This repository has been archived by the owner on Jan 23, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 2.7k
/
nativeformatreader.h
726 lines (626 loc) · 21.3 KB
/
nativeformatreader.h
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
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
// ---------------------------------------------------------------------------
// NativeFormatReader
//
// Utilities to read native data from images
// ---------------------------------------------------------------------------
#pragma once
#ifndef DACCESS_COMPILE
#if defined(_AMD64_) || defined(_X86_)
#include "emmintrin.h"
#define USE_INTEL_INTRINSICS_FOR_CUCKOO_FILTER
#elif defined(_ARM_) || defined(_ARM64_)
#ifndef FEATURE_PAL // The Mac and Linux build environments are not setup for NEON simd.
#define USE_ARM_INTRINSICS_FOR_CUCKOO_FILTER
#if defined(_ARM_)
#include "arm_neon.h"
#else
#include "arm64_neon.h"
#endif
#endif // FEATURE_PAL
#endif // _ARM_ || _ARM64_
#endif // DACCESS_COMPILE
// To reduce differences between C# and C++ versions
#define byte uint8_t
#define uint uint32_t
#define UInt16 uint16_t
#define UInt32 uint32_t
#define UInt64 uint64_t
namespace NativeFormat
{
class NativeReader;
class NativeHashtable;
typedef DPTR(NativeReader) PTR_NativeReader;
typedef DPTR(NativeHashtable) PTR_NativeHashtable;
class NativeReader
{
PTR_BYTE _base;
uint _size;
public:
NativeReader()
{
_base = NULL;
_size = 0;
}
NativeReader(PTR_BYTE base_, uint size)
{
_base = base_;
_size = size;
}
void ThrowBadImageFormatException()
{
_ASSERTE(false);
#if !defined(DACCESS_COMPILE) && !defined(CROSSGEN_COMPILE)
// Failfast instead of throwing, to avoid violating NOTHROW contracts of callers
EEPOLICY_HANDLE_FATAL_ERROR(COR_E_BADIMAGEFORMAT);
#endif
}
uint EnsureOffsetInRange(uint offset, uint lookAhead)
{
if ((int)offset < 0 || offset + lookAhead >= _size)
ThrowBadImageFormatException();
return offset;
}
byte ReadUInt8(uint offset)
{
if (offset >= _size)
ThrowBadImageFormatException();
return *(_base + offset); // Assumes little endian and unaligned access
}
UInt16 ReadUInt16(uint offset)
{
if ((int)offset < 0 || offset + 1 >= _size)
ThrowBadImageFormatException();
return *dac_cast<PTR_USHORT>(_base + offset); // Assumes little endian and unaligned access
}
UInt32 ReadUInt32(uint offset)
{
if ((int)offset < 0 || offset + 3 >= _size)
ThrowBadImageFormatException();
return *dac_cast<PTR_UINT32>(_base + offset); // Assumes little endian and unaligned access
}
uint DecodeUnsigned(uint offset, uint * pValue)
{
if (offset >= _size)
ThrowBadImageFormatException();
uint val = *(_base + offset);
if ((val & 1) == 0)
{
*pValue = (val >> 1);
offset += 1;
}
else
if ((val & 2) == 0)
{
if (offset + 1 >= _size)
ThrowBadImageFormatException();
*pValue = (val >> 2) |
(((uint)*(_base + offset + 1)) << 6);
offset += 2;
}
else
if ((val & 4) == 0)
{
if (offset + 2 >= _size)
ThrowBadImageFormatException();
*pValue = (val >> 3) |
(((uint)*(_base + offset + 1)) << 5) |
(((uint)*(_base + offset + 2)) << 13);
offset += 3;
}
else
if ((val & 8) == 0)
{
if (offset + 3 >= _size)
ThrowBadImageFormatException();
*pValue = (val >> 4) |
(((uint)*(_base + offset + 1)) << 4) |
(((uint)*(_base + offset + 2)) << 12) |
(((uint)*(_base + offset + 3)) << 20);
offset += 4;
}
else
if ((val & 16) == 0)
{
*pValue = ReadUInt32(offset + 1);
offset += 5;
}
else
{
ThrowBadImageFormatException();
}
return offset;
}
int DecodeSigned(uint offset, int * pValue)
{
if (offset >= _size)
ThrowBadImageFormatException();
int val = *(_base + offset);
if ((val & 1) == 0)
{
*pValue = val >> 1;
offset += 1;
}
else if ((val & 2) == 0)
{
if (offset + 1 >= _size)
ThrowBadImageFormatException();
*pValue = (val >> 2) |
(((int)*(_base + offset + 1)) << 6);
offset += 2;
}
else if ((val & 4) == 0)
{
if (offset + 2 >= _size)
ThrowBadImageFormatException();
*pValue = (val >> 3) |
(((int)*(_base + offset + 1)) << 5) |
(((int)*(_base + offset + 2)) << 13);
offset += 3;
}
else if ((val & 8) == 0)
{
if (offset + 3 >= _size)
ThrowBadImageFormatException();
*pValue = (val >> 4) |
(((int)*(_base + offset + 1)) << 4) |
(((int)*(_base + offset + 2)) << 12) |
(((int)*(_base + offset + 3)) << 20);
offset += 4;
}
else if ((val & 16) == 0)
{
*pValue = (int)ReadUInt32(offset + 1);
offset += 5;
}
else
{
ThrowBadImageFormatException();
}
return offset;
}
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4702) // Disable unreachable code warning
#endif
uint SkipInteger(uint offset)
{
EnsureOffsetInRange(offset, 0);
PTR_BYTE data = (_base + offset);
if ((*data & 1) == 0)
{
return offset + 1;
}
else if ((*data & 2) == 0)
{
return offset + 2;
}
else if ((*data & 4) == 0)
{
return offset + 3;
}
else if ((*data & 8) == 0)
{
return offset + 4;
}
else if ((*data & 16) == 0)
{
return offset + 5;
}
else if ((*data & 32) == 0)
{
return offset + 9;
}
else
{
ThrowBadImageFormatException();
return offset;
}
}
#ifndef DACCESS_COMPILE
const BYTE* GetBlob(uint offset)
{
EnsureOffsetInRange(offset, 0);
return _base + offset;
}
#endif
#ifdef _MSC_VER
#pragma warning(pop)
#endif
};
class NativeParser
{
PTR_NativeReader _pReader;
uint _offset;
public:
NativeParser()
: _pReader(PTR_NULL), _offset(0)
{
}
NativeParser(PTR_NativeReader pReader, uint offset)
{
_pReader = pReader;
_offset = offset;
}
bool IsNull() { return _pReader == NULL; }
NativeReader * GetNativeReader() { return _pReader; }
uint GetOffset() { return _offset; }
void SetOffset(uint value) { _offset = value; }
void ThrowBadImageFormatException()
{
_pReader->ThrowBadImageFormatException();
}
byte GetUInt8()
{
byte val = _pReader->ReadUInt8(_offset);
_offset += 1;
return val;
}
uint GetUnsigned()
{
uint value;
_offset = _pReader->DecodeUnsigned(_offset, &value);
return value;
}
int GetSigned()
{
int value;
_offset = _pReader->DecodeSigned(_offset, &value);
return value;
}
uint GetRelativeOffset()
{
uint pos = _offset;
int delta;
_offset = _pReader->DecodeSigned(_offset, &delta);
return pos + (uint)delta;
}
#ifndef DACCESS_COMPILE
const BYTE * GetBlob()
{
return _pReader->GetBlob(_offset);
}
#endif
void SkipInteger()
{
_offset = _pReader->SkipInteger(_offset);
}
NativeParser GetParserFromRelativeOffset()
{
return NativeParser(_pReader, GetRelativeOffset());
}
};
class NativeArray
{
PTR_NativeReader _pReader;
uint _baseOffset;
uint _nElements;
byte _entryIndexSize;
static const uint _blockSize = 16;
public:
NativeArray()
: _pReader(PTR_NULL), _nElements(0)
{
}
NativeArray(PTR_NativeReader pReader, uint offset)
: _pReader(pReader)
{
uint val;
_baseOffset = pReader->DecodeUnsigned(offset, &val);
_nElements = (val >> 2);
_entryIndexSize = (val & 3);
}
uint GetCount()
{
return _nElements;
}
bool TryGetAt(uint index, uint * pOffset)
{
if (index >= _nElements)
return false;
uint offset;
if (_entryIndexSize == 0)
{
offset = _pReader->ReadUInt8(_baseOffset + (index / _blockSize));
}
else if (_entryIndexSize == 1)
{
offset = _pReader->ReadUInt16(_baseOffset + 2 * (index / _blockSize));
}
else
{
offset = _pReader->ReadUInt32(_baseOffset + 4 * (index / _blockSize));
}
offset += _baseOffset;
for (uint bit = _blockSize >> 1; bit > 0; bit >>= 1)
{
uint val;
uint offset2 = _pReader->DecodeUnsigned(offset, &val);
if (index & bit)
{
if ((val & 2) != 0)
{
offset = offset + (val >> 2);
continue;
}
}
else
{
if ((val & 1) != 0)
{
offset = offset2;
continue;
}
}
// Not found
if ((val & 3) == 0)
{
// Matching special leaf node?
if ((val >> 2) == (index & (_blockSize - 1)))
{
offset = offset2;
break;
}
}
return false;
}
*pOffset = offset;
return true;
}
};
class NativeHashtable
{
PTR_NativeReader _pReader;
uint _baseOffset;
uint _bucketMask;
byte _entryIndexSize;
NativeParser GetParserForBucket(uint bucket, uint * pEndOffset)
{
uint start, end;
if (_entryIndexSize == 0)
{
uint bucketOffset = _baseOffset + bucket;
start = _pReader->ReadUInt8(bucketOffset);
end = _pReader->ReadUInt8(bucketOffset + 1);
}
else if (_entryIndexSize == 1)
{
uint bucketOffset = _baseOffset + 2 * bucket;
start = _pReader->ReadUInt16(bucketOffset);
end = _pReader->ReadUInt16(bucketOffset + 2);
}
else
{
uint bucketOffset = _baseOffset + 4 * bucket;
start = _pReader->ReadUInt32(bucketOffset);
end = _pReader->ReadUInt32(bucketOffset + 4);
}
*pEndOffset = end + _baseOffset;
return NativeParser(_pReader, _baseOffset + start);
}
public:
NativeHashtable() : _pReader(PTR_NULL), _baseOffset(0), _bucketMask(0), _entryIndexSize(0)
{
}
NativeHashtable(NativeParser& parser)
{
uint header = parser.GetUInt8();
_pReader = dac_cast<PTR_NativeReader>(parser.GetNativeReader());
_baseOffset = parser.GetOffset();
int numberOfBucketsShift = (int)(header >> 2);
if (numberOfBucketsShift > 31)
_pReader->ThrowBadImageFormatException();
_bucketMask = (uint)((1 << numberOfBucketsShift) - 1);
byte entryIndexSize = (byte)(header & 3);
if (entryIndexSize > 2)
_pReader->ThrowBadImageFormatException();
_entryIndexSize = entryIndexSize;
}
bool IsNull() { return _pReader == NULL; }
class AllEntriesEnumerator
{
PTR_NativeHashtable _table;
NativeParser _parser;
uint _currentBucket;
uint _endOffset;
public:
AllEntriesEnumerator() :
_table(dac_cast<PTR_NativeHashtable>(nullptr)),
_parser(),
_currentBucket(0),
_endOffset(0)
{
}
AllEntriesEnumerator(PTR_NativeHashtable table)
{
_table = table;
_currentBucket = 0;
if (_table != NULL)
{
_parser = _table->GetParserForBucket(_currentBucket, &_endOffset);
}
}
NativeParser GetNext()
{
if (_table == NULL)
{
return NativeParser();
}
for (; ; )
{
if (_parser.GetOffset() < _endOffset)
{
// Skip hashcode to get to the offset
_parser.GetUInt8();
return _parser.GetParserFromRelativeOffset();
}
if (_currentBucket >= _table->_bucketMask)
{
return NativeParser();
}
_currentBucket++;
_parser = _table->GetParserForBucket(_currentBucket, &_endOffset);
}
}
};
//
// The enumerator does not conform to the regular C# enumerator pattern to avoid paying
// its performance penalty (allocation, multiple calls per iteration)
//
class Enumerator
{
NativeParser _parser;
uint _endOffset;
byte _lowHashcode;
public:
Enumerator(NativeParser parser, uint endOffset, byte lowHashcode)
{
_parser = parser;
_endOffset = endOffset;
_lowHashcode = lowHashcode;
}
bool GetNext(NativeParser& entryParser)
{
while (_parser.GetOffset() < _endOffset)
{
byte lowHashcode = _parser.GetUInt8();
if (lowHashcode == _lowHashcode)
{
entryParser = _parser.GetParserFromRelativeOffset();
return true;
}
// The entries are sorted by hashcode within the bucket. It allows us to terminate the lookup prematurely.
if (lowHashcode > _lowHashcode)
{
_endOffset = _parser.GetOffset(); // Ensure that extra call to GetNext returns null parser again
break;
}
_parser.SkipInteger();
}
return false;
}
};
// The recommended code pattern to perform lookup is:
//
// NativeHashtable::Enumerator lookup = hashtable.Lookup(dwHashCode);
// NativeParser entryParser;
// while (lookup.GetNext(entryParser))
// {
// ... read entry using entryParser ...
// }
//
Enumerator Lookup(int hashcode)
{
uint endOffset;
uint bucket = ((uint)hashcode >> 8) & _bucketMask;
NativeParser parser = GetParserForBucket(bucket, &endOffset);
return Enumerator(parser, endOffset, (byte)hashcode);
}
};
class NativeCuckooFilter;
typedef DPTR(NativeCuckooFilter) PTR_NativeCuckooFilter;
class NativeCuckooFilter
{
PTR_BYTE _base;
UInt32 _size;
LONG _disableFilter;
bool IsPowerOfTwo(UInt32 number)
{
return (number & (number - 1)) == 0;
}
public:
static UInt32 ComputeFingerprintHash(UInt16 fingerprint)
{
// As the number of buckets is not reasonably greater than 65536, just use fingerprint as its own hash
// This implies that the hash of the entrypoint should be an independent hash function as compared
// to the fingerprint
return fingerprint;
}
NativeCuckooFilter()
{
_base = NULL;
_size = 0;
_disableFilter = 0;
}
NativeCuckooFilter(PTR_BYTE base_, UInt32 size, UInt32 rvaOfTable, UInt32 filterSize)
{
if (((rvaOfTable & 0xF) != 0) || ((filterSize & 0xF) != 0))
{
// Native cuckoo filters must be aligned at 16byte boundaries within the PE file
NativeReader exceptionReader;
exceptionReader.ThrowBadImageFormatException();
}
if ((filterSize != 0) && !IsPowerOfTwo(filterSize))
{
// Native cuckoo filters must be power of two in size
NativeReader exceptionReader;
exceptionReader.ThrowBadImageFormatException();
}
_base = base_ + rvaOfTable;
_size = filterSize;
_disableFilter = 0;
}
void DisableFilter()
{
// Set disable filter flag using interlocked to ensure that future
// attempts to read the filter will capture the change.
InterlockedExchange(&_disableFilter, 1);
}
bool HashComputationImmaterial()
{
if ((_base == NULL) || (_size == 0))
return true;
return false;
}
bool MayExist(UInt32 hashcode, UInt16 fingerprint)
{
if ((_base == NULL) || (_disableFilter))
return true;
if (_size == 0)
return false; // Empty table means none of the attributes exist
// Fingerprints of 0 don't actually exist. Just use 1, and lose some entropy
if (fingerprint == 0)
fingerprint = 1;
UInt32 bucketCount = _size / 16;
UInt32 bucketMask = bucketCount - 1; // filters are power of 2 in size
UInt32 bucketAIndex = hashcode & bucketMask;
UInt32 bucketBIndex = bucketAIndex ^ (ComputeFingerprintHash(fingerprint) & bucketMask);
#if defined(USE_INTEL_INTRINSICS_FOR_CUCKOO_FILTER)
__m128i bucketA = _mm_loadu_si128(&((__m128i*)_base)[bucketAIndex]);
__m128i bucketB = _mm_loadu_si128(&((__m128i*)_base)[bucketBIndex]);
__m128i fingerprintSIMD = _mm_set1_epi16(fingerprint);
__m128i bucketACompare = _mm_cmpeq_epi16(bucketA, fingerprintSIMD);
__m128i bucketBCompare = _mm_cmpeq_epi16(bucketB, fingerprintSIMD);
__m128i bothCompare = _mm_or_si128(bucketACompare, bucketBCompare);
return !!_mm_movemask_epi8(bothCompare);
#elif defined(USE_ARM_INTRINSICS_FOR_CUCKOO_FILTER)
uint16x8_t bucketA = vld1q_u16((uint16_t*)&((uint16x8_t*)_base)[bucketAIndex]);
uint16x8_t bucketB = vld1q_u16((uint16_t*)&((uint16x8_t*)_base)[bucketBIndex]);
uint16x8_t fingerprintSIMD = vdupq_n_u16(fingerprint);
uint16x8_t bucketACompare = vceqq_u16(bucketA, fingerprintSIMD);
uint16x8_t bucketBCompare = vceqq_u16(bucketB, fingerprintSIMD);
uint16x8_t bothCompare = vorrq_u16(bucketACompare, bucketBCompare);
uint64_t bits0Lane = vgetq_lane_u64(bothCompare, 0);
uint64_t bits1Lane = vgetq_lane_u64(bothCompare, 1);
return !!(bits0Lane | bits1Lane);
#else // Non-intrinsic implementation supporting NativeReader to cross DAC boundary
NativeReader reader(_base, _size);
// Check for existence in bucketA
for (int i = 0; i < 8; i++)
{
if (reader.ReadUInt16(bucketAIndex * 16 + i * sizeof(UInt16)) == fingerprint)
return true;
}
// Check for existence in bucketB
for (int i = 0; i < 8; i++)
{
if (reader.ReadUInt16(bucketBIndex * 16 + i * sizeof(UInt16)) == fingerprint)
return true;
}
return false;
#endif
}
};
}