/* $OpenBSD: resolve.h,v 1.71 2015/01/22 05:48:17 deraadt Exp $ */ /* * Copyright (c) 1998 Per Fogelstrom, Opsycon AB * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ #ifndef _RESOLVE_H_ #define _RESOLVE_H_ #include #include #include #include struct load_list { struct load_list *next; void *start; size_t size; int prot; Elf_Addr moff; long foff; }; /* * Structure describing a loaded object. * The head of this struct must be compatible * with struct link_map in sys/link.h */ typedef struct elf_object elf_object_t; struct elf_object { Elf_Addr obj_base; /* object's address '0' base */ char *load_name; /* Pointer to object name */ Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ struct elf_object *next; struct elf_object *prev; /* End struct link_map compatible */ Elf_Addr load_base; /* Base address of loadable segments */ struct load_list *load_list; u_int32_t load_size; Elf_Addr got_addr; Elf_Addr got_start; size_t got_size; Elf_Addr plt_start; size_t plt_size; union { u_long info[DT_NUM + DT_PROCNUM]; struct { Elf_Addr null; /* Not used */ Elf_Addr needed; /* Not used */ Elf_Addr pltrelsz; Elf_Addr *pltgot; Elf_Addr *hash; const char *strtab; const Elf_Sym *symtab; Elf_RelA *rela; Elf_Addr relasz; Elf_Addr relaent; Elf_Addr strsz; Elf_Addr syment; void (*init)(void); void (*fini)(void); const char *soname; const char *rpath; Elf_Addr symbolic; Elf_Rel *rel; Elf_Addr relsz; Elf_Addr relent; Elf_Addr pltrel; Elf_Addr debug; Elf_Addr textrel; Elf_Addr jmprel; } u; } Dyn; #define dyn Dyn.u Elf_Addr relacount; /* DT_RELACOUNT */ Elf_Addr relcount; /* DT_RELCOUNT */ int status; #define STAT_RELOC_DONE 0x01 #define STAT_GOT_DONE 0x02 #define STAT_INIT_DONE 0x04 #define STAT_FINI_DONE 0x08 #define STAT_FINI_READY 0x10 #define STAT_UNLOADED 0x20 #define STAT_NODELETE 0x40 #define STAT_VISITED 0x80 Elf_Phdr *phdrp; int phdrc; int obj_type; #define OBJTYPE_LDR 1 #define OBJTYPE_EXE 2 #define OBJTYPE_LIB 3 #define OBJTYPE_DLO 4 int obj_flags; /* c.f. DF_1_* */ Elf_Word *buckets; u_int32_t nbuckets; Elf_Word *chains; u_int32_t nchains; Elf_Dyn *dynamic; TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ int refcount; /* dep libs only */ int opencount; /* # dlopen() & exe */ int grprefcount; /* load group refs */ #define OBJECT_REF_CNT(object) \ ((object->refcount + object->opencount + object->grprefcount)) #define OBJECT_DLREF_CNT(object) \ ((object->opencount + object->grprefcount)) /* object that caused this module to be loaded, used in symbol lookup */ elf_object_t *load_object; struct sod sod; void *prebind_data; /* for object confirmation */ dev_t dev; ino_t inode; /* last symbol lookup on this object, to avoid mutiple searches */ int lastlookup_head; int lastlookup; char **rpath; /* nonzero if trace enabled for this object */ int traced; }; struct dep_node { TAILQ_ENTRY(dep_node) next_sib; elf_object_t *data; }; void _dl_add_object(elf_object_t *object); elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, const long obase); void _dl_remove_object(elf_object_t *object); void _dl_cleanup_objects(void); elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); int _dl_md_reloc(elf_object_t *object, int rel, int relsz); int _dl_md_reloc_got(elf_object_t *object, int lazy); Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, int flags, const Elf_Sym *ref_sym, elf_object_t *object, const elf_object_t **pobj); Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, const elf_object_t **pobj); /* * defines for _dl_find_symbol() flag field, three bits of meaning * myself - clear: search all objects, set: search only this object * warnnotfound - clear: no warning, set: warn if not found * inplt - clear: possible plt ref set: real matching function. * * inplt - due to how ELF handles function addresses in shared libraries * &func may actually refer to the plt entry in the main program * rather than the actual function address in the .so file. * This rather bizarre behavior is documented in the SVR4 ABI. * when getting the function address to relocate a PLT entry * the 'real' function address is necessary, not the possible PLT address. */ /* myself */ #define SYM_SEARCH_ALL 0x00 #define SYM_SEARCH_SELF 0x01 #define SYM_SEARCH_OTHER 0x02 #define SYM_SEARCH_NEXT 0x04 #define SYM_SEARCH_OBJ 0x08 /* warnnotfound */ #define SYM_NOWARNNOTFOUND 0x00 #define SYM_WARNNOTFOUND 0x10 /* inplt */ #define SYM_NOTPLT 0x00 #define SYM_PLT 0x20 #define SYM_DLSYM 0x40 int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); int _dl_rtld(elf_object_t *object); void _dl_call_init(elf_object_t *object); void _dl_link_child(elf_object_t *dep, elf_object_t *p); void _dl_link_grpsym(elf_object_t *object, int checklist); void _dl_cache_grpsym_list(elf_object_t *object); void _dl_cache_grpsym_list_setup(elf_object_t *object); void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); void _dl_link_dlopen(elf_object_t *dep); void _dl_unlink_dlopen(elf_object_t *dep); void _dl_notify_unload_shlib(elf_object_t *object); void _dl_unload_shlib(elf_object_t *object); void _dl_unload_dlopen(void); void _dl_run_all_dtors(void); /* Please don't rename; gdb(1) knows about this. */ Elf_Addr _dl_bind(elf_object_t *object, int index); int _dl_match_file(struct sod *sodp, const char *name, int namelen); char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); void _dl_load_list_free(struct load_list *load_list); void _dl_debug_state(void); void _dl_thread_kern_go(void); void _dl_thread_kern_stop(void); void _dl_thread_bind_lock(int, sigset_t *); char *_dl_getenv(const char *, char **); void _dl_unsetenv(const char *, char **); void _dl_trace_setup(char **); void _dl_trace_object_setup(elf_object_t *); int _dl_trace_plt(const elf_object_t *, const char *); extern elf_object_t *_dl_objects; extern elf_object_t *_dl_last_object; extern elf_object_t *_dl_loading_object; extern const char *_dl_progname; extern struct r_debug *_dl_debug_map; extern int _dl_pagesz; extern int _dl_errno; extern char **_dl_libpath; extern char *_dl_preload; extern char *_dl_bindnow; extern char *_dl_traceld; extern char *_dl_tracefmt1; extern char *_dl_tracefmt2; extern char *_dl_traceprog; extern char *_dl_debug; extern int _dl_trust; #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) #define DL_NOT_FOUND 1 #define DL_CANT_OPEN 2 #define DL_NOT_ELF 3 #define DL_CANT_OPEN_REF 4 #define DL_CANT_MMAP 5 #define DL_NO_SYMBOL 6 #define DL_INVALID_HANDLE 7 #define DL_INVALID_CTL 8 #define DL_NO_OBJECT 9 #define DL_CANT_FIND_OBJ 10 #define DL_CANT_LOAD_OBJ 11 #define DL_INVALID_MODE 12 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) /* symbol lookup cache */ typedef struct sym_cache { const elf_object_t *obj; const Elf_Sym *sym; int flags; } sym_cache; extern sym_cache *_dl_symcache; extern int _dl_symcachestat_hits; extern int _dl_symcachestat_lookups; TAILQ_HEAD(dlochld, dep_node); extern struct dlochld _dlopened_child_list; /* variables used to avoid duplicate node checking */ int _dl_searchnum; uint32_t _dl_skipnum; void _dl_newsymsearch(void); #endif /* _RESOLVE_H_ */