resolve.h revision 1.83
1/* $OpenBSD: resolve.h,v 1.83 2017/05/08 02:34:01 guenther Exp $ */ 2 3/* 4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29#ifndef _RESOLVE_H_ 30#define _RESOLVE_H_ 31 32#include <sys/queue.h> 33#include <link.h> 34#include <dlfcn.h> 35 36/* Number of low tags that are used saved internally (0 .. DT_NUM-1) */ 37#define DT_NUM (DT_PREINIT_ARRAYSZ + 1) 38 39struct load_list { 40 struct load_list *next; 41 void *start; 42 size_t size; 43 int prot; 44 Elf_Addr moff; 45 long foff; 46}; 47 48/* 49 * Structure describing a loaded object. 50 * The head of this struct must be compatible 51 * with struct link_map in sys/link.h 52 */ 53typedef struct elf_object elf_object_t; 54struct elf_object { 55 Elf_Addr obj_base; /* object's address '0' base */ 56 char *load_name; /* Pointer to object name */ 57 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 58 struct elf_object *next; 59 struct elf_object *prev; 60/* End struct link_map compatible */ 61 Elf_Addr load_base; /* Base address of loadable segments */ 62 63 struct load_list *load_list; 64 65 u_int32_t load_size; 66 67 union { 68 u_long info[DT_NUM + DT_PROCNUM]; 69 struct { 70 Elf_Addr null; /* Not used */ 71 Elf_Addr needed; /* Not used */ 72 Elf_Addr pltrelsz; 73 Elf_Addr *pltgot; 74 Elf_Addr *hash; 75 const char *strtab; 76 const Elf_Sym *symtab; 77 Elf_RelA *rela; 78 Elf_Addr relasz; 79 Elf_Addr relaent; 80 Elf_Addr strsz; 81 Elf_Addr syment; 82 void (*init)(void); 83 void (*fini)(void); 84 const char *soname; 85 const char *rpath; 86 Elf_Addr symbolic; 87 Elf_Rel *rel; 88 Elf_Addr relsz; 89 Elf_Addr relent; 90 Elf_Addr pltrel; 91 Elf_Addr debug; 92 Elf_Addr textrel; 93 Elf_Addr jmprel; 94 Elf_Addr bind_now; 95 void (**init_array)(void); 96 void (**fini_array)(void); 97 Elf_Addr init_arraysz; 98 Elf_Addr fini_arraysz; 99 const char *runpath; 100 Elf_Addr flags; 101 Elf_Addr encoding; 102 void (**preinit_array)(void); 103 Elf_Addr preinit_arraysz; 104 } u; 105 } Dyn; 106#define dyn Dyn.u 107 108 Elf_Addr relacount; /* DT_RELACOUNT */ 109 Elf_Addr relcount; /* DT_RELCOUNT */ 110 111 int status; 112#define STAT_RELOC_DONE 0x01 113#define STAT_GOT_DONE 0x02 114#define STAT_INIT_DONE 0x04 115#define STAT_FINI_DONE 0x08 116#define STAT_FINI_READY 0x10 117#define STAT_UNLOADED 0x20 118#define STAT_NODELETE 0x40 119#define STAT_VISITED 0x80 120 121 Elf_Phdr *phdrp; 122 int phdrc; 123 124 int obj_type; 125#define OBJTYPE_LDR 1 126#define OBJTYPE_EXE 2 127#define OBJTYPE_LIB 3 128#define OBJTYPE_DLO 4 129 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 130 131 Elf_Word *buckets; 132 u_int32_t nbuckets; 133 Elf_Word *chains; 134 u_int32_t nchains; 135 Elf_Dyn *dynamic; 136 137 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 138 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 139 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 140 141 int refcount; /* dep libs only */ 142 int opencount; /* # dlopen() & exe */ 143 int grprefcount; /* load group refs */ 144#define OBJECT_REF_CNT(object) \ 145 ((object->refcount + object->opencount + object->grprefcount)) 146#define OBJECT_DLREF_CNT(object) \ 147 ((object->opencount + object->grprefcount)) 148 149 /* object that caused this module to be loaded, used in symbol lookup */ 150 elf_object_t *load_object; 151 struct sod sod; 152 153 /* for object confirmation */ 154 dev_t dev; 155 ino_t inode; 156 157 /* thread local storage info */ 158 Elf_Addr tls_fsize; 159 Elf_Addr tls_msize; 160 Elf_Addr tls_align; 161 const void *tls_static_data; 162 int tls_offset; 163 164 /* relro bits */ 165 Elf_Addr relro_addr; 166 Elf_Addr relro_size; 167 168 /* generation number of last grpsym insert on this object */ 169 unsigned int grpsym_gen; 170 171 char **rpath; 172 char **runpath; 173 174 /* nonzero if trace enabled for this object */ 175 int traced; 176}; 177 178struct dep_node { 179 TAILQ_ENTRY(dep_node) next_sib; 180 elf_object_t *data; 181}; 182 183 184/* Please don't rename or make hidden; gdb(1) knows about these. */ 185Elf_Addr _dl_bind(elf_object_t *object, int index); 186void _dl_debug_state(void); 187 188/* exported to the application */ 189extern char *__progname; 190 191__BEGIN_HIDDEN_DECLS 192void _dl_add_object(elf_object_t *object); 193elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 194 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 195 const long obase); 196void _dl_remove_object(elf_object_t *object); 197void _dl_cleanup_objects(void); 198void *_dl_protect_segment(elf_object_t *_object, Elf_Addr _addr, 199 const char *_start_sym, const char *_end_sym, int _prot); 200 201elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 202elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 203 204int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 205int _dl_md_reloc_got(elf_object_t *object, int lazy); 206 207Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 208 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 209 const elf_object_t **pobj); 210Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 211 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 212 const elf_object_t **pobj); 213/* 214 * defines for _dl_find_symbol() flag field, three bits of meaning 215 * myself - clear: search all objects, set: search only this object 216 * warnnotfound - clear: no warning, set: warn if not found 217 * inplt - clear: possible plt ref set: real matching function. 218 * 219 * inplt - due to how ELF handles function addresses in shared libraries 220 * &func may actually refer to the plt entry in the main program 221 * rather than the actual function address in the .so file. 222 * This rather bizarre behavior is documented in the SVR4 ABI. 223 * when getting the function address to relocate a PLT entry 224 * the 'real' function address is necessary, not the possible PLT address. 225 */ 226/* myself */ 227#define SYM_SEARCH_ALL 0x00 228#define SYM_SEARCH_SELF 0x01 229#define SYM_SEARCH_OTHER 0x02 230#define SYM_SEARCH_NEXT 0x04 231#define SYM_SEARCH_OBJ 0x08 232/* warnnotfound */ 233#define SYM_NOWARNNOTFOUND 0x00 234#define SYM_WARNNOTFOUND 0x10 235/* inplt */ 236#define SYM_NOTPLT 0x00 237#define SYM_PLT 0x20 238 239#define SYM_DLSYM 0x40 240 241int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 242int _dl_rtld(elf_object_t *object); 243void _dl_call_init(elf_object_t *object); 244void _dl_link_child(elf_object_t *dep, elf_object_t *p); 245void _dl_link_grpsym(elf_object_t *object, int checklist); 246void _dl_cache_grpsym_list(elf_object_t *object); 247void _dl_cache_grpsym_list_setup(elf_object_t *object); 248void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 249void _dl_link_dlopen(elf_object_t *dep); 250void _dl_unlink_dlopen(elf_object_t *dep); 251void _dl_notify_unload_shlib(elf_object_t *object); 252void _dl_unload_shlib(elf_object_t *object); 253void _dl_unload_dlopen(void); 254 255void _dl_run_all_dtors(void); 256 257int _dl_match_file(struct sod *sodp, const char *name, int namelen); 258char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 259void _dl_load_list_free(struct load_list *load_list); 260 261typedef void lock_cb(int); 262void _dl_thread_kern_go(lock_cb *); 263lock_cb *_dl_thread_kern_stop(void); 264 265char *_dl_getenv(const char *, char **); 266void _dl_unsetenv(const char *, char **); 267 268void _dl_trace_setup(char **); 269void _dl_trace_object_setup(elf_object_t *); 270int _dl_trace_plt(const elf_object_t *, const char *); 271 272/* tib.c */ 273void _dl_allocate_tls_offsets(void); 274void _dl_allocate_first_tib(void); 275void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 276 const char *_libname); 277extern int _dl_tib_static_done; 278 279extern elf_object_t *_dl_objects; 280extern elf_object_t *_dl_last_object; 281 282extern elf_object_t *_dl_loading_object; 283 284extern struct r_debug *_dl_debug_map; 285 286extern int _dl_pagesz; 287extern int _dl_errno; 288 289extern char **_dl_libpath; 290 291extern char *_dl_preload; 292extern char *_dl_bindnow; 293extern char *_dl_traceld; 294extern char *_dl_tracefmt1; 295extern char *_dl_tracefmt2; 296extern char *_dl_traceprog; 297extern char *_dl_debug; 298 299extern int _dl_trust; 300 301#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 302 303#define DL_NOT_FOUND 1 304#define DL_CANT_OPEN 2 305#define DL_NOT_ELF 3 306#define DL_CANT_OPEN_REF 4 307#define DL_CANT_MMAP 5 308#define DL_NO_SYMBOL 6 309#define DL_INVALID_HANDLE 7 310#define DL_INVALID_CTL 8 311#define DL_NO_OBJECT 9 312#define DL_CANT_FIND_OBJ 10 313#define DL_CANT_LOAD_OBJ 11 314#define DL_INVALID_MODE 12 315 316#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 317#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 318 319/* symbol lookup cache */ 320typedef struct sym_cache { 321 const elf_object_t *obj; 322 const Elf_Sym *sym; 323 int flags; 324} sym_cache; 325 326extern sym_cache *_dl_symcache; 327extern int _dl_symcachestat_hits; 328extern int _dl_symcachestat_lookups; 329TAILQ_HEAD(dlochld, dep_node); 330extern struct dlochld _dlopened_child_list; 331__END_HIDDEN_DECLS 332 333#endif /* _RESOLVE_H_ */ 334