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+++ dyld/dyld-733.6/launch-cache/dsc_extractor.cpp
@@ -0,0 +1,883 @@
+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2011 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include <sys/syslimits.h>
+#include <libkern/OSByteOrder.h>
+#include <mach-o/arch.h>
+#include <mach-o/loader.h>
+#include <Availability.h>
+
+#include "CodeSigningTypes.h"
+#include <CommonCrypto/CommonHMAC.h>
+#include <CommonCrypto/CommonDigest.h>
+#include <CommonCrypto/CommonDigestSPI.h>
+
+#define NO_ULEB
+#include "Architectures.hpp"
+#include "MachOFileAbstraction.hpp"
+#include "CacheFileAbstraction.hpp"
+
+#include "dsc_iterator.h"
+#include "dsc_extractor.h"
+#include "MachOTrie.hpp"
+#include "SupportedArchs.h"
+#include "DyldSharedCache.h"
+
+#include <vector>
+#include <set>
+#include <map>
+#include <unordered_map>
+#include <algorithm>
+#include <dispatch/dispatch.h>
+
+struct seg_info
+{
+ seg_info(const char* n, uint64_t o, uint64_t s)
+ : segName(n), offset(o), sizem(s) { }
+ const char* segName;
+ uint64_t offset;
+ uint64_t sizem;
+};
+
+class CStringHash {
+public:
+ size_t operator()(const char* __s) const {
+ size_t __h = 0;
+ for ( ; *__s; ++__s)
+ __h = 5 * __h + *__s;
+ return __h;
+ };
+};
+class CStringEquals {
+public:
+ bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); }
+};
+typedef std::unordered_map<const char*, std::vector<seg_info>, CStringHash, CStringEquals> NameToSegments;
+
+// Filter to find individual symbol re-exports in trie
+class NotReExportSymbol {
+public:
+ NotReExportSymbol(const std::set<int> &rd) :_reexportDeps(rd) {}
+ bool operator()(const mach_o::trie::Entry &entry) const {
+ bool result = isSymbolReExport(entry);
+ if (result) {
+ // <rdar://problem/17671438> Xcode 6 leaks in dyld_shared_cache_extract_dylibs
+ ::free((void*)entry.name);
+ const_cast<mach_o::trie::Entry*>(&entry)->name = NULL;
+ }
+ return result;
+ }
+private:
+ bool isSymbolReExport(const mach_o::trie::Entry &entry) const {
+ if ( (entry.flags & EXPORT_SYMBOL_FLAGS_KIND_MASK) != EXPORT_SYMBOL_FLAGS_KIND_REGULAR )
+ return true;
+ if ( (entry.flags & EXPORT_SYMBOL_FLAGS_REEXPORT) == 0 )
+ return true;
+ // If the symbol comes from a dylib that is re-exported, this is not an individual symbol re-export
+ if ( _reexportDeps.count((int)entry.other) != 0 )
+ return true;
+ return false;
+ }
+ const std::set<int> &_reexportDeps;
+};
+
+template <typename P>
+struct LoadCommandInfo {
+};
+
+template <typename A>
+class LinkeditOptimizer {
+ typedef typename A::P P;
+ typedef typename A::P::E E;
+ typedef typename A::P::uint_t pint_t;
+
+private:
+ macho_segment_command<P>* linkEditSegCmd = NULL;
+ macho_symtab_command<P>* symtab = NULL;
+ macho_dysymtab_command<P>* dynamicSymTab = NULL;
+ macho_linkedit_data_command<P>* functionStarts = NULL;
+ macho_linkedit_data_command<P>* dataInCode = NULL;
+ uint32_t exportsTrieOffset = 0;
+ uint32_t exportsTrieSize = 0;
+ std::set<int> reexportDeps;
+
+public:
+
+ void optimize_loadcommands(macho_header<typename A::P>* mh)
+ {
+ typedef typename A::P P;
+ typedef typename A::P::E E;
+ typedef typename A::P::uint_t pint_t;
+
+ // update header flags
+ mh->set_flags(mh->flags() & 0x7FFFFFFF); // remove in-cache bit
+
+ // update load commands
+ uint64_t cumulativeFileSize = 0;
+ const unsigned origLoadCommandsSize = mh->sizeofcmds();
+ unsigned bytesRemaining = origLoadCommandsSize;
+ unsigned removedCount = 0;
+ const macho_load_command<P>* const cmds = (macho_load_command<P>*)((uint8_t*)mh + sizeof(macho_header<P>));
+ const uint32_t cmdCount = mh->ncmds();
+ const macho_load_command<P>* cmd = cmds;
+ int depIndex = 0;
+ for (uint32_t i = 0; i < cmdCount; ++i) {
+ bool remove = false;
+ switch ( cmd->cmd() ) {
+ case macho_segment_command<P>::CMD:
+ {
+ // update segment/section file offsets
+ macho_segment_command<P>* segCmd = (macho_segment_command<P>*)cmd;
+ segCmd->set_fileoff(cumulativeFileSize);
+ segCmd->set_filesize(segCmd->vmsize());
+ macho_section<P>* const sectionsStart = (macho_section<P>*)((char*)segCmd + sizeof(macho_segment_command<P>));
+ macho_section<P>* const sectionsEnd = §ionsStart[segCmd->nsects()];
+ for(macho_section<P>* sect = sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( sect->offset() != 0 )
+ sect->set_offset((uint32_t)(cumulativeFileSize+sect->addr()-segCmd->vmaddr()));
+ }
+ if ( strcmp(segCmd->segname(), "__LINKEDIT") == 0 ) {
+ linkEditSegCmd = segCmd;
+ }
+ cumulativeFileSize += segCmd->filesize();
+ break;
+ }
+ case LC_DYLD_INFO_ONLY:
+ {
+ // zero out all dyld info
+ macho_dyld_info_command<P>* dyldInfo = (macho_dyld_info_command<P>*)cmd;
+ exportsTrieOffset = dyldInfo->export_off();
+ exportsTrieSize = dyldInfo->export_size();
+ dyldInfo->set_rebase_off(0);
+ dyldInfo->set_rebase_size(0);
+ dyldInfo->set_bind_off(0);
+ dyldInfo->set_bind_size(0);
+ dyldInfo->set_weak_bind_off(0);
+ dyldInfo->set_weak_bind_size(0);
+ dyldInfo->set_lazy_bind_off(0);
+ dyldInfo->set_lazy_bind_size(0);
+ dyldInfo->set_export_off(0);
+ dyldInfo->set_export_size(0);
+ }
+ break;
+ case LC_SYMTAB:
+ symtab = (macho_symtab_command<P>*)cmd;
+ break;
+ case LC_DYSYMTAB:
+ dynamicSymTab = (macho_dysymtab_command<P>*)cmd;
+ break;
+ case LC_FUNCTION_STARTS:
+ functionStarts = (macho_linkedit_data_command<P>*)cmd;
+ break;
+ case LC_DATA_IN_CODE:
+ dataInCode = (macho_linkedit_data_command<P>*)cmd;
+ break;
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ case LC_LOAD_UPWARD_DYLIB:
+ ++depIndex;
+ if ( cmd->cmd() == LC_REEXPORT_DYLIB ) {
+ reexportDeps.insert(depIndex);
+ }
+ break;
+ case LC_SEGMENT_SPLIT_INFO:
+ // <rdar://problem/23212513> dylibs iOS 9 dyld caches have bogus LC_SEGMENT_SPLIT_INFO
+ remove = true;
+ break;
+ }
+ uint32_t cmdSize = cmd->cmdsize();
+ macho_load_command<P>* nextCmd = (macho_load_command<P>*)(((uint8_t*)cmd)+cmdSize);
+ if ( remove ) {
+ ::memmove((void*)cmd, (void*)nextCmd, bytesRemaining);
+ ++removedCount;
+ }
+ else {
+ bytesRemaining -= cmdSize;
+ cmd = nextCmd;
+ }
+ }
+ // zero out stuff removed
+ ::bzero((void*)cmd, bytesRemaining);
+ // update header
+ mh->set_ncmds(cmdCount - removedCount);
+ mh->set_sizeofcmds(origLoadCommandsSize - bytesRemaining);
+ }
+
+ int optimize_linkedit(std::vector<uint8_t> &new_linkedit_data, uint64_t textOffsetInCache, const void* mapped_cache)
+ {
+ typedef typename A::P P;
+ typedef typename A::P::E E;
+ typedef typename A::P::uint_t pint_t;
+
+ // rebuild symbol table
+ if ( linkEditSegCmd == NULL ) {
+ fprintf(stderr, "__LINKEDIT not found\n");
+ return -1;
+ }
+ if ( symtab == NULL ) {
+ fprintf(stderr, "LC_SYMTAB not found\n");
+ return -1;
+ }
+ if ( dynamicSymTab == NULL ) {
+ fprintf(stderr, "LC_DYSYMTAB not found\n");
+ return -1;
+ }
+
+ const uint64_t newFunctionStartsOffset = new_linkedit_data.size();
+ uint32_t functionStartsSize = 0;
+ if ( functionStarts != NULL ) {
+ // copy function starts from original cache file to new mapped dylib file
+ functionStartsSize = functionStarts->datasize();
+ new_linkedit_data.insert(new_linkedit_data.end(),
+ (char*)mapped_cache + functionStarts->dataoff(),
+ (char*)mapped_cache + functionStarts->dataoff() + functionStartsSize);
+ }
+
+ // pointer align
+ while ((linkEditSegCmd->fileoff() + new_linkedit_data.size()) % sizeof(pint_t))
+ new_linkedit_data.push_back(0);
+
+ const uint64_t newDataInCodeOffset = new_linkedit_data.size();
+ uint32_t dataInCodeSize = 0;
+ if ( dataInCode != NULL ) {
+ // copy data-in-code info from original cache file to new mapped dylib file
+ dataInCodeSize = dataInCode->datasize();
+ new_linkedit_data.insert(new_linkedit_data.end(),
+ (char*)mapped_cache + dataInCode->dataoff(),
+ (char*)mapped_cache + dataInCode->dataoff() + dataInCodeSize);
+ }
+
+ std::vector<mach_o::trie::Entry> exports;
+ if ( exportsTrieSize != 0 ) {
+ const uint8_t* exportsStart = ((uint8_t*)mapped_cache) + exportsTrieOffset;
+ const uint8_t* exportsEnd = &exportsStart[exportsTrieSize];
+ mach_o::trie::parseTrie(exportsStart, exportsEnd, exports);
+ exports.erase(std::remove_if(exports.begin(), exports.end(), NotReExportSymbol(reexportDeps)), exports.end());
+ }
+
+ // look for local symbol info in unmapped part of shared cache
+ dyldCacheHeader<E>* header = (dyldCacheHeader<E>*)mapped_cache;
+ macho_nlist<P>* localNlists = NULL;
+ uint32_t localNlistCount = 0;
+ const char* localStrings = NULL;
+ const char* localStringsEnd = NULL;
+ if ( header->mappingOffset() > offsetof(dyld_cache_header,localSymbolsSize) ) {
+ dyldCacheLocalSymbolsInfo<E>* localInfo = (dyldCacheLocalSymbolsInfo<E>*)(((uint8_t*)mapped_cache) + header->localSymbolsOffset());
+ dyldCacheLocalSymbolEntry<E>* entries = (dyldCacheLocalSymbolEntry<E>*)(((uint8_t*)mapped_cache) + header->localSymbolsOffset() + localInfo->entriesOffset());
+ macho_nlist<P>* allLocalNlists = (macho_nlist<P>*)(((uint8_t*)localInfo) + localInfo->nlistOffset());
+ const uint32_t entriesCount = localInfo->entriesCount();
+ for (uint32_t i=0; i < entriesCount; ++i) {
+ if ( entries[i].dylibOffset() == textOffsetInCache ) {
+ uint32_t localNlistStart = entries[i].nlistStartIndex();
+ localNlistCount = entries[i].nlistCount();
+ localNlists = &allLocalNlists[localNlistStart];
+ localStrings = ((char*)localInfo) + localInfo->stringsOffset();
+ localStringsEnd = &localStrings[localInfo->stringsSize()];
+ break;
+ }
+ }
+ }
+ // compute number of symbols in new symbol table
+ const macho_nlist<P>* const mergedSymTabStart = (macho_nlist<P>*)(((uint8_t*)mapped_cache) + symtab->symoff());
+ const macho_nlist<P>* const mergedSymTabend = &mergedSymTabStart[symtab->nsyms()];
+ uint32_t newSymCount = symtab->nsyms();
+ if ( localNlists != NULL ) {
+ newSymCount = localNlistCount;
+ for (const macho_nlist<P>* s = mergedSymTabStart; s != mergedSymTabend; ++s) {
+ // skip any locals in cache
+ if ( (s->n_type() & (N_TYPE|N_EXT)) == N_SECT )
+ continue;
+ ++newSymCount;
+ }
+ }
+
+ // add room for N_INDR symbols for re-exported symbols
+ newSymCount += exports.size();
+
+ // copy symbol entries and strings from original cache file to new mapped dylib file
+ const char* mergedStringPoolStart = (char*)mapped_cache + symtab->stroff();
+ const char* mergedStringPoolEnd = &mergedStringPoolStart[symtab->strsize()];
+
+ // First count how many entries we need
+ std::vector<macho_nlist<P>> newSymTab;
+ newSymTab.reserve(newSymCount);
+ std::vector<char> newSymNames;
+
+ // first pool entry is always empty string
+ newSymNames.push_back('\0');
+
+ for (const macho_nlist<P>* s = mergedSymTabStart; s != mergedSymTabend; ++s) {
+ // if we have better local symbol info, skip any locals here
+ if ( (localNlists != NULL) && ((s->n_type() & (N_TYPE|N_EXT)) == N_SECT) )
+ continue;
+ macho_nlist<P> t = *s;
+ t.set_n_strx((uint32_t)newSymNames.size());
+ const char* symName = &mergedStringPoolStart[s->n_strx()];
+ if ( symName > mergedStringPoolEnd )
+ symName = "<corrupt symbol name>";
+ newSymNames.insert(newSymNames.end(),
+ symName,
+ symName + (strlen(symName) + 1));
+ newSymTab.push_back(t);
+ }
+ // <rdar://problem/16529213> recreate N_INDR symbols in extracted dylibs for debugger
+ for (std::vector<mach_o::trie::Entry>::iterator it = exports.begin(); it != exports.end(); ++it) {
+ macho_nlist<P> t;
+ memset(&t, 0, sizeof(t));
+ t.set_n_strx((uint32_t)newSymNames.size());
+ t.set_n_type(N_INDR | N_EXT);
+ t.set_n_sect(0);
+ t.set_n_desc(0);
+ newSymNames.insert(newSymNames.end(),
+ it->name,
+ it->name + (strlen(it->name) + 1));
+ const char* importName = it->importName;
+ if ( *importName == '\0' )
+ importName = it->name;
+ t.set_n_value(newSymNames.size());
+ newSymNames.insert(newSymNames.end(),
+ importName,
+ importName + (strlen(importName) + 1));
+ newSymTab.push_back(t);
+ }
+ if ( localNlists != NULL ) {
+ // update load command to reflect new count of locals
+ dynamicSymTab->set_ilocalsym((uint32_t)newSymTab.size());
+ dynamicSymTab->set_nlocalsym(localNlistCount);
+ // copy local symbols
+ for (uint32_t i=0; i < localNlistCount; ++i) {
+ const char* localName = &localStrings[localNlists[i].n_strx()];
+ if ( localName > localStringsEnd )
+ localName = "<corrupt local symbol name>";
+ macho_nlist<P> t = localNlists[i];
+ t.set_n_strx((uint32_t)newSymNames.size());
+ newSymNames.insert(newSymNames.end(),
+ localName,
+ localName + (strlen(localName) + 1));
+ newSymTab.push_back(t);
+ }
+ }
+
+ if ( newSymCount != newSymTab.size() ) {
+ fprintf(stderr, "symbol count miscalculation\n");
+ return -1;
+ }
+
+ //const uint64_t newStringPoolOffset = newIndSymTabOffset + dynamicSymTab->nindirectsyms()*sizeof(uint32_t);
+ //macho_nlist<P>* const newSymTabStart = (macho_nlist<P>*)(((uint8_t*)mh) + newSymTabOffset);
+ //char* const newStringPoolStart = (char*)mh + newStringPoolOffset;
+
+ // pointer align
+ while ((linkEditSegCmd->fileoff() + new_linkedit_data.size()) % sizeof(pint_t))
+ new_linkedit_data.push_back(0);
+
+ const uint64_t newSymTabOffset = new_linkedit_data.size();
+
+ // Copy sym tab
+ for (macho_nlist<P>& sym : newSymTab) {
+ uint8_t symData[sizeof(macho_nlist<P>)];
+ memcpy(&symData, &sym, sizeof(sym));
+ new_linkedit_data.insert(new_linkedit_data.end(), &symData[0], &symData[sizeof(macho_nlist<P>)]);
+ }
+
+ const uint64_t newIndSymTabOffset = new_linkedit_data.size();
+
+ // Copy indirect symbol table
+ const uint32_t* mergedIndSymTab = (uint32_t*)((char*)mapped_cache + dynamicSymTab->indirectsymoff());
+ new_linkedit_data.insert(new_linkedit_data.end(),
+ (char*)mergedIndSymTab,
+ (char*)(mergedIndSymTab + dynamicSymTab->nindirectsyms()));
+
+ const uint64_t newStringPoolOffset = new_linkedit_data.size();
+
+ // pointer align string pool size
+ while (newSymNames.size() % sizeof(pint_t))
+ newSymNames.push_back('\0');
+
+ new_linkedit_data.insert(new_linkedit_data.end(), newSymNames.begin(), newSymNames.end());
+
+ // update load commands
+ if ( functionStarts != NULL ) {
+ functionStarts->set_dataoff((uint32_t)(newFunctionStartsOffset + linkEditSegCmd->fileoff()));
+ functionStarts->set_datasize(functionStartsSize);
+ }
+ if ( dataInCode != NULL ) {
+ dataInCode->set_dataoff((uint32_t)(newDataInCodeOffset + linkEditSegCmd->fileoff()));
+ dataInCode->set_datasize(dataInCodeSize);
+ }
+
+ symtab->set_nsyms(newSymCount);
+ symtab->set_symoff((uint32_t)(newSymTabOffset + linkEditSegCmd->fileoff()));
+ symtab->set_stroff((uint32_t)(newStringPoolOffset + linkEditSegCmd->fileoff()));
+ symtab->set_strsize((uint32_t)newSymNames.size());
+ dynamicSymTab->set_extreloff(0);
+ dynamicSymTab->set_nextrel(0);
+ dynamicSymTab->set_locreloff(0);
+ dynamicSymTab->set_nlocrel(0);
+ dynamicSymTab->set_indirectsymoff((uint32_t)(newIndSymTabOffset + linkEditSegCmd->fileoff()));
+ linkEditSegCmd->set_filesize(symtab->stroff()+symtab->strsize() - linkEditSegCmd->fileoff());
+ linkEditSegCmd->set_vmsize( (linkEditSegCmd->filesize()+4095) & (-4096) );
+
+ // <rdar://problem/17671438> Xcode 6 leaks in dyld_shared_cache_extract_dylibs
+ for (std::vector<mach_o::trie::Entry>::iterator it = exports.begin(); it != exports.end(); ++it) {
+ ::free((void*)(it->name));
+ }
+
+
+ return 0;
+ }
+
+};
+
+static void make_dirs(const char* file_path)
+{
+ //printf("make_dirs(%s)\n", file_path);
+ char dirs[strlen(file_path)+1];
+ strcpy(dirs, file_path);
+ char* lastSlash = strrchr(dirs, '/');
+ if ( lastSlash == NULL )
+ return;
+ lastSlash[1] = '\0';
+ struct stat stat_buf;
+ if ( stat(dirs, &stat_buf) != 0 ) {
+ char* afterSlash = &dirs[1];
+ char* slash;
+ while ( (slash = strchr(afterSlash, '/')) != NULL ) {
+ *slash = '\0';
+ ::mkdir(dirs, S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH);
+ //printf("mkdir(%s)\n", dirs);
+ *slash = '/';
+ afterSlash = slash+1;
+ }
+ }
+}
+
+
+
+template <typename A>
+void dylib_maker(const void* mapped_cache, std::vector<uint8_t> &dylib_data, const std::vector<seg_info>& segments) {
+ typedef typename A::P P;
+
+ size_t additionalSize = 0;
+ for(std::vector<seg_info>::const_iterator it=segments.begin(); it != segments.end(); ++it) {
+ if ( strcmp(it->segName, "__LINKEDIT") != 0 )
+ additionalSize += it->sizem;
+ }
+
+ std::vector<uint8_t> new_dylib_data;
+ new_dylib_data.reserve(additionalSize);
+
+ // Write regular segments into the buffer
+ uint64_t textOffsetInCache = 0;
+ for( std::vector<seg_info>::const_iterator it=segments.begin(); it != segments.end(); ++it) {
+
+ if(strcmp(it->segName, "__TEXT") == 0 )
+ textOffsetInCache = it->offset;
+
+ //printf("segName=%s, offset=0x%llX, size=0x%0llX\n", it->segName, it->offset, it->sizem);
+ // Copy all but the __LINKEDIT. It will be copied later during the optimizer in to a temporary buffer but it would
+ // not be efficient to copy it all now for each dylib.
+ if (strcmp(it->segName, "__LINKEDIT") == 0 )
+ continue;
+ std::copy(((uint8_t*)mapped_cache)+it->offset, ((uint8_t*)mapped_cache)+it->offset+it->sizem, std::back_inserter(new_dylib_data));
+ }
+
+ // optimize linkedit
+ std::vector<uint8_t> new_linkedit_data;
+ new_linkedit_data.reserve(1 << 20);
+
+ LinkeditOptimizer<A> linkeditOptimizer;
+ macho_header<P>* mh = (macho_header<P>*)&new_dylib_data.front();
+ linkeditOptimizer.optimize_loadcommands(mh);
+ linkeditOptimizer.optimize_linkedit(new_linkedit_data, textOffsetInCache, mapped_cache);
+
+ new_dylib_data.insert(new_dylib_data.end(), new_linkedit_data.begin(), new_linkedit_data.end());
+
+ // Page align file
+ while (new_dylib_data.size() % 4096)
+ new_dylib_data.push_back(0);
+
+ dylib_data.insert(dylib_data.end(), new_dylib_data.begin(), new_dylib_data.end());
+}
+
+typedef __typeof(dylib_maker<x86>) dylib_maker_func;
+typedef void (^progress_block)(unsigned current, unsigned total);
+
+class SharedCacheExtractor;
+struct SharedCacheDylibExtractor {
+ SharedCacheDylibExtractor(const char* name, std::vector<seg_info> segInfo)
+ : name(name), segInfo(segInfo) { }
+
+ void extractCache(SharedCacheExtractor& context);
+
+ const char* name;
+ const std::vector<seg_info> segInfo;
+ int result = 0;
+};
+
+struct SharedCacheExtractor {
+ SharedCacheExtractor(const NameToSegments& map,
+ const char* extraction_root_path,
+ dylib_maker_func* dylib_create_func,
+ void* mapped_cache,
+ progress_block progress)
+ : map(map), extraction_root_path(extraction_root_path),
+ dylib_create_func(dylib_create_func), mapped_cache(mapped_cache),
+ progress(progress) {
+
+ extractors.reserve(map.size());
+ for (auto it : map)
+ extractors.emplace_back(it.first, it.second);
+
+ // Limit the number of open files. 16 seems to give better performance than higher numbers.
+ sema = dispatch_semaphore_create(16);
+ }
+ int extractCaches();
+
+ static void extractCache(void *ctx, size_t i);
+
+ const NameToSegments& map;
+ std::vector<SharedCacheDylibExtractor> extractors;
+ dispatch_semaphore_t sema;
+ const char* extraction_root_path;
+ dylib_maker_func* dylib_create_func;
+ void* mapped_cache;
+ progress_block progress;
+ std::atomic_int count = { 0 };
+};
+
+int SharedCacheExtractor::extractCaches() {
+ dispatch_queue_t process_queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0);
+ dispatch_apply_f(map.size(), process_queue,
+ this, extractCache);
+
+ int result = 0;
+ for (const SharedCacheDylibExtractor& extractor : extractors) {
+ if (extractor.result != 0) {
+ result = extractor.result;
+ break;
+ }
+ }
+ return result;
+}
+
+void SharedCacheExtractor::extractCache(void *ctx, size_t i) {
+ SharedCacheExtractor& context = *(SharedCacheExtractor*)ctx;
+ dispatch_semaphore_wait(context.sema, DISPATCH_TIME_FOREVER);
+ context.extractors[i].extractCache(context);
+ dispatch_semaphore_signal(context.sema);
+}
+
+void SharedCacheDylibExtractor::extractCache(SharedCacheExtractor &context) {
+
+ char dylib_path[PATH_MAX];
+ strcpy(dylib_path, context.extraction_root_path);
+ strcat(dylib_path, "/");
+ strcat(dylib_path, name);
+
+ //printf("%s with %lu segments\n", dylib_path, it->second.size());
+ // make sure all directories in this path exist
+ make_dirs(dylib_path);
+
+ // open file, create if does not already exist
+ int fd = ::open(dylib_path, O_CREAT | O_TRUNC | O_EXLOCK | O_RDWR, 0644);
+ if ( fd == -1 ) {
+ fprintf(stderr, "can't open or create dylib file %s, errnor=%d\n", dylib_path, errno);
+ result = -1;
+ return;
+ }
+
+ std::vector<uint8_t> vec;
+ context.dylib_create_func(context.mapped_cache, vec, segInfo);
+ context.progress(context.count++, (unsigned)context.map.size());
+
+ // Write file data
+ if( write(fd, &vec.front(), vec.size()) == -1) {
+ fprintf(stderr, "error writing, errnor=%d\n", errno);
+ result = -1;
+ }
+
+ close(fd);
+}
+
+static int sharedCacheIsValid(const void* mapped_cache, uint64_t size) {
+ // First check that the size is good.
+ // Note the shared cache may not have a codeSignatureSize value set so we need to first make
+ // sure we have space for the CS_SuperBlob, then later crack that to check for the size of the rest.
+ const DyldSharedCache* dyldSharedCache = (DyldSharedCache*)mapped_cache;
+ uint64_t requiredSizeForCSSuperBlob = dyldSharedCache->header.codeSignatureOffset + sizeof(CS_SuperBlob);
+ const dyld_cache_mapping_info* mappings = (dyld_cache_mapping_info*)((uint8_t*)mapped_cache + dyldSharedCache->header.mappingOffset);
+ if ( requiredSizeForCSSuperBlob > size ) {
+ fprintf(stderr, "Error: dyld shared cache size 0x%08llx is less than required size of 0x%08llx.\n", size, requiredSizeForCSSuperBlob);
+ return -1;
+ }
+
+ // Now see if the code signatures are valid as that tells us the pages aren't corrupt.
+ // First find all of the regions of the shared cache we computed cd hashes
+ std::vector<std::pair<uint64_t, uint64_t>> sharedCacheRegions;
+ sharedCacheRegions.emplace_back(std::make_pair(mappings[0].fileOffset, mappings[0].fileOffset + mappings[0].size));
+ sharedCacheRegions.emplace_back(std::make_pair(mappings[1].fileOffset, mappings[1].fileOffset + mappings[1].size));
+ sharedCacheRegions.emplace_back(std::make_pair(mappings[2].fileOffset, mappings[2].fileOffset + mappings[2].size));
+ if (dyldSharedCache->header.localSymbolsSize)
+ sharedCacheRegions.emplace_back(std::make_pair(dyldSharedCache->header.localSymbolsOffset, dyldSharedCache->header.localSymbolsOffset + dyldSharedCache->header.localSymbolsSize));
+ size_t inBbufferSize = 0;
+ for (auto& sharedCacheRegion : sharedCacheRegions)
+ inBbufferSize += (sharedCacheRegion.second - sharedCacheRegion.first);
+
+ // Now take the cd hash from the cache itself and validate the regions we found.
+ uint8_t* codeSignatureRegion = (uint8_t*)mapped_cache + dyldSharedCache->header.codeSignatureOffset;
+ CS_SuperBlob* sb = reinterpret_cast<CS_SuperBlob*>(codeSignatureRegion);
+ if (sb->magic != htonl(CSMAGIC_EMBEDDED_SIGNATURE)) {
+ fprintf(stderr, "Error: dyld shared cache code signature magic is incorrect.\n");
+ return -1;
+ }
+
+ size_t sbSize = ntohl(sb->length);
+ uint64_t requiredSizeForCS = dyldSharedCache->header.codeSignatureOffset + sbSize;
+ if ( requiredSizeForCS > size ) {
+ fprintf(stderr, "Error: dyld shared cache size 0x%08llx is less than required size of 0x%08llx.\n", size, requiredSizeForCS);
+ return -1;
+ }
+
+ // Find the offset to the code directory.
+ CS_CodeDirectory* cd = nullptr;
+ for (unsigned i =0; i != sb->count; ++i) {
+ if (ntohl(sb->index[i].type) == CSSLOT_CODEDIRECTORY) {
+ cd = (CS_CodeDirectory*)(codeSignatureRegion + ntohl(sb->index[i].offset));
+ break;
+ }
+ }
+
+ if (!cd) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory is missing.\n");
+ return -1;
+ }
+
+ if ( (uint8_t*)cd > (codeSignatureRegion + sbSize) ) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory is out of bounds.\n");
+ return -1;
+ }
+
+ if ( cd->magic != htonl(CSMAGIC_CODEDIRECTORY) ) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory magic is incorrect.\n");
+ return -1;
+ }
+
+ uint32_t pageSize = 1 << cd->pageSize;
+ uint32_t slotCountFromRegions = (uint32_t)((inBbufferSize + pageSize - 1) / pageSize);
+ if ( ntohl(cd->nCodeSlots) < slotCountFromRegions ) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory num slots is incorrect.\n");
+ return -1;
+ }
+
+ uint32_t dscDigestFormat = kCCDigestNone;
+ switch (cd->hashType) {
+ case CS_HASHTYPE_SHA1:
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+ dscDigestFormat = kCCDigestSHA1;
+#pragma clang diagnostic pop
+ break;
+ case CS_HASHTYPE_SHA256:
+ dscDigestFormat = kCCDigestSHA256;
+ break;
+ default:
+ break;
+ }
+
+ if (dscDigestFormat != kCCDigestNone) {
+ const uint64_t csPageSize = 1 << cd->pageSize;
+ size_t hashOffset = ntohl(cd->hashOffset);
+ uint8_t* hashSlot = (uint8_t*)cd + hashOffset;
+ uint8_t cdHashBuffer[cd->hashSize];
+
+ // Skip local symbols for now as those aren't being codesign correctly right now.
+ size_t inBbufferSize = 0;
+ for (auto& sharedCacheRegion : sharedCacheRegions) {
+ if (sharedCacheRegion.first == dyldSharedCache->header.localSymbolsOffset)
+ continue;
+ inBbufferSize += (sharedCacheRegion.second - sharedCacheRegion.first);
+ }
+ uint32_t slotCountToProcess = (uint32_t)((inBbufferSize + pageSize - 1) / pageSize);
+
+ for (unsigned i = 0; i != slotCountToProcess; ++i) {
+ // Skip data pages as those may have been slid by ASLR in the extracted file
+ uint64_t fileOffset = i * csPageSize;
+ if ( (fileOffset >= mappings[1].fileOffset) && (fileOffset < (mappings[1].fileOffset + mappings[1].size)) )
+ continue;
+
+ CCDigest(dscDigestFormat, (uint8_t*)mapped_cache + fileOffset, (size_t)csPageSize, cdHashBuffer);
+ uint8_t* cacheCdHashBuffer = hashSlot + (i * cd->hashSize);
+ if (memcmp(cdHashBuffer, cacheCdHashBuffer, cd->hashSize) != 0) {
+ fprintf(stderr, "Error: dyld shared cache code signature for page %d is incorrect.\n", i);
+ return -1;
+ }
+ }
+ }
+ return 0;
+}
+
+int dyld_shared_cache_extract_dylibs_progress(const char* shared_cache_file_path, const char* extraction_root_path,
+ progress_block progress)
+{
+ struct stat statbuf;
+ if (stat(shared_cache_file_path, &statbuf)) {
+ fprintf(stderr, "Error: stat failed for dyld shared cache at %s\n", shared_cache_file_path);
+ return -1;
+ }
+
+ int cache_fd = open(shared_cache_file_path, O_RDONLY);
+ if (cache_fd < 0) {
+ fprintf(stderr, "Error: failed to open shared cache file at %s\n", shared_cache_file_path);
+ return -1;
+ }
+
+ void* mapped_cache = mmap(NULL, (size_t)statbuf.st_size, PROT_READ, MAP_PRIVATE, cache_fd, 0);
+ if (mapped_cache == MAP_FAILED) {
+ fprintf(stderr, "Error: mmap() for shared cache at %s failed, errno=%d\n", shared_cache_file_path, errno);
+ return -1;
+ }
+
+ close(cache_fd);
+
+ // instantiate arch specific dylib maker
+ dylib_maker_func* dylib_create_func = nullptr;
+ if ( strcmp((char*)mapped_cache, "dyld_v1 i386") == 0 )
+ dylib_create_func = dylib_maker<x86>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 x86_64") == 0 )
+ dylib_create_func = dylib_maker<x86_64>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 x86_64h") == 0 )
+ dylib_create_func = dylib_maker<x86_64>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 armv5") == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 armv6") == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 armv7") == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strncmp((char*)mapped_cache, "dyld_v1 armv7", 14) == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 arm64") == 0 )
+ dylib_create_func = dylib_maker<arm64>;
+#if SUPPORT_ARCH_arm64e
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 arm64e") == 0 )
+ dylib_create_func = dylib_maker<arm64>;
+#endif
+#if SUPPORT_ARCH_arm64_32
+ else if ( strcmp((char*)mapped_cache, "dyld_v1arm64_32") == 0 )
+ dylib_create_func = dylib_maker<arm64_32>;
+#endif
+ else {
+ fprintf(stderr, "Error: unrecognized dyld shared cache magic.\n");
+ munmap(mapped_cache, (size_t)statbuf.st_size);
+ return -1;
+ }
+
+ // Verify that the cache isn't corrupt.
+ if (int result = sharedCacheIsValid(mapped_cache, (uint64_t)statbuf.st_size)) {
+ munmap(mapped_cache, (size_t)statbuf.st_size);
+ return result;
+ }
+
+ // iterate through all images in cache and build map of dylibs and segments
+ __block NameToSegments map;
+ int result = 0;
+
+ result = dyld_shared_cache_iterate(mapped_cache, (uint32_t)statbuf.st_size, ^(const dyld_shared_cache_dylib_info* dylibInfo, const dyld_shared_cache_segment_info* segInfo) {
+ map[dylibInfo->path].push_back(seg_info(segInfo->name, segInfo->fileOffset, segInfo->fileSize));
+ });
+
+ if(result != 0) {
+ fprintf(stderr, "Error: dyld_shared_cache_iterate_segments_with_slide failed.\n");
+ munmap(mapped_cache, (size_t)statbuf.st_size);
+ return result;
+ }
+
+ // for each dylib instantiate a dylib file
+ SharedCacheExtractor extractor(map, extraction_root_path, dylib_create_func, mapped_cache, progress);
+ result = extractor.extractCaches();
+
+ munmap(mapped_cache, (size_t)statbuf.st_size);
+ return result;
+}
+
+
+
+int dyld_shared_cache_extract_dylibs(const char* shared_cache_file_path, const char* extraction_root_path)
+{
+ return dyld_shared_cache_extract_dylibs_progress(shared_cache_file_path, extraction_root_path,
+ ^(unsigned , unsigned) {} );
+}
+
+
+#if 0
+// test program
+#include <stdio.h>
+#include <stddef.h>
+#include <dlfcn.h>
+
+
+typedef int (*extractor_proc)(const char* shared_cache_file_path, const char* extraction_root_path,
+ void (^progress)(unsigned current, unsigned total));
+
+int main(int argc, const char* argv[])
+{
+ if ( argc != 3 ) {
+ fprintf(stderr, "usage: dsc_extractor <path-to-cache-file> <path-to-device-dir>\n");
+ return 1;
+ }
+
+ //void* handle = dlopen("/Volumes/my/src/dyld/build/Debug/dsc_extractor.bundle", RTLD_LAZY);
+ void* handle = dlopen("/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/usr/lib/dsc_extractor.bundle", RTLD_LAZY);
+ if ( handle == NULL ) {
+ fprintf(stderr, "dsc_extractor.bundle could not be loaded\n");
+ return 1;
+ }
+
+ extractor_proc proc = (extractor_proc)dlsym(handle, "dyld_shared_cache_extract_dylibs_progress");
+ if ( proc == NULL ) {
+ fprintf(stderr, "dsc_extractor.bundle did not have dyld_shared_cache_extract_dylibs_progress symbol\n");
+ return 1;
+ }
+
+ int result = (*proc)(argv[1], argv[2], ^(unsigned c, unsigned total) { printf("%d/%d\n", c, total); } );
+ fprintf(stderr, "dyld_shared_cache_extract_dylibs_progress() => %d\n", result);
+ return 0;
+}
+
+
+#endif
+
+
+
+