| #include "modules.h"␊ |
| ␊ |
| ␊ |
| moduleList_t* loadedModules = NULL;␊ |
| symbolList_t* moduleSymbols = NULL;␊ |
| unsigned int (*lookup_symbol)(const char*) = NULL;␊ |
| ␊ |
| ␊ |
|
| ␊ |
| int load_module(const char* module)␊ |
| {␊ |
| ␉// Check to see if the module has already been loaded␊ |
| ␉if(is_module_laoded(module))␊ |
| ␉{␊ |
| ␉␉printf("Module %s already loaded\n");␊ |
| ␉␉return 1;␊ |
| ␉}␊ |
| ␉␊ |
| ␉char modString[128];␊ |
| ␉int fh = -1;␊ |
| ␉sprintf(modString, "/Extra/modules/%s.dylib", module);␊ |
|
| ␊ |
| void* parse_mach(void* binary)␊ |
| {␊ |
| ␉int (*module_init)(void) = NULL;␊ |
| ␉void (*module_start)(void) = NULL;␊ |
| ␊ |
| ␊ |
|
| ␉␊ |
| ␉char* symbolStub = NULL;␊ |
| ␉char* nonlazy = NULL;␊ |
| ␉char* nonlazy_variables = NULL;␊ |
| ␉//char* nonlazy_variables = NULL;␊ |
| ␊ |
| ␉char* symbolTable = NULL;␊ |
| ␉// TODO convert all of the structs a union␊ |
| ␉struct load_command *loadCommand;␊ |
| ␉struct dylib_command* dylibCommand;␊ |
| ␉struct dyld_info_command* dyldInfoCommand;␊ |
| ␉struct symtab_command* symtabCommand;␊ |
| ␉struct segment_command* segmentCommand;␊ |
| ␉struct dysymtab_command* dysymtabCommand;␊ |
| ␉struct section* section;␊ |
| ␉struct load_command *loadCommand = NULL;␊ |
| ␉struct dylib_command* dylibCommand = NULL;␊ |
| ␉struct dyld_info_command* dyldInfoCommand = NULL;␊ |
| ␉struct symtab_command* symtabCommand = NULL;␊ |
| ␉struct segment_command* segmentCommand = NULL;␊ |
| ␉struct dysymtab_command* dysymtabCommand = NULL;␊ |
| ␉struct section* section = NULL;␊ |
| ␉UInt32 binaryIndex = sizeof(struct mach_header);␊ |
| ␉UInt16 cmd = 0;␊ |
| ␊ |
|
| ␉␉{␊ |
| ␉␉␉case LC_SYMTAB:␊ |
| ␉␉␉␉symtabCommand = binary + binaryIndex;␊ |
| ␊ |
| ␉␉␉␉UInt32 symbolIndex = 0;␊ |
| ␉␉␉␉char* symbolString = (UInt32)binary + (char*)symtabCommand->stroff;␊ |
| ␉␉␉␉symbolTable = binary + symtabCommand->symoff;␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉int externalIndex = 0;␊ |
| ␉␉␉␉while(symbolIndex < symtabCommand->nsyms)␊ |
| ␉␉␉␉{␊ |
| ␉␉␉␉␉␊ |
| ␉␉␉␉␉struct nlist* symbolEntry = binary + symtabCommand->symoff + (symbolIndex * sizeof(struct nlist));␊ |
| ␉␉␉␉␉␊ |
| ␉␉␉␉␉// If the symbol is exported by this module␊ |
| ␉␉␉␉␉if(symbolEntry->n_value)␊ |
| ␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉if(strcmp(symbolString + symbolEntry->n_un.n_strx, "_start") == 0)␊ |
| ␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉// Module init located. Don't register it, only called once␊ |
| ␉␉␉␉␉␉␉module_init = binary + symbolEntry->n_value;␊ |
| ␉␉␉␉␉␉}␊ |
| ␉␉␉␉␉␉else if(strcmp(symbolString + symbolEntry->n_un.n_strx, "start") == 0)␊ |
| ␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉// Module start located. Start is an alias so don't register it␊ |
| ␉␉␉␉␉␉␉module_start = binary + symbolEntry->n_value;␊ |
| ␉␉␉␉␉␉}␊ |
| ␉␉␉␉␉␉else␊ |
| ␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉add_symbol(symbolString + symbolEntry->n_un.n_strx, binary + symbolEntry->n_value); ␊ |
| ␉␉␉␉␉␉}␊ |
| ␉␉␉␉␉}␊ |
| ␉␉␉␉␉// External symbol␊ |
| ␉␉␉␉␉else if(symbolEntry->n_type & 0x01 && symbolStub)␊ |
| ␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉printf("Located external symbol %s", symbolString + symbolEntry->n_un.n_strx);␊ |
| ␉␉␉␉␉␉printf(" stub at 0x%X, (0x%X)\n", symbolStub + STUB_ENTRY_SIZE * externalIndex - (UInt32)binary, symbolStub + STUB_ENTRY_SIZE * externalIndex);␊ |
| ␉␉␉␉␉␉getc();␊ |
| ␉␉␉␉␉␉// Patch stub␊ |
| ␉␉␉␉␉␉if(lookup_symbol == NULL)␊ |
| ␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉printf("Symbol.dylib not loaded. Module loader not setup.\n");␊ |
| ␉␉␉␉␉␉␉return NULL;␊ |
| ␉␉␉␉␉␉}␊ |
| ␉␉␉␉␉␉else␊ |
| ␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉void* symbolAddress = (void*)lookup_symbol(symbolString + symbolEntry->n_un.n_strx);␊ |
| ␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉if((0xFFFFFFFF == (UInt32)symbolAddress) && ␊ |
| ␉␉␉␉␉␉␉ strcmp(symbolString + symbolEntry->n_un.n_strx, SYMBOL_DYLD_STUB_BINDER) != 0)␊ |
| ␉␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉␉printf("Unable to locate symbol %s\n", symbolString + symbolEntry->n_un.n_strx);␊ |
| ␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉}␊ |
| ␉␉␉␉␉␉␉else ␊ |
| ␉␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉␉char* patchLocation = symbolStub + STUB_ENTRY_SIZE * externalIndex;␊ |
| ␉␉␉␉␉␉␉␉//patch with far jump ;␊ |
| ␉␉␉␉␉␉␉␉/*␊ |
| ␉␉␉␉␉␉␉␉printf("0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ␊ |
| ␉␉␉␉␉␉␉␉␉ patchLocation[0],␊ |
| ␉␉␉␉␉␉␉␉␉ patchLocation[1],␊ |
| ␉␉␉␉␉␉␉␉␉ patchLocation[2],␊ |
| ␉␉␉␉␉␉␉␉␉ patchLocation[3],␊ |
| ␉␉␉␉␉␉␉␉␉ patchLocation[4],␊ |
| ␉␉␉␉␉␉␉␉␉ patchLocation[5]);␊ |
| ␉␉␉␉␉␉␉␉*/␊ |
| ␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉␉// Point the symbol stub to the nonlazy pointers␊ |
| ␉␉␉␉␉␉␉␉patchLocation[0] = 0xFF;␉// Should already be this␊ |
| ␉␉␉␉␉␉␉␉patchLocation[1] = 0x25;␉// Should already be this␊ |
| ␉␉␉␉␉␉␉␉patchLocation[2] = ((UInt32)(nonlazy + externalIndex * 4) & 0x000000FF) >> 0;␊ |
| ␉␉␉␉␉␉␉␉patchLocation[3] = ((UInt32)(nonlazy + externalIndex * 4) & 0x0000FF00) >> 8;␊ |
| ␉␉␉␉␉␉␉␉patchLocation[4] = ((UInt32)(nonlazy + externalIndex * 4) & 0x00FF0000) >> 16;␊ |
| ␉␉␉␉␉␉␉␉patchLocation[5] = ((UInt32)(nonlazy + externalIndex * 4) & 0xFF000000) >> 24;␊ |
| ␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉␉// Set the nonlazy pointer to the correct address␊ |
| ␉␉␉␉␉␉␉␉patchLocation = (nonlazy + externalIndex*4);␊ |
| ␉␉␉␉␉␉␉␉patchLocation[0] =((UInt32)symbolAddress & 0x000000FF) >> 0;␊ |
| ␉␉␉␉␉␉␉␉patchLocation[1] =((UInt32)symbolAddress & 0x0000FF00) >> 8;␊ |
| ␉␉␉␉␉␉␉␉patchLocation[2] =((UInt32)symbolAddress & 0x00FF0000) >> 16;␊ |
| ␉␉␉␉␉␉␉␉patchLocation[3] =((UInt32)symbolAddress & 0xFF000000) >> 24;␊ |
| ␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉␉externalIndex++;␊ |
| ␊ |
| ␉␉␉␉␉␉␉}␊ |
| ␊ |
| ␉␉␉␉␉␉␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉}␊ |
| ␉␉␉␉␉␉␉␉␉␉␉ ␊ |
| ␉␉␉␉␉}␊ |
| ␊ |
| ␉␉␉␉␉symbolEntry+= sizeof(struct nlist);␊ |
| ␉␉␉␉␉symbolIndex++;␉// TODO remove␊ |
| ␉␉␉␉}␊ |
| ␉␉␉␉break;␊ |
| ␊ |
| ␉␉␉case LC_SEGMENT:␊ |
| ␉␉␉␉segmentCommand = binary + binaryIndex;␊ |
| ␊ |
|
| ␉␉␉␉while(sections)␊ |
| ␉␉␉␉{␊ |
| ␉␉␉␉␉// Look for the __symbol_stub section␊ |
| ␉␉␉␉␉if(strcmp(section->sectname, "__nl_symbol_ptr") == 0)␊ |
| ␉␉␉␉␉if(strcmp(section->sectname, SECT_NON_LAZY_SYMBOL_PTR) == 0)␊ |
| ␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉/*printf("\tSection non lazy pointers at 0x%X, %d symbols\n",␊ |
| ␉␉␉␉␉␉␉ section->offset, ␊ |
|
| ␉␉␉␉␉␉switch(section->flags)␊ |
| ␉␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉␉case S_NON_LAZY_SYMBOL_POINTERS:␊ |
| ␉␉␉␉␉␉␉␉nonlazy_variables = binary + section->offset;␊ |
| ␉␉␉␉␉␉␉␉␉break;␊ |
| ␉␉␉␉␉␉␉␉//nonlazy_variables = binary + section->offset;␊ |
| ␉␉␉␉␉␉␉␉break;␊ |
| ␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉case S_LAZY_SYMBOL_POINTERS:␊ |
| ␉␉␉␉␉␉␉␉nonlazy = binary + section->offset;␊ |
|
| ␉␉␉␉␉␉␉␉break;␊ |
| ␉␉␉␉␉␉␉␉␊ |
| ␉␉␉␉␉␉␉default:␊ |
| ␉␉␉␉␉␉␉␉printf("Unhandled __nl_symbol_ptr section\n");␊ |
| ␉␉␉␉␉␉␉␉printf("Unhandled %s section\n", SECT_NON_LAZY_SYMBOL_PTR);␊ |
| ␉␉␉␉␉␉␉␉getc();␊ |
| ␉␉␉␉␉␉␉␉break;␊ |
| ␉␉␉␉␉␉}␊ |
| ␉␉␉␉␉␉//getc();␊ |
| ␉␉␉␉␉}␊ |
| ␉␉␉␉␉else if(strcmp(section->sectname, "__symbol_stub") == 0)␊ |
| ␉␉␉␉␉else if(strcmp(section->sectname, SECT_SYMBOL_STUBS) == 0)␊ |
| ␉␉␉␉␉{␊ |
| ␉␉␉␉␉␉/*printf("\tSection __symbol_stub at 0x%X (0x%X), %d symbols\n",␊ |
| ␉␉␉␉␉␉␉ section->offset, ␊ |
|
| ␉␉␉␉break;␊ |
| ␉␉␉␉␊ |
| ␉␉␉case LC_LOAD_DYLIB:␊ |
| ␉␉␉␉//printf("Unhandled loadcommand LC_LOAD_DYLIB\n");␊ |
| ␉␉␉case LC_LOAD_WEAK_DYLIB:␊ |
| ␉␉␉{␊ |
| ␉␉␉␉// TODO: do this before ␊ |
| ␉␉␉␉struct dylib_command* weakLoad = binary + binaryIndex;␊ |
| ␉␉␉␉load_module((char*)((UInt32)*((UInt32*)&weakLoad->dylib.name)));␊ |
| ␉␉␉}␊ |
| ␉␉␉␉break;␊ |
| ␉␉␉␉␊ |
| ␉␉␉case LC_ID_DYLIB:␊ |
|
| ␉␉␉␉␉ dyldInfoCommand->lazy_bind_off,␊ |
| ␉␉␉␉␉ dyldInfoCommand->export_off);␊ |
| ␉␉␉␉*/␊ |
| ␉␉␉␉if(dyldInfoCommand->bind_off)␊ |
| ␉␉␉␉{␊ |
| ␉␉␉␉␉bind_macho(binary, (char*)dyldInfoCommand->bind_off, dyldInfoCommand->bind_size);␊ |
| ␉␉␉␉}␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉/*␊ |
| ␉␉␉␉ // This is done later on using the __symbol_stub instead␊ |
| ␉␉␉␉if(dyldInfoCommand->lazy_bind_off)␊ |
| ␉␉␉␉{␊ |
| ␉␉␉␉␉bind_macho(binary, (char*)dyldInfoCommand->lazy_bind_off, dyldInfoCommand->lazy_bind_size);␊ |
| ␉␉␉␉␉␊ |
| ␉␉␉␉}*/␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉if(dyldInfoCommand->rebase_off)␊ |
| ␉␉␉␉{␊ |
| ␉␉␉␉␉rebase_macho(binary, (char*)dyldInfoCommand->rebase_off, dyldInfoCommand->rebase_size);␊ |
| ␉␉␉␉}␊ |
| ␉␉␉␉break;␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉break;␊ |
| ␊ |
| ␉␉␉case LC_UUID:␊ |
| ␉␉␉␉// We don't care about the UUID at the moment␊ |
| ␉␉␉␉break;␊ |
|
| ␉␉binaryIndex += cmdSize;␊ |
| ␉}␊ |
| ␉if(!moduleName) return NULL;␊ |
| ␉␉␊ |
| ␉␊ |
| ␉// Module is loaded and all module dependencies have been loaded, bind the module␊ |
| ␉// NOTE: circular dependencies are not handled yet␊ |
| ␉if(dyldInfoCommand && dyldInfoCommand->bind_off)␊ |
| ␉{␊ |
| ␉␉bind_macho(binary, (char*)dyldInfoCommand->bind_off, dyldInfoCommand->bind_size);␊ |
| ␉}␊ |
| ␉␊ |
| ␉// TODO: Initialize the module.␊ |
| ␉printf("Calling _start\n");␊ |
| ␉if(dyldInfoCommand && dyldInfoCommand->rebase_off)␊ |
| ␉{␊ |
| ␉␉rebase_macho(binary, (char*)dyldInfoCommand->rebase_off, dyldInfoCommand->rebase_size);␊ |
| ␉}␊ |
| ␉␊ |
| ␉getc();␊ |
| ␉if(module_init) ␊ |
| ␉{␊ |
| ␉␉jump_pointer(module_init);␊ |
| ␉ }␊ |
| ␉module_start = (void*)handle_symtable((UInt32)binary, symtabCommand, symbolStub, nonlazy);␊ |
| ␊ |
| ␉␊ |
| ␉// To satisfy cicular deps, the module_loaded command shoudl be run before the module init();␊ |
| ␉module_loaded(moduleName, moduleVersion, moduleCompat);␊ |
| ␉getc();␊ |
| ␉ //*/␊ |
| ␉return module_start; // TODO populate w/ address of _start␊ |
| ␉␊ |
| ␉return module_start;␊ |
| ␉␊ |
| }␊ |
| ␊ |
| ␊ |
| // This is for debugging, remove the jump_pointer funciton later␊ |
| int jump_pointer(int (*pointer)())␊ |
| {␊ |
| ␉printf("Jumping to function at 0x%X\n", pointer);␊ |
| ␊ |
| ␉getc();␊ |
| ␉return (*pointer)();␊ |
| }␊ |
| ␊ |
| // Based on code from dylibinfo.cpp and ImageLoaderMachOCompressed.cpp␊ |
| void rebase_macho(void* base, char* rebase_stream, UInt32 size)␊ |
| {␊ |
|
| // however the macho file is 32 bit, so it shouldn't matter too much␊ |
| void bind_macho(void* base, char* bind_stream, UInt32 size)␊ |
| {␉␊ |
| ␉␊ |
| ␉␊ |
| ␉bind_stream += (UInt32)base;␊ |
| ␉␊ |
| ␉UInt8 immediate = 0;␊ |
|
| ␉␊ |
| ␉UInt32 address = 0;␊ |
| ␉␊ |
| ␉SInt32 addend = 0;␊ |
| ␉SInt32 addend = 0;␉␉␉// TODO: handle this␊ |
| ␉SInt32 libraryOrdinal = 0;␊ |
| ␊ |
| ␉const char* symbolName = NULL;␊ |
| ␉UInt8 symboFlags = 0;␊ |
| ␉UInt32 symbolAddr = 0xFFFFFFFF;␊ |
| ␉␊ |
| ␉// Temperary variables␊ |
| ␉UInt8 bits = 0;␊ |
| ␉UInt32 tmp = 0;␊ |
|
| ␉␉␉␉i += strlen((char*)&bind_stream[i]);␊ |
| ␉␉␉␉//printf("BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: %s, 0x%X\n", symbolName, symboFlags);␊ |
| ␊ |
| ␉␉␉␉symbolAddr = lookup_symbol(symbolName);␊ |
| ␉␉␉␉symbolAddr = lookup_external_all(symbolName);␊ |
| ␊ |
| ␉␉␉␉break;␊ |
| ␉␉␉␉␊ |
|
| * TODO: actualy do something... ␊ |
| * possibly change to a pointer and add this to the Symbol module␊ |
| */␊ |
| void add_symbol(const char* symbol, void* addr)␊ |
| void add_symbol(char* symbol, void* addr)␊ |
| {␊ |
| ␉printf("Adding symbol %s at 0x%X\n", symbol, addr);␊ |
| ␉//printf("Adding symbol %s at 0x%X\n", symbol, addr);␊ |
| ␉␊ |
| ␉//hack␊ |
| ␉if(strcmp(symbol, "_lookup_symbol") == 0)␊ |
| ␉{␊ |
| ␉␉printf("Initializing lookup symbol function\n");␊ |
| ␉␉//printf("Initializing lookup symbol function\n");␊ |
| ␉␉lookup_symbol = addr;␊ |
| ␉}␊ |
| ␉else if(!moduleSymbols)␊ |
| ␉{␊ |
| ␉␉moduleSymbols = malloc(sizeof(symbolList_t));␊ |
| ␉␉moduleSymbols->next = NULL;␊ |
| ␉␉moduleSymbols->addr = (unsigned int)addr;␊ |
| ␉␉moduleSymbols->symbol = symbol;␊ |
| ␉}␊ |
| ␉else␊ |
| ␉{␊ |
| ␉␉symbolList_t* entry = moduleSymbols;␊ |
| ␉␉while(entry->next)␊ |
| ␉␉{␊ |
| ␉␉␉entry = entry->next;␊ |
| ␉␉}␊ |
| ␉␉␊ |
| ␉␉entry->next = malloc(sizeof(symbolList_t));␊ |
| ␉␉entry = entry->next;␊ |
| ␉␉␊ |
| ␉␉entry->next = NULL;␊ |
| ␉␉entry->addr = (unsigned int)addr;␊ |
| ␉␉entry->symbol = symbol;␊ |
| ␉␉␊ |
| ␉}␊ |
| ␉␉␉␉␉␉␉ ␊ |
| ␊ |
| }␊ |
| ␊ |
| ␊ |
| /*␊ |
| * print out the information about the loaded module␊ |
| * In the future, add to a list of laoded modules␊ |
| * so that if another module depends on it we don't␊ |
| * try to reload the same module.␊ |
| ␊ |
| */␊ |
| void module_loaded(const char* name, UInt32 version, UInt32 compat)␊ |
| void module_loaded(char* name, UInt32 version, UInt32 compat)␊ |
| {␊ |
| ␉/*␊ |
| ␉printf("\%s.dylib Version %d.%d.%d loaded\n"␊ |
| ␉␉ "\tCompatibility Version: %d.%d.%d\n",␊ |
| ␉␉ name,␊ |
|
| ␉␉ (version >> 0) & 0x00FF,␊ |
| ␉␉ (compat >> 16) & 0xFFFF,␊ |
| ␉␉ (compat >> 8) & 0x00FF,␊ |
| ␉␉ (compat >> 0) & 0x00FF);␉␉␊ |
| ␉␉ (compat >> 0) & 0x00FF);␉␊ |
| ␉*/␊ |
| ␉if(loadedModules == NULL)␊ |
| ␉{␊ |
| ␉␉loadedModules = malloc(sizeof(moduleList_t));␊ |
| ␉␉loadedModules->next = NULL;␊ |
| ␉␉loadedModules->module = name;␊ |
| ␉␉loadedModules->version = version;␊ |
| ␉␉loadedModules->compat = compat;␊ |
| ␉}␊ |
| ␉else␊ |
| ␉{␊ |
| ␉␉moduleList_t* entry = loadedModules;␊ |
| ␉␉while(entry->next)␊ |
| ␉␉{␊ |
| ␉␉␉entry = entry->next;␊ |
| ␉␉}␊ |
| ␉␉␊ |
| ␉␉entry->next = malloc(sizeof(moduleList_t));␊ |
| ␉␉entry = entry->next;␊ |
| ␉␉␊ |
| ␉␉entry->next = NULL;␊ |
| ␉␉entry->module = name;␊ |
| ␉␉entry->version = version;␊ |
| ␉␉entry->compat = compat;␊ |
| ␉}␊ |
| ␊ |
| ␉␊ |
| }␊ |
| ␊ |
| int is_module_laoded(const char* name)␊ |
| {␊ |
| ␉moduleList_t* entry = loadedModules;␊ |
| ␉while(entry)␊ |
| ␉{␊ |
| ␉␉if(strcmp(entry->module, name) == 0)␊ |
| ␉␉{␊ |
| ␉␉␉return 1;␊ |
| ␉␉}␊ |
| ␉␉else␊ |
| ␉␉{␊ |
| ␉␉␉entry = entry->next;␊ |
| ␉␉}␊ |
| ␊ |
| ␉}␊ |
| ␉return 0;␊ |
| }␊ |
| ␊ |
| // Look for symbols using the Smbols moduel function.␊ |
| // If non are found, look through the list of module symbols␊ |
| unsigned int lookup_external_all(const char* name)␊ |
| {␊ |
| ␉unsigned int addr = 0xFFFFFFFF;␊ |
| ␉if(lookup_symbol)␊ |
| ␉{␊ |
| ␉␉addr = lookup_symbol(name);␊ |
| ␉␉if(addr != 0xFFFFFFFF)␊ |
| ␉␉{␊ |
| ␉␉␉return addr;␊ |
| ␉␉}␊ |
| ␉}␊ |
| ␉else␊ |
| ␉{␊ |
| ␉␉printf("Symbol.dylib not loaded. Module loader not setup.\n");␊ |
| ␉␉return 0xFFFFFFFF;␊ |
| ␉}␊ |
| ␊ |
| ␊ |
| ␉␊ |
| ␉symbolList_t* entry = moduleSymbols;␊ |
| ␉while(entry)␊ |
| ␉{␊ |
| ␉␉if(strcmp(entry->symbol, name) == 0)␊ |
| ␉␉{␊ |
| ␉␉␉return entry->addr;␊ |
| ␉␉}␊ |
| ␉␉else␊ |
| ␉␉{␊ |
| ␉␉␉entry = entry->next;␊ |
| ␉␉}␊ |
| ␊ |
| ␉}␊ |
| ␉␊ |
| ␉return 0xFFFFFFFF;␊ |
| }␊ |
| ␊ |
| ␊ |
| /*␊ |
| * parse the symbol table␊ |
| * Lookup any undefined symbols␊ |
| */␊ |
| ␊ |
| unsigned int handle_symtable(UInt32 base, struct symtab_command* symtabCommand, char* symbolStub, char* nonlazy)␊ |
| {␊ |
| ␉unsigned int module_start = 0xFFFFFFFF;␊ |
| ␉␊ |
| ␉UInt32 symbolIndex = 0;␊ |
| ␉char* symbolString = base + (char*)symtabCommand->stroff;␊ |
| ␉//char* symbolTable = base + symtabCommand->symoff;␊ |
| ␉␊ |
| ␉int externalIndex = 0;␊ |
| ␉while(symbolIndex < symtabCommand->nsyms)␊ |
| ␉{␊ |
| ␉␉␊ |
| ␉␉struct nlist* symbolEntry = (void*)base + symtabCommand->symoff + (symbolIndex * sizeof(struct nlist));␊ |
| ␉␉␊ |
| ␉␉// If the symbol is exported by this module␊ |
| ␉␉if(symbolEntry->n_value)␊ |
| ␉␉{␊ |
| ␉␉␉if(strcmp(symbolString + symbolEntry->n_un.n_strx, "start") == 0)␊ |
| ␉␉␉{␊ |
| ␉␉␉␉// Module start located. Start is an alias so don't register it␊ |
| ␉␉␉␉module_start = base + symbolEntry->n_value;␊ |
| ␉␉␉}␊ |
| ␉␉␉else␊ |
| ␉␉␉{␊ |
| ␉␉␉␉add_symbol(symbolString + symbolEntry->n_un.n_strx, (void*)base + symbolEntry->n_value); ␊ |
| ␉␉␉}␊ |
| ␉␉}␊ |
| ␉␉// External symbol␊ |
| ␉␉else if(symbolEntry->n_type & 0x01 && symbolStub)␊ |
| ␉␉{␊ |
| ␉␉␉printf("Located external symbol %s", symbolString + symbolEntry->n_un.n_strx);␊ |
| ␉␉␉printf(" stub at 0x%X, (0x%X)\n", symbolStub + STUB_ENTRY_SIZE * externalIndex - base, symbolStub + STUB_ENTRY_SIZE * externalIndex);␊ |
| ␉␉␉getc();␊ |
| ␉␉␉␊ |
| ␉␉␉// Patch stub␊ |
| ␉␉␉void* symbolAddress = (void*)lookup_external_all(symbolString + symbolEntry->n_un.n_strx);␊ |
| ␉␉␉␊ |
| ␉␉␉if((0xFFFFFFFF == (UInt32)symbolAddress) && ␊ |
| ␉␉␉ strcmp(symbolString + symbolEntry->n_un.n_strx, SYMBOL_DYLD_STUB_BINDER) != 0)␊ |
| ␉␉␉{␊ |
| ␉␉␉␉printf("Unable to locate symbol %s\n", symbolString + symbolEntry->n_un.n_strx);␊ |
| ␉␉␉␉␊ |
| ␉␉␉}␊ |
| ␉␉␉else ␊ |
| ␉␉␉{␊ |
| ␉␉␉␉char* patchLocation = symbolStub + STUB_ENTRY_SIZE * externalIndex;␊ |
| ␉␉␉␉//patch with far jump ;␊ |
| ␉␉␉␉/*␊ |
| ␉␉␉␉ printf("0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ␊ |
| ␉␉␉␉ patchLocation[0],␊ |
| ␉␉␉␉ patchLocation[1],␊ |
| ␉␉␉␉ patchLocation[2],␊ |
| ␉␉␉␉ patchLocation[3],␊ |
| ␉␉␉␉ patchLocation[4],␊ |
| ␉␉␉␉ patchLocation[5]);␊ |
| ␉␉␉␉ */␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉// Point the symbol stub to the nonlazy pointers␊ |
| ␉␉␉␉// TODO: do this *after* each module dep has been laoded.␊ |
| ␉␉␉␉// At the moment, module deps won't work␊ |
| ␉␉␉␉patchLocation[0] = 0xFF;␉// Should already be this␊ |
| ␉␉␉␉patchLocation[1] = 0x25;␉// Should already be this␊ |
| ␉␉␉␉patchLocation[2] = ((UInt32)(nonlazy + externalIndex * 4) & 0x000000FF) >> 0;␊ |
| ␉␉␉␉patchLocation[3] = ((UInt32)(nonlazy + externalIndex * 4) & 0x0000FF00) >> 8;␊ |
| ␉␉␉␉patchLocation[4] = ((UInt32)(nonlazy + externalIndex * 4) & 0x00FF0000) >> 16;␊ |
| ␉␉␉␉patchLocation[5] = ((UInt32)(nonlazy + externalIndex * 4) & 0xFF000000) >> 24;␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉// Set the nonlazy pointer to the correct address␊ |
| ␉␉␉␉patchLocation = (nonlazy + externalIndex*4);␊ |
| ␉␉␉␉patchLocation[0] =((UInt32)symbolAddress & 0x000000FF) >> 0;␊ |
| ␉␉␉␉patchLocation[1] =((UInt32)symbolAddress & 0x0000FF00) >> 8;␊ |
| ␉␉␉␉patchLocation[2] =((UInt32)symbolAddress & 0x00FF0000) >> 16;␊ |
| ␉␉␉␉patchLocation[3] =((UInt32)symbolAddress & 0xFF000000) >> 24;␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉␊ |
| ␉␉␉␉externalIndex++;␊ |
| ␉␉␉␉␊ |
| ␉␉␉}␊ |
| ␉␉}␊ |
| ␉␉␊ |
| ␉␉symbolEntry+= sizeof(struct nlist);␊ |
| ␉␉symbolIndex++;␉// TODO remove␊ |
| ␉}␊ |
| ␉␊ |
| ␉return module_start;␊ |
| ␉␊ |
| } |
