dyld3/ClosureWriter.cpp

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 #include <stdint.h>
  26 #include <assert.h>
  27 #include <uuid/uuid.h>
  28 #include <unistd.h>
  29 #include <limits.h>
  30 #include <mach/vm_page_size.h>
  31
  32 #include "ClosureWriter.h"
  33 #include "MachOFile.h"
  34
  35
  36 namespace dyld3 {
  37 namespace closure {
  38
  39
  40 ////////////////////////////  ContainerTypedBytesWriter ////////////////////////////////////////
  41
  42
  43 void ContainerTypedBytesWriter::setContainerType(TypedBytes::Type containerType)
  44 {
  45     assert(_vmAllocationStart == 0);
  46     _vmAllocationSize = 1024 * 1024;
  47     vm_address_t allocationAddr;
  48     ::vm_allocate(mach_task_self(), &allocationAddr, _vmAllocationSize, VM_FLAGS_ANYWHERE);
  49     assert(allocationAddr != 0);
  50     _vmAllocationStart = (void*)allocationAddr;
  51     _containerTypedBytes =  (TypedBytes*)_vmAllocationStart;
  52     _containerTypedBytes->type = containerType;
  53     _containerTypedBytes->payloadLength = 0;
  54     _end = (uint8_t*)_vmAllocationStart + sizeof(TypedBytes);
  55 }
  56
  57 void* ContainerTypedBytesWriter::append(TypedBytes::Type t, const void* payload, uint32_t payloadSize)
  58 {
  59     assert((payloadSize & 0x3) == 0);
  60     if ( (uint8_t*)_end + payloadSize >= (uint8_t*)_vmAllocationStart + _vmAllocationSize ) {
  61         // if current buffer too small, grow it
  62         size_t growth = _vmAllocationSize;
  63         if ( growth < payloadSize )
  64             growth = _vmAllocationSize*((payloadSize/_vmAllocationSize)+1);
  65         vm_address_t newAllocationAddr;
  66         size_t newAllocationSize = _vmAllocationSize+growth;
  67         ::vm_allocate(mach_task_self(), &newAllocationAddr, newAllocationSize, VM_FLAGS_ANYWHERE);
  68             assert(newAllocationAddr != 0);
  69         size_t currentInUse = (char*)_end - (char*)_vmAllocationStart;
  70         memcpy((void*)newAllocationAddr, _vmAllocationStart, currentInUse);
  71         ::vm_deallocate(mach_task_self(), (vm_address_t)_vmAllocationStart, _vmAllocationSize);
  72         _end                 = (void*)(newAllocationAddr + currentInUse);
  73         _vmAllocationStart   = (void*)newAllocationAddr;
  74         _containerTypedBytes = (TypedBytes*)_vmAllocationStart;
  75         _vmAllocationSize    = newAllocationSize;
  76     }
  77     assert( (uint8_t*)_end + payloadSize < (uint8_t*)_vmAllocationStart + _vmAllocationSize);
  78     TypedBytes* tb = (TypedBytes*)_end;
  79     tb->type   = t;
  80     tb->payloadLength = payloadSize;
  81     if ( payload != nullptr )
  82         ::memcpy(tb->payload(), payload, payloadSize);
  83     _end = (uint8_t*)_end + sizeof(TypedBytes) + payloadSize;
  84     assert((_containerTypedBytes->payloadLength + sizeof(TypedBytes) + payloadSize) < (16 * 1024 * 1024));
  85     _containerTypedBytes->payloadLength += sizeof(TypedBytes) + payloadSize;
  86     return tb->payload();
  87 }
  88
  89 const void* ContainerTypedBytesWriter::finalizeContainer()
  90 {
  91     // trim vm allocation down to just what is needed
  92     uintptr_t bufferStart = (uintptr_t)_vmAllocationStart;
  93     uintptr_t used = round_page((uintptr_t)_end - bufferStart);
  94     if ( used < _vmAllocationSize ) {
  95         uintptr_t deallocStart = bufferStart + used;
  96         ::vm_deallocate(mach_task_self(), deallocStart, _vmAllocationSize - used);
  97         _end = nullptr;
  98         _vmAllocationSize = used;
  99     }
 100     // mark vm region read-only
 101     ::vm_protect(mach_task_self(), bufferStart, used, false, VM_PROT_READ);
 102     return (void*)_vmAllocationStart;
 103 }
 104
 105 const void* ContainerTypedBytesWriter::currentTypedBytes()
 106 {
 107     return (void*)_vmAllocationStart;
 108 }
 109
 110 void ContainerTypedBytesWriter::deallocate()
 111 {
 112     ::vm_deallocate(mach_task_self(), (long)_vmAllocationStart, _vmAllocationSize);
 113 }
 114
 115 ////////////////////////////  ImageWriter ////////////////////////////////////////
 116
 117
 118 const Image* ImageWriter::finalize()
 119 {
 120     return (Image*)finalizeContainer();
 121 }
 122
 123 const Image* ImageWriter::currentImage()
 124 {
 125     return (Image*)currentTypedBytes();
 126 }
 127
 128 void ImageWriter::addPath(const char* path)
 129 {
 130     uint32_t roundedPathLen = ((uint32_t)strlen(path) + 1 + 3) & (-4);
 131     Image::PathAndHash* ph = (Image::PathAndHash*)append(TypedBytes::Type::pathWithHash, nullptr, sizeof(Image::PathAndHash)+roundedPathLen);
 132     ph->hash = Image::hashFunction(path);
 133     strcpy(ph->path, path);
 134 }
 135
 136 Image::Flags& ImageWriter::getFlags()
 137 {
 138     if ( _flagsOffset == -1 ) {
 139         setContainerType(TypedBytes::Type::image);
 140         Image::Flags flags;
 141         ::bzero(&flags, sizeof(flags));
 142         uint8_t* p = (uint8_t*)append(TypedBytes::Type::imageFlags, &flags, sizeof(flags));
 143         _flagsOffset = (int)(p - (uint8_t*)currentTypedBytes());
 144     }
 145     return *((Image::Flags*)((uint8_t*)currentTypedBytes() + _flagsOffset));
 146 }
 147
 148 void ImageWriter::setImageNum(ImageNum num)
 149 {
 150    getFlags().imageNum = num;
 151 }
 152
 153 void ImageWriter::setHasObjC(bool value)
 154 {
 155     getFlags().hasObjC = value;
 156 }
 157
 158 void ImageWriter::setIs64(bool value)
 159 {
 160     getFlags().is64 = value;
 161 }
 162
 163 void ImageWriter::setHasPlusLoads(bool value)
 164 {
 165     getFlags().mayHavePlusLoads = value;
 166 }
 167
 168 void ImageWriter::setIsBundle(bool value)
 169 {
 170     getFlags().isBundle = value;
 171 }
 172
 173 void ImageWriter::setIsDylib(bool value)
 174 {
 175     getFlags().isDylib = value;
 176 }
 177
 178 void ImageWriter::setIsExecutable(bool value)
 179 {
 180     getFlags().isExecutable = value;
 181 }
 182
 183 void ImageWriter::setHasWeakDefs(bool value)
 184 {
 185     getFlags().hasWeakDefs = value;
 186 }
 187
 188 void ImageWriter::setUses16KPages(bool value)
 189 {
 190     getFlags().has16KBpages = value;
 191 }
 192
 193 void ImageWriter::setOverridableDylib(bool value)
 194 {
 195     getFlags().overridableDylib = value;
 196 }
 197
 198 void ImageWriter::setInvalid()
 199 {
 200     getFlags().isInvalid = true;
 201 }
 202
 203 void ImageWriter::setInDyldCache(bool value)
 204 {
 205     getFlags().inDyldCache = value;
 206 }
 207
 208 void ImageWriter::setHasPrecomputedObjC(bool value)
 209 {
 210     getFlags().hasPrecomputedObjC = value;
 211 }
 212
 213 void ImageWriter::setNeverUnload(bool value)
 214 {
 215     getFlags().neverUnload = value;
 216 }
 217
 218 void ImageWriter::setUUID(const uuid_t uuid)
 219 {
 220     append(TypedBytes::Type::uuid, uuid, sizeof(uuid_t));
 221 }
 222
 223 void ImageWriter::addCDHash(const uint8_t cdHash[20])
 224 {
 225     append(TypedBytes::Type::cdHash, cdHash, 20);
 226 }
 227
 228 void ImageWriter::setDependents(const Array<Image::LinkedImage>& deps)
 229 {
 230     append(TypedBytes::Type::dependents, deps.begin(), (uint32_t)deps.count()*sizeof(Image::LinkedImage));
 231 }
 232
 233 void ImageWriter::setDofOffsets(const Array<uint32_t>& dofSectionOffsets)
 234 {
 235     append(TypedBytes::Type::dofOffsets, &dofSectionOffsets[0], (uint32_t)dofSectionOffsets.count()*sizeof(uint32_t));
 236 }
 237
 238 void ImageWriter::setInitOffsets(const uint32_t initOffsets[], uint32_t count)
 239 {
 240     append(TypedBytes::Type::initOffsets, initOffsets, count*sizeof(uint32_t));
 241 }
 242
 243 void ImageWriter::setTermOffsets(const uint32_t termOffsets[], uint32_t count)
 244 {
 245     getFlags().hasTerminators = true;
 246     append(TypedBytes::Type::termOffsets, termOffsets, count*sizeof(uint32_t));
 247 }
 248
 249 void ImageWriter::setInitSectRange(uint32_t sectionOffset, uint32_t sectionSize)
 250 {
 251     Image::InitializerSectionRange range = { sectionOffset, sectionSize };
 252     append(TypedBytes::Type::initsSection, &range, sizeof(Image::InitializerSectionRange));
 253 }
 254
 255 void ImageWriter::setDiskSegments(const Image::DiskSegment segs[], uint32_t count)
 256 {
 257     append(TypedBytes::Type::diskSegment, segs, count*sizeof(Image::DiskSegment));
 258     for (uint32_t i=0; i < count; ++i) {
 259         if ( segs[i].permissions == Image::DiskSegment::kReadOnlyDataPermissions )
 260             getFlags().hasReadOnlyData = true;
 261     }
 262 }
 263
 264 void ImageWriter::setCachedSegments(const Image::DyldCacheSegment segs[], uint32_t count)
 265 {
 266     append(TypedBytes::Type::cacheSegment, segs, count*sizeof(Image::DyldCacheSegment));
 267 }
 268
 269 void ImageWriter::setCodeSignatureLocation(uint32_t fileOffset, uint32_t size)
 270 {
 271     Image::CodeSignatureLocation loc;
 272     loc.fileOffset = fileOffset;
 273     loc.fileSize   = size;
 274     append(TypedBytes::Type::codeSignLoc, &loc, sizeof(loc));
 275 }
 276
 277 void ImageWriter::setFairPlayEncryptionRange(uint32_t fileOffset, uint32_t size)
 278 {
 279     Image::FairPlayRange loc;
 280     loc.rangeStart = fileOffset;
 281     loc.rangeLength = size;
 282     append(TypedBytes::Type::fairPlayLoc, &loc, sizeof(loc));
 283 }
 284
 285 void ImageWriter::setMappingInfo(uint64_t sliceOffset, uint64_t vmSize)
 286 {
 287     const uint32_t pageSize = getFlags().has16KBpages ? 0x4000 : 0x1000;
 288     Image::MappingInfo info;
 289     info.sliceOffsetIn4K = (uint32_t)(sliceOffset / 0x1000);
 290     info.totalVmPages    = (uint32_t)(vmSize / pageSize);
 291     append(TypedBytes::Type::mappingInfo, &info, sizeof(info));
 292 }
 293
 294 void ImageWriter::setFileInfo(uint64_t inode, uint64_t mTime)
 295 {
 296     Image::FileInfo info = { inode, mTime };
 297     append(TypedBytes::Type::fileInodeAndTime, &info, sizeof(info));
 298 }
 299
 300 void ImageWriter::setRebaseInfo(const Array<Image::RebasePattern>& fixups)
 301 {
 302     append(TypedBytes::Type::rebaseFixups, fixups.begin(), (uint32_t)fixups.count()*sizeof(Image::RebasePattern));
 303 }
 304
 305 void ImageWriter::setTextRebaseInfo(const Array<Image::TextFixupPattern>& fixups)
 306 {
 307     append(TypedBytes::Type::textFixups, fixups.begin(), (uint32_t)fixups.count()*sizeof(Image::TextFixupPattern));
 308 }
 309
 310 void ImageWriter::setBindInfo(const Array<Image::BindPattern>& fixups)
 311 {
 312     append(TypedBytes::Type::bindFixups, fixups.begin(), (uint32_t)fixups.count()*sizeof(Image::BindPattern));
 313 }
 314
 315 void ImageWriter::setChainedFixups(uint64_t runtimeStartsStructOffset, const Array<Image::ResolvedSymbolTarget>& targets)
 316 {
 317     getFlags().hasChainedFixups = true;
 318     append(TypedBytes::Type::chainedStartsOffset, &runtimeStartsStructOffset, sizeof(uint64_t));
 319     append(TypedBytes::Type::chainedFixupsTargets, targets.begin(), (uint32_t)targets.count()*sizeof(Image::ResolvedSymbolTarget));
 320 }
 321
 322 void ImageWriter::setObjCFixupInfo(const Image::ResolvedSymbolTarget& objcProtocolClassTarget,
 323                                    uint64_t objcImageInfoVMOffset,
 324                                    const Array<Image::ProtocolISAFixup>& protocolISAFixups,
 325                                    const Array<Image::SelectorReferenceFixup>& selRefFixups,
 326                                    const Array<Image::ClassStableSwiftFixup>& classStableSwiftFixups,
 327                                    const Array<Image::MethodListFixup>& methodListFixups)
 328 {
 329     // The layout here is:
 330     //   ResolvedSymbolTarget
 331     //   uint64_t vmOffset to objc_imageinfo
 332     //   uint32_t protocol count
 333     //   uint32_t selector reference count
 334     //   array of ProtocolISAFixup
 335     //   array of SelectorReferenceFixup
 336     //   optional uint32_t stable swift fixup count
 337     //   optional uint32_t method list fixup count
 338     //   optional array of ClassStableSwiftFixup
 339     //   optional array of MethodListFixup
 340
 341     uint64_t headerSize = sizeof(Image::ResolvedSymbolTarget) + sizeof(uint64_t) + (sizeof(uint32_t) * 4);
 342     uint64_t protocolsSize = (sizeof(Image::ProtocolISAFixup) * protocolISAFixups.count());
 343     uint64_t selRefsSize = (sizeof(Image::SelectorReferenceFixup) * selRefFixups.count());
 344     uint64_t stableSwiftSize = (sizeof(Image::ClassStableSwiftFixup) * classStableSwiftFixups.count());
 345     uint64_t methodListSize = (sizeof(Image::MethodListFixup) * methodListFixups.count());
 346
 347     uint64_t totalSize = headerSize + protocolsSize + selRefsSize + stableSwiftSize + methodListSize;
 348     assert( (totalSize & 3) == 0);
 349     uint8_t* buffer = (uint8_t*)append(TypedBytes::Type::objcFixups, nullptr, (uint32_t)totalSize);
 350
 351     // Set the statically sized data
 352     uint32_t protocolFixupCount = (uint32_t)protocolISAFixups.count();
 353     uint32_t selRefFixupCount = (uint32_t)selRefFixups.count();
 354     memcpy(buffer, &objcProtocolClassTarget, sizeof(Image::ResolvedSymbolTarget));
 355     buffer += sizeof(Image::ResolvedSymbolTarget);
 356     memcpy(buffer, &objcImageInfoVMOffset, sizeof(uint64_t));
 357     buffer += sizeof(uint64_t);
 358     memcpy(buffer, &protocolFixupCount, sizeof(uint32_t));
 359     buffer += sizeof(uint32_t);
 360     memcpy(buffer, &selRefFixupCount, sizeof(uint32_t));
 361     buffer += sizeof(uint32_t);
 362
 363     // Set the protocol fixups
 364     if ( protocolFixupCount != 0 ) {
 365         memcpy(buffer, protocolISAFixups.begin(), (size_t)protocolsSize);
 366         buffer += protocolsSize;
 367     }
 368
 369     // Set the selector reference fixups
 370     if ( selRefFixupCount != 0 ) {
 371         memcpy(buffer, selRefFixups.begin(), (size_t)selRefsSize);
 372         buffer += selRefsSize;
 373     }
 374
 375     // New closures get additional fixups.  These are ignored by old dyld's
 376     uint32_t stableSwiftFixupCount = (uint32_t)classStableSwiftFixups.count();
 377     uint32_t methodListFixupCount = (uint32_t)methodListFixups.count();
 378     memcpy(buffer, &stableSwiftFixupCount, sizeof(uint32_t));
 379     buffer += sizeof(uint32_t);
 380     memcpy(buffer, &methodListFixupCount, sizeof(uint32_t));
 381     buffer += sizeof(uint32_t);
 382
 383     // Set the stable swift fixups
 384     if ( stableSwiftFixupCount != 0 ) {
 385         memcpy(buffer, classStableSwiftFixups.begin(), (size_t)stableSwiftSize);
 386         buffer += stableSwiftSize;
 387     }
 388
 389     // Set the method list fixups
 390     if ( methodListFixupCount != 0 ) {
 391         memcpy(buffer, methodListFixups.begin(), (size_t)methodListSize);
 392         buffer += methodListSize;
 393     }
 394 }
 395
 396 void ImageWriter::setAsOverrideOf(ImageNum imageNum)
 397 {
 398     uint32_t temp = imageNum;
 399     append(TypedBytes::Type::imageOverride, &temp, sizeof(temp));
 400 }
 401
 402 void ImageWriter::setInitsOrder(const ImageNum images[], uint32_t count)
 403 {
 404     append(TypedBytes::Type::initBefores, images, count*sizeof(ImageNum));
 405 }
 406
 407
 408 ////////////////////////////  ImageArrayWriter ////////////////////////////////////////
 409
 410
 411 ImageArrayWriter::ImageArrayWriter(ImageNum startImageNum, unsigned count, bool hasRoots) : _index(0)
 412 {
 413     setContainerType(TypedBytes::Type::imageArray);
 414     _end = (void*)((uint8_t*)_end + sizeof(ImageArray) - sizeof(TypedBytes) + sizeof(uint32_t)*count);
 415     _containerTypedBytes->payloadLength = sizeof(ImageArray) - sizeof(TypedBytes) + sizeof(uint32_t)*count;
 416     ImageArray* ia = (ImageArray*)_containerTypedBytes;
 417     ia->firstImageNum   = startImageNum;
 418     ia->count           = count;
 419     ia->hasRoots        = hasRoots;
 420 }
 421
 422 void ImageArrayWriter::appendImage(const Image* image)
 423 {
 424     ImageArray* ia = (ImageArray*)_containerTypedBytes;
 425     ia->offsets[_index++] = _containerTypedBytes->payloadLength;
 426     append(TypedBytes::Type::image, image->payload(), image->payloadLength);
 427 }
 428
 429 const ImageArray* ImageArrayWriter::finalize()
 430 {
 431     return (ImageArray*)finalizeContainer();
 432 }
 433
 434
 435 ////////////////////////////  ClosureWriter ////////////////////////////////////////
 436
 437 void ClosureWriter::setTopImageNum(ImageNum imageNum)
 438 {
 439     append(TypedBytes::Type::topImage, &imageNum, sizeof(ImageNum));
 440 }
 441
 442 void ClosureWriter::addCachePatches(const Array<Closure::PatchEntry>& patches)
 443 {
 444     append(TypedBytes::Type::cacheOverrides, patches.begin(), (uint32_t)patches.count()*sizeof(Closure::PatchEntry));
 445 }
 446
 447 void ClosureWriter::applyInterposing(const LaunchClosure* launchClosure)
 448 {
 449     const Closure*       currentClosure = (Closure*)currentTypedBytes();
 450         const ImageArray*    images         = currentClosure->images();
 451         launchClosure->forEachInterposingTuple(^(const InterposingTuple& tuple, bool&) {
 452         images->forEachImage(^(const dyld3::closure::Image* image, bool&) {
 453             for (const Image::BindPattern& bindPat : image->bindFixups()) {
 454                 if ( (bindPat.target == tuple.stockImplementation) && (tuple.newImplementation.image.imageNum != image->imageNum()) ) {
 455                     Image::BindPattern* writePat = const_cast<Image::BindPattern*>(&bindPat);
 456                     writePat->target = tuple.newImplementation;
 457                 }
 458             }
 459
 460             // Chained fixups may also be interposed.  We can't change elements in the chain, but we can change
 461             // the target list.
 462             for (const Image::ResolvedSymbolTarget& symbolTarget : image->chainedTargets()) {
 463                 if ( (symbolTarget == tuple.stockImplementation) && (tuple.newImplementation.image.imageNum != image->imageNum()) ) {
 464                     Image::ResolvedSymbolTarget* writeTarget = const_cast<Image::ResolvedSymbolTarget*>(&symbolTarget);
 465                     *writeTarget = tuple.newImplementation;
 466                 }
 467             }
 468         });
 469     });
 470 }
 471
 472 void ClosureWriter::addWarning(Closure::Warning::Type warningType, const char* warning)
 473 {
 474     uint32_t roundedMessageLen = ((uint32_t)strlen(warning) + 1 + 3) & (-4);
 475     Closure::Warning* ph = (Closure::Warning*)append(TypedBytes::Type::warning, nullptr, sizeof(Closure::Warning)+roundedMessageLen);
 476     ph->type = warningType;
 477     strcpy(ph->message, warning);
 478 }
 479
 480
 481 ////////////////////////////  LaunchClosureWriter ////////////////////////////////////////
 482
 483 LaunchClosureWriter::LaunchClosureWriter(const ImageArray* images)
 484 {
 485     setContainerType(TypedBytes::Type::launchClosure);
 486     append(TypedBytes::Type::imageArray, images->payload(), images->payloadLength);
 487 }
 488
 489 const LaunchClosure* LaunchClosureWriter::finalize()
 490 {
 491     return (LaunchClosure*)finalizeContainer();
 492 }
 493
 494 void LaunchClosureWriter::setLibSystemImageNum(ImageNum imageNum)
 495 {
 496     append(TypedBytes::Type::libSystemNum, &imageNum, sizeof(ImageNum));
 497 }
 498
 499 void LaunchClosureWriter::setLibDyldEntry(Image::ResolvedSymbolTarget entry)
 500 {
 501     append(TypedBytes::Type::libDyldEntry, &entry, sizeof(entry));
 502 }
 503
 504 void LaunchClosureWriter::setMainEntry(Image::ResolvedSymbolTarget main)
 505 {
 506     append(TypedBytes::Type::mainEntry, &main, sizeof(main));
 507 }
 508
 509 void LaunchClosureWriter::setStartEntry(Image::ResolvedSymbolTarget start)
 510 {
 511     append(TypedBytes::Type::startEntry, &start, sizeof(start));
 512 }
 513
 514 void LaunchClosureWriter::setUsedFallbackPaths(bool value)
 515 {
 516     getFlags().usedFallbackPaths = value;
 517 }
 518
 519 void LaunchClosureWriter::setUsedAtPaths(bool value)
 520 {
 521     getFlags().usedAtPaths = value;
 522 }
 523
 524 void LaunchClosureWriter::setHasInsertedLibraries(bool value)
 525 {
 526     getFlags().hasInsertedLibraries = value;
 527 }
 528
 529 void LaunchClosureWriter::setInitImageCount(uint32_t count)
 530 {
 531     getFlags().initImageCount = count;
 532 }
 533
 534 LaunchClosure::Flags& LaunchClosureWriter::getFlags()
 535 {
 536     if ( _flagsOffset == -1 ) {
 537         LaunchClosure::Flags flags;
 538         ::bzero(&flags, sizeof(flags));
 539         uint8_t* p = (uint8_t*)append(TypedBytes::Type::closureFlags, &flags, sizeof(flags));
 540         _flagsOffset = (int)(p - (uint8_t*)currentTypedBytes());
 541     }
 542     return *((LaunchClosure::Flags*)((uint8_t*)currentTypedBytes() + _flagsOffset));
 543 }
 544
 545 void LaunchClosureWriter::setMustBeMissingFiles(const Array<const char*>& paths)
 546 {
 547     uint32_t totalSize = 0;
 548     for (const char* s : paths)
 549         totalSize += (strlen(s) +1);
 550     totalSize = (totalSize + 3) & (-4); // align
 551
 552     char* buffer = (char*)append(TypedBytes::Type::missingFiles, nullptr, totalSize);
 553     char* t = buffer;
 554     for (const char* path : paths) {
 555         for (const char* s=path; *s != '\0'; ++s)
 556             *t++ = *s;
 557         *t++ = '\0';
 558     }
 559     while (t < &buffer[totalSize])
 560         *t++ = '\0';
 561 }
 562
 563 void LaunchClosureWriter::setMustExistFiles(const Array<LaunchClosure::SkippedFile>& files)
 564 {
 565     // Start the structure with a count
 566     uint32_t totalSize = sizeof(uint64_t);
 567
 568     // Then make space for the array of mod times and inode numbers
 569     totalSize += files.count() * sizeof(uint64_t) * 2;
 570
 571     // Then the array of paths on the end
 572     for (const LaunchClosure::SkippedFile& file : files)
 573         totalSize += (strlen(file.path) + 1);
 574     totalSize = (totalSize + 3) & (-4); // align
 575
 576     char* buffer = (char*)append(TypedBytes::Type::existingFiles, nullptr, totalSize);
 577
 578     // Set the size
 579     uint64_t* bufferPtr = (uint64_t*)buffer;
 580     *bufferPtr++ = (uint64_t)files.count();
 581
 582     // And the array of mod times and inode numbers
 583     for (const LaunchClosure::SkippedFile& file : files) {
 584         *bufferPtr++ = file.inode;
 585         *bufferPtr++ = file.mtime;
 586     }
 587
 588     char* t = (char*)bufferPtr;
 589     for (const LaunchClosure::SkippedFile& file : files) {
 590         for (const char* s=file.path; *s != '\0'; ++s)
 591             *t++ = *s;
 592         *t++ = '\0';
 593     }
 594     while (t < &buffer[totalSize])
 595         *t++ = '\0';
 596 }
 597
 598 void LaunchClosureWriter::addEnvVar(const char* envVar)
 599 {
 600     unsigned len = (unsigned)strlen(envVar);
 601     char temp[len+8];
 602     strcpy(temp, envVar);
 603     unsigned paddedSize = len+1;
 604     while ( (paddedSize % 4) != 0 )
 605         temp[paddedSize++] = '\0';
 606     append(TypedBytes::Type::envVar, temp, paddedSize);
 607 }
 608
 609 void LaunchClosureWriter::addInterposingTuples(const Array<InterposingTuple>& tuples)
 610 {
 611     append(TypedBytes::Type::interposeTuples, tuples.begin(), (uint32_t)tuples.count()*sizeof(InterposingTuple));
 612 }
 613
 614 void LaunchClosureWriter::setDyldCacheUUID(const uuid_t uuid)
 615 {
 616     append(TypedBytes::Type::dyldCacheUUID, uuid, sizeof(uuid_t));
 617 }
 618
 619 void LaunchClosureWriter::setBootUUID(const char* uuid)
 620 {
 621     unsigned len = (unsigned)strlen(uuid);
 622     char temp[len+8];
 623     strcpy(temp, uuid);
 624     unsigned paddedSize = len+1;
 625     while ( (paddedSize % 4) != 0 )
 626         temp[paddedSize++] = '\0';
 627     append(TypedBytes::Type::bootUUID, temp, paddedSize);
 628 }
 629
 630 void LaunchClosureWriter::setObjCSelectorInfo(const Array<uint8_t>& hashTable, const Array<Image::ObjCSelectorImage>& hashTableImages) {
 631     uint32_t count = (uint32_t)hashTableImages.count();
 632     uint32_t totalSize = (uint32_t)(sizeof(count) + (sizeof(Image::ObjCSelectorImage) * count) + hashTable.count());
 633     totalSize = (totalSize + 3) & (-4); // align
 634     uint8_t* buffer = (uint8_t*)append(TypedBytes::Type::selectorTable, nullptr, totalSize);
 635
 636     // Write out out the image count
 637     memcpy(buffer, &count, sizeof(count));
 638     buffer += sizeof(count);
 639
 640     // Write out out the image nums
 641     memcpy(buffer, hashTableImages.begin(), sizeof(Image::ObjCSelectorImage) * count);
 642     buffer += sizeof(Image::ObjCSelectorImage) * count;
 643
 644     // Write out out the image count
 645     memcpy(buffer, hashTable.begin(), hashTable.count());
 646 }
 647
 648 void LaunchClosureWriter::setObjCClassAndProtocolInfo(const Array<uint8_t>& classHashTable, const Array<uint8_t>& protocolHashTable,
 649                                                       const Array<Image::ObjCClassImage>& hashTableImages) {
 650     // The layout here is:
 651     //   uint32_t offset to class table (note this is 0 if there are no classes)
 652     //   uint32_t offset to protocol table (note this is 0 if there are no protocols)
 653     //   uint32_t num images
 654     //   ObjCClassImage[num images]
 655     //   class hash table
 656     //   [ padding to 4-byte alignment if needed
 657     //   protocol hash table
 658     //   [ padding to 4-byte alignment if needed
 659
 660     uint32_t numImages = (uint32_t)hashTableImages.count();
 661
 662     uint32_t headerSize = sizeof(uint32_t) * 3;
 663     uint32_t imagesSize = (sizeof(Image::ObjCClassImage) * numImages);
 664     uint32_t classTableSize = ((uint32_t)classHashTable.count() + 3) & (-4); // pad to 4-byte multiple
 665     uint32_t protocolTableSize = ((uint32_t)protocolHashTable.count() + 3) & (-4); // pad to 4-byte multiple
 666     uint32_t offsetToClassTable = (classTableSize == 0) ? 0 : (headerSize + imagesSize);
 667     uint32_t offsetToProtocolTable = (protocolTableSize == 0) ? 0 : (headerSize + imagesSize + classTableSize);
 668
 669     uint32_t totalSize = headerSize + imagesSize + classTableSize + protocolTableSize;
 670     assert( (totalSize & 3) == 0);
 671     uint8_t* buffer = (uint8_t*)append(TypedBytes::Type::classTable, nullptr, totalSize);
 672
 673     // Write out out the header
 674     memcpy(buffer + 0, &offsetToClassTable, sizeof(uint32_t));
 675     memcpy(buffer + 4, &offsetToProtocolTable, sizeof(uint32_t));
 676     memcpy(buffer + 8, &numImages, sizeof(uint32_t));
 677
 678     // Write out out the image nums
 679     memcpy(buffer + headerSize, hashTableImages.begin(), imagesSize);
 680
 681     // Write out out the class hash table
 682     if ( offsetToClassTable != 0 )
 683         memcpy(buffer + offsetToClassTable, classHashTable.begin(), classHashTable.count());
 684
 685     // Write out out the protocol hash table
 686     if ( offsetToProtocolTable != 0 )
 687         memcpy(buffer + offsetToProtocolTable, protocolHashTable.begin(), protocolHashTable.count());
 688 }
 689
 690 void LaunchClosureWriter::setObjCDuplicateClassesInfo(const Array<uint8_t>& hashTable) {
 691     uint32_t totalSize = (uint32_t)hashTable.count();
 692     totalSize = (totalSize + 3) & (-4); // align
 693     uint8_t* buffer = (uint8_t*)append(TypedBytes::Type::duplicateClassesTable, nullptr, totalSize);
 694
 695     // Write out out the hash table
 696     memcpy(buffer, hashTable.begin(), hashTable.count());
 697 }
 698
 699 ////////////////////////////  DlopenClosureWriter ////////////////////////////////////////
 700
 701 DlopenClosureWriter::DlopenClosureWriter(const ImageArray* images)
 702 {
 703     setContainerType(TypedBytes::Type::dlopenClosure);
 704     append(TypedBytes::Type::imageArray, images->payload(), images->payloadLength);
 705 }
 706
 707 const DlopenClosure* DlopenClosureWriter::finalize()
 708 {
 709     return (DlopenClosure*)finalizeContainer();
 710 }
 711
 712
 713 } // namespace closure
 714 } // namespace dyld3
 715
 716
 717