X-Git-Url: https://git.hcoop.net/hcoop/debian/courier-authlib.git/blobdiff_plain/4e60b389634568bcf4cc5009fa37bba3eb381482..940be80e3e40dbbbd84161e1e5ae3abf0b2eadf6:/libltdl/loaders/dyld.c diff --git a/libltdl/loaders/dyld.c b/libltdl/loaders/dyld.c new file mode 100644 index 0000000..b139d6c --- /dev/null +++ b/libltdl/loaders/dyld.c @@ -0,0 +1,511 @@ +/* loader-dyld.c -- dynamic linking on darwin and OS X + + Copyright (C) 1998, 1999, 2000, 2004, 2006, + 2007, 2008 Free Software Foundation, Inc. + Written by Peter O'Gorman, 1998 + + NOTE: The canonical source of this file is maintained with the + GNU Libtool package. Report bugs to bug-libtool@gnu.org. + +GNU Libltdl is free software; you can redistribute it and/or +modify it under the terms of the GNU Lesser General Public +License as published by the Free Software Foundation; either +version 2 of the License, or (at your option) any later version. + +As a special exception to the GNU Lesser General Public License, +if you distribute this file as part of a program or library that +is built using GNU Libtool, you may include this file under the +same distribution terms that you use for the rest of that program. + +GNU Libltdl is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU Lesser General Public License for more details. + +You should have received a copy of the GNU Lesser General Public +License along with GNU Libltdl; see the file COPYING.LIB. If not, a +copy can be downloaded from http://www.gnu.org/licenses/lgpl.html, +or obtained by writing to the Free Software Foundation, Inc., +51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +*/ + +#include "lt__private.h" +#include "lt_dlloader.h" + +/* Use the preprocessor to rename non-static symbols to avoid namespace + collisions when the loader code is statically linked into libltdl. + Use the "_LTX_" prefix so that the symbol addresses can + be fetched from the preloaded symbol list by lt_dlsym(): */ +#define get_vtable dyld_LTX_get_vtable + +LT_BEGIN_C_DECLS +LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data); +LT_END_C_DECLS + + +/* Boilerplate code to set up the vtable for hooking this loader into + libltdl's loader list: */ +static int vl_init (lt_user_data loader_data); +static int vl_exit (lt_user_data loader_data); +static lt_module vm_open (lt_user_data loader_data, const char *filename, + lt_dladvise advise); +static int vm_close (lt_user_data loader_data, lt_module module); +static void * vm_sym (lt_user_data loader_data, lt_module module, + const char *symbolname); + +static lt_dlvtable *vtable = 0; + +/* Return the vtable for this loader, only the name and sym_prefix + attributes (plus the virtual function implementations, obviously) + change between loaders. */ +lt_dlvtable * +get_vtable (lt_user_data loader_data) +{ + if (!vtable) + { + vtable = lt__zalloc (sizeof *vtable); + } + + if (vtable && !vtable->name) + { + vtable->name = "lt_dyld"; + vtable->sym_prefix = "_"; + vtable->dlloader_init = vl_init; + vtable->module_open = vm_open; + vtable->module_close = vm_close; + vtable->find_sym = vm_sym; + vtable->dlloader_exit = vl_exit; + vtable->dlloader_data = loader_data; + vtable->priority = LT_DLLOADER_APPEND; + } + + if (vtable && (vtable->dlloader_data != loader_data)) + { + LT__SETERROR (INIT_LOADER); + return 0; + } + + return vtable; +} + + + +/* --- IMPLEMENTATION --- */ + + +#if defined(HAVE_MACH_O_DYLD_H) +# if !defined(__APPLE_CC__) && !defined(__MWERKS__) && !defined(__private_extern__) + /* Is this correct? Does it still function properly? */ +# define __private_extern__ extern +# endif +# include +#endif + +#include + +/* We have to put some stuff here that isn't in older dyld.h files */ +#if !defined(ENUM_DYLD_BOOL) +# define ENUM_DYLD_BOOL +# undef FALSE +# undef TRUE + enum DYLD_BOOL { + FALSE, + TRUE + }; +#endif +#if !defined(LC_REQ_DYLD) +# define LC_REQ_DYLD 0x80000000 +#endif +#if !defined(LC_LOAD_WEAK_DYLIB) +# define LC_LOAD_WEAK_DYLIB (0x18 | LC_REQ_DYLD) +#endif + +#if !defined(NSADDIMAGE_OPTION_NONE) +# define NSADDIMAGE_OPTION_NONE 0x0 +#endif +#if !defined(NSADDIMAGE_OPTION_RETURN_ON_ERROR) +# define NSADDIMAGE_OPTION_RETURN_ON_ERROR 0x1 +#endif +#if !defined(NSADDIMAGE_OPTION_WITH_SEARCHING) +# define NSADDIMAGE_OPTION_WITH_SEARCHING 0x2 +#endif +#if !defined(NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED) +# define NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED 0x4 +#endif +#if !defined(NSADDIMAGE_OPTION_MATCH_FILENAME_BY_INSTALLNAME) +# define NSADDIMAGE_OPTION_MATCH_FILENAME_BY_INSTALLNAME 0x8 +#endif + +#if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_BIND) +# define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND 0x0 +#endif +#if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW) +# define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW 0x1 +#endif +#if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_FULLY) +# define NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_FULLY 0x2 +#endif +#if !defined(NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR) +# define NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR 0x4 +#endif + +#define LT__SYMLOOKUP_OPTS (NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW \ + | NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR) + +#if defined(__BIG_ENDIAN__) +# define LT__MAGIC MH_MAGIC +#else +# define LT__MAGIC MH_CIGAM +#endif + +#define DYLD__SETMYERROR(errmsg) LT__SETERRORSTR (dylderror (errmsg)) +#define DYLD__SETERROR(errcode) DYLD__SETMYERROR (LT__STRERROR (errcode)) + +typedef struct mach_header mach_header; +typedef struct dylib_command dylib_command; + +static const char *dylderror (const char *errmsg); +static const mach_header *lt__nsmodule_get_header (NSModule module); +static const char *lt__header_get_instnam (const mach_header *mh); +static const mach_header *lt__match_loadedlib (const char *name); +static NSSymbol lt__linkedlib_symbol (const char *symname, const mach_header *mh); + +static const mach_header *(*lt__addimage) (const char *image_name, + unsigned long options) = 0; +static NSSymbol (*lt__image_symbol) (const mach_header *image, + const char *symbolName, + unsigned long options) = 0; +static enum DYLD_BOOL (*lt__image_symbol_p) (const mach_header *image, + const char *symbolName) = 0; +static enum DYLD_BOOL (*lt__module_export) (NSModule module) = 0; + +static int dyld_cannot_close = 0; + + +/* A function called through the vtable when this loader is no + longer needed by the application. */ +static int +vl_exit (lt_user_data LT__UNUSED loader_data) +{ + vtable = NULL; + return 0; +} + +/* A function called through the vtable to initialise this loader. */ +static int +vl_init (lt_user_data loader_data) +{ + int errors = 0; + + if (! dyld_cannot_close) + { + if (!_dyld_present ()) + { + ++errors; + } + else + { + (void) _dyld_func_lookup ("__dyld_NSAddImage", + (unsigned long*) <__addimage); + (void) _dyld_func_lookup ("__dyld_NSLookupSymbolInImage", + (unsigned long*)<__image_symbol); + (void) _dyld_func_lookup ("__dyld_NSIsSymbolNameDefinedInImage", + (unsigned long*) <__image_symbol_p); + (void) _dyld_func_lookup ("__dyld_NSMakePrivateModulePublic", + (unsigned long*) <__module_export); + dyld_cannot_close = lt_dladderror ("can't close a dylib"); + } + } + + return errors; +} + + +/* A function called through the vtable to open a module with this + loader. Returns an opaque representation of the newly opened + module for processing with this loader's other vtable functions. */ +static lt_module +vm_open (lt_user_data loader_data, const char *filename, + lt_dladvise LT__UNUSED advise) +{ + lt_module module = 0; + NSObjectFileImage ofi = 0; + + if (!filename) + { + return (lt_module) -1; + } + + switch (NSCreateObjectFileImageFromFile (filename, &ofi)) + { + case NSObjectFileImageSuccess: + module = NSLinkModule (ofi, filename, NSLINKMODULE_OPTION_RETURN_ON_ERROR + | NSLINKMODULE_OPTION_PRIVATE + | NSLINKMODULE_OPTION_BINDNOW); + NSDestroyObjectFileImage (ofi); + + if (module) + { + lt__module_export (module); + } + break; + + case NSObjectFileImageInappropriateFile: + if (lt__image_symbol_p && lt__image_symbol) + { + module = (lt_module) lt__addimage(filename, + NSADDIMAGE_OPTION_RETURN_ON_ERROR); + } + break; + + case NSObjectFileImageFailure: + case NSObjectFileImageArch: + case NSObjectFileImageFormat: + case NSObjectFileImageAccess: + /*NOWORK*/ + break; + } + + if (!module) + { + DYLD__SETERROR (CANNOT_OPEN); + } + + return module; +} + + +/* A function called through the vtable when a particular module + should be unloaded. */ +static int +vm_close (lt_user_data loader_data, lt_module module) +{ + int errors = 0; + + if (module != (lt_module) -1) + { + const mach_header *mh = (const mach_header *) module; + int flags = 0; + if (mh->magic == LT__MAGIC) + { + lt_dlseterror (dyld_cannot_close); + ++errors; + } + else + { + /* Currently, if a module contains c++ static destructors and it + is unloaded, we get a segfault in atexit(), due to compiler and + dynamic loader differences of opinion, this works around that. */ + if ((const struct section *) NULL != + getsectbynamefromheader (lt__nsmodule_get_header (module), + "__DATA", "__mod_term_func")) + { + flags |= NSUNLINKMODULE_OPTION_KEEP_MEMORY_MAPPED; + } +#if defined(__ppc__) + flags |= NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES; +#endif + if (!NSUnLinkModule (module, flags)) + { + DYLD__SETERROR (CANNOT_CLOSE); + ++errors; + } + } + } + + return errors; +} + +/* A function called through the vtable to get the address of + a symbol loaded from a particular module. */ +static void * +vm_sym (lt_user_data loader_data, lt_module module, const char *name) +{ + NSSymbol *nssym = 0; + const mach_header *mh = (const mach_header *) module; + char saveError[256] = "Symbol not found"; + + if (module == (lt_module) -1) + { + void *address, *unused; + _dyld_lookup_and_bind (name, (unsigned long*) &address, &unused); + return address; + } + + if (mh->magic == LT__MAGIC) + { + if (lt__image_symbol_p && lt__image_symbol) + { + if (lt__image_symbol_p (mh, name)) + { + nssym = lt__image_symbol (mh, name, LT__SYMLOOKUP_OPTS); + } + } + + } + else + { + nssym = NSLookupSymbolInModule (module, name); + } + + if (!nssym) + { + strncpy (saveError, dylderror (LT__STRERROR (SYMBOL_NOT_FOUND)), 255); + saveError[255] = 0; + if (!mh) + { + mh = (mach_header *)lt__nsmodule_get_header (module); + } + nssym = lt__linkedlib_symbol (name, mh); + } + + if (!nssym) + { + LT__SETERRORSTR (saveError); + } + + return nssym ? NSAddressOfSymbol (nssym) : 0; +} + + + + +/* --- HELPER FUNCTIONS --- */ + + +/* Return the dyld error string, or the passed in error string if none. */ +static const char * +dylderror (const char *errmsg) +{ + NSLinkEditErrors ler; + int lerno; + const char *file; + const char *errstr; + + NSLinkEditError (&ler, &lerno, &file, &errstr); + + if (! (errstr && *errstr)) + { + errstr = errmsg; + } + + return errstr; +} + +/* There should probably be an apple dyld api for this. */ +static const mach_header * +lt__nsmodule_get_header (NSModule module) +{ + int i = _dyld_image_count(); + const char *modname = NSNameOfModule (module); + const mach_header *mh = 0; + + if (!modname) + return NULL; + + while (i > 0) + { + --i; + if (strneq (_dyld_get_image_name (i), modname)) + { + mh = _dyld_get_image_header (i); + break; + } + } + + return mh; +} + +/* NSAddImage is also used to get the loaded image, but it only works if + the lib is installed, for uninstalled libs we need to check the + install_names against each other. Note that this is still broken if + DYLD_IMAGE_SUFFIX is set and a different lib was loaded as a result. */ +static const char * +lt__header_get_instnam (const mach_header *mh) +{ + unsigned long offset = sizeof(mach_header); + const char* result = 0; + int j; + + for (j = 0; j < mh->ncmds; j++) + { + struct load_command *lc; + + lc = (struct load_command*) (((unsigned long) mh) + offset); + if (LC_ID_DYLIB == lc->cmd) + { + result=(char*)(((dylib_command*) lc)->dylib.name.offset + + (unsigned long) lc); + } + offset += lc->cmdsize; + } + + return result; +} + +static const mach_header * +lt__match_loadedlib (const char *name) +{ + const mach_header *mh = 0; + int i = _dyld_image_count(); + + while (i > 0) + { + const char *id; + + --i; + id = lt__header_get_instnam (_dyld_get_image_header (i)); + if (id && strneq (id, name)) + { + mh = _dyld_get_image_header (i); + break; + } + } + + return mh; +} + +/* Safe to assume our mh is good. */ +static NSSymbol +lt__linkedlib_symbol (const char *symname, const mach_header *mh) +{ + NSSymbol symbol = 0; + + if (lt__image_symbol && NSIsSymbolNameDefined (symname)) + { + unsigned long offset = sizeof(mach_header); + struct load_command *lc; + int j; + + for (j = 0; j < mh->ncmds; j++) + { + lc = (struct load_command*) (((unsigned long) mh) + offset); + if ((LC_LOAD_DYLIB == lc->cmd) || (LC_LOAD_WEAK_DYLIB == lc->cmd)) + { + unsigned long base = ((dylib_command *) lc)->dylib.name.offset; + char *name = (char *) (base + (unsigned long) lc); + const mach_header *mh1 = lt__match_loadedlib (name); + + if (!mh1) + { + /* Maybe NSAddImage can find it */ + mh1 = lt__addimage (name, + NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED + | NSADDIMAGE_OPTION_WITH_SEARCHING + | NSADDIMAGE_OPTION_RETURN_ON_ERROR); + } + + if (mh1) + { + symbol = lt__image_symbol (mh1, symname, LT__SYMLOOKUP_OPTS); + if (symbol) + break; + } + } + + offset += lc->cmdsize; + } + } + + return symbol; +}