMarks[] = {
        0x03, 0x04, 0x05, 0x30, 0x31, 0x43, 0xB3, 0x83, 0x8b, 0x8e, 0xf5 };
    sal_uInt8 nMark;
    rStream.Seek(STREAM_SEEK_TO_BEGIN);
    rStream.ReadUChar( nMark );
    bool bValidMark = false;
    for (size_t i=0; i < SAL_N_ELEMENTS(nValidMarks) && !bValidMark; ++i)
    {
        if (nValidMarks[i] == nMark)
            bValidMark = true;
    }
    if ( !bValidMark )
        return false;

    const size_t nHeaderBlockSize = 32;
    // Empty dbf is >= 32*2+1 bytes in size.
    const size_t nEmptyDbf = nHeaderBlockSize * 2 + 1;

    sal_uLong nSize = rStream.TellEnd();
    if ( nSize < nEmptyDbf )
        return false;

    // count of records at 4
    rStream.Seek(4);
    sal_uInt32 nRecords(0);
    rStream.ReadUInt32(nRecords);

    // length of header starts at 8
    rStream.Seek(8);
    sal_uInt16 nHeaderLen;
    rStream.ReadUInt16( nHeaderLen );

    // size of record at 10
    sal_uInt16 nRecordSize(0);
    rStream.ReadUInt16(nRecordSize);

    if ( nHeaderLen < nEmptyDbf || nSize < nHeaderLen )
        return false;

    // see DTable.cxx ODbaseTable::readHeader()
    if (0 == nRecordSize)
        return false;

    // see DTable.cxx ODbaseTable::construct() line 546
    if (0 == nRecords)
    {
        nRecords = (nSize - nHeaderLen) / nRecordSize;
    }

    // tdf#84834 sanity check of size
    // tdf#106423: a dbf file can have 0 record, so no need to check nRecords
    if (nSize < nHeaderLen + nRecords * sal_uInt64(nRecordSize))
        return false;

    // Last byte of header must be 0x0d, this is how it's specified.
    // #i9581#,#i26407# but some applications don't follow the specification
    // and pad the header with one byte 0x00 to reach an
    // even boundary. Some (#i88577# ) even pad more or pad using a 0x1a ^Z
    // control character (#i8857#). This results in:
    // Last byte of header must be 0x0d on 32 bytes boundary.
    sal_uInt16 nBlocks = (nHeaderLen - 1) / nHeaderBlockSize;
    sal_uInt8 nEndFlag = 0;
    while ( nBlocks > 1 && nEndFlag != 0x0d ) {
        rStream.Seek( nBlocks-- * nHeaderBlockSize );
        rStream.ReadUChar( nEndFlag );
    }

    return ( 0x0d == nEndFlag );
}

OUString SAL_CALL ScFilterDetect::detect( uno::Sequence<beans::PropertyValue>& lDescriptor )
{
    MediaDescriptor aMediaDesc( lDescriptor );
    OUString aTypeName = aMediaDesc.getUnpackedValueOrDefault( MediaDescriptor::PROP_TYPENAME(), OUString() );
    uno::Reference< io::XInputStream > xStream ( aMediaDesc[MediaDescriptor::PROP_INPUTSTREAM()], uno::UNO_QUERY );
    if ( !xStream.is() )
        return OUString();

    SfxMedium aMedium;
    aMedium.UseInteractionHandler( false );
    aMedium.setStreamToLoadFrom( xStream, true );

    SvStream* pStream = aMedium.GetInStream();
    if ( !pStream || pStream->GetError() )
        // No stream, no detection.
        return OUString();

    const char* pSearchFilterName = nullptr;
    if (aTypeName == "calc_Lotus")
    {
        if (!detectThisFormat(*pStream, pLotus) && !detectThisFormat(*pStream, pLotusNew) && !detectThisFormat(*pStream, pLotus2))
            return OUString();

        pSearchFilterName = "Lotus";
    }
    else if (aTypeName == "calc_QPro")
    {
        if (!detectThisFormat(*pStream, pQPro))
            return OUString();

        pSearchFilterName = "Quattro Pro 6.0";
    }
    else if (aTypeName == "calc_SYLK")
    {
        if (!detectThisFormat(*pStream, pSylk))
            return OUString();

        pSearchFilterName = "SYLK";
    }
    else if (aTypeName == "calc_DIF")
    {
        if (!detectThisFormat(*pStream, pDIF1) && !detectThisFormat(*pStream, pDIF2))
            return OUString();

        pSearchFilterName = "DIF";
    }
    else if (aTypeName == "calc_dBase")
    {
        if (!lcl_MayBeDBase(*pStream))
            return OUString();

        pSearchFilterName = "dBase";
    }
    else
        return OUString();

    SfxFilterMatcher aMatcher("scalc");
    std::shared_ptr<const SfxFilter> pFilter = aMatcher.GetFilter4FilterName(OUString::createFromAscii(pSearchFilterName));

    if (!pFilter)
        return OUString();

    aMediaDesc[MediaDescriptor::PROP_FILTERNAME()] <<= pFilter->GetName();
    aMediaDesc >> lDescriptor;
    return aTypeName;
}

OUString SAL_CALL ScFilterDetect::getImplementationName()
{
    return OUString("com.sun.star.comp.calc.FormatDetector");
}

sal_Bool ScFilterDetect::supportsService( const OUString& sServiceName )
{
    return cppu::supportsService(this, sServiceName);
}

css::uno::Sequence<OUString> ScFilterDetect::getSupportedServiceNames()
{
    uno::Sequence<OUString> seqServiceNames { "com.sun.star.frame.ExtendedTypeDetection" };
    return seqServiceNames;
}

extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface*
com_sun_star_comp_calc_FormatDetector_get_implementation(css::uno::XComponentContext* /*context*/,<--- The function 'com_sun_star_comp_calc_FormatDetector_get_implementation' is never used.
                                                         css::uno::Sequence<css::uno::Any> const &)
{
    return cppu::acquire(new ScFilterDetect);
}


/* vim:set shiftwidth=4 softtabstop=4 expandtab: */