resolve.h revision 1.80
1/* $OpenBSD: resolve.h,v 1.80 2016/08/23 06:46:17 kettenis 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 36struct load_list { 37 struct load_list *next; 38 void *start; 39 size_t size; 40 int prot; 41 Elf_Addr moff; 42 long foff; 43}; 44 45/* 46 * Structure describing a loaded object. 47 * The head of this struct must be compatible 48 * with struct link_map in sys/link.h 49 */ 50typedef struct elf_object elf_object_t; 51struct elf_object { 52 Elf_Addr obj_base; /* object's address '0' base */ 53 char *load_name; /* Pointer to object name */ 54 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 55 struct elf_object *next; 56 struct elf_object *prev; 57/* End struct link_map compatible */ 58 Elf_Addr load_base; /* Base address of loadable segments */ 59 60 struct load_list *load_list; 61 62 u_int32_t load_size; 63 64 union { 65 u_long info[DT_NUM + DT_PROCNUM]; 66 struct { 67 Elf_Addr null; /* Not used */ 68 Elf_Addr needed; /* Not used */ 69 Elf_Addr pltrelsz; 70 Elf_Addr *pltgot; 71 Elf_Addr *hash; 72 const char *strtab; 73 const Elf_Sym *symtab; 74 Elf_RelA *rela; 75 Elf_Addr relasz; 76 Elf_Addr relaent; 77 Elf_Addr strsz; 78 Elf_Addr syment; 79 void (*init)(void); 80 void (*fini)(void); 81 const char *soname; 82 const char *rpath; 83 Elf_Addr symbolic; 84 Elf_Rel *rel; 85 Elf_Addr relsz; 86 Elf_Addr relent; 87 Elf_Addr pltrel; 88 Elf_Addr debug; 89 Elf_Addr textrel; 90 Elf_Addr jmprel; 91 Elf_Addr bind_now; 92 void (**init_array)(void); 93 void (**fini_array)(void); 94 Elf_Addr init_arraysz; 95 Elf_Addr fini_arraysz; 96 const char *runpath; 97 Elf_Addr flags; 98 Elf_Addr encoding; 99 void (**preinit_array)(void); 100 Elf_Addr preinit_arraysz; 101 } u; 102 } Dyn; 103#define dyn Dyn.u 104 105 Elf_Addr relacount; /* DT_RELACOUNT */ 106 Elf_Addr relcount; /* DT_RELCOUNT */ 107 108 int status; 109#define STAT_RELOC_DONE 0x01 110#define STAT_GOT_DONE 0x02 111#define STAT_INIT_DONE 0x04 112#define STAT_FINI_DONE 0x08 113#define STAT_FINI_READY 0x10 114#define STAT_UNLOADED 0x20 115#define STAT_NODELETE 0x40 116#define STAT_VISITED 0x80 117 118 Elf_Phdr *phdrp; 119 int phdrc; 120 121 int obj_type; 122#define OBJTYPE_LDR 1 123#define OBJTYPE_EXE 2 124#define OBJTYPE_LIB 3 125#define OBJTYPE_DLO 4 126 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 127 128 Elf_Word *buckets; 129 u_int32_t nbuckets; 130 Elf_Word *chains; 131 u_int32_t nchains; 132 Elf_Dyn *dynamic; 133 134 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 135 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 136 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 137 138 int refcount; /* dep libs only */ 139 int opencount; /* # dlopen() & exe */ 140 int grprefcount; /* load group refs */ 141#define OBJECT_REF_CNT(object) \ 142 ((object->refcount + object->opencount + object->grprefcount)) 143#define OBJECT_DLREF_CNT(object) \ 144 ((object->opencount + object->grprefcount)) 145 146 /* object that caused this module to be loaded, used in symbol lookup */ 147 elf_object_t *load_object; 148 struct sod sod; 149 150 /* for object confirmation */ 151 dev_t dev; 152 ino_t inode; 153 154 /* thread local storage info */ 155 Elf_Addr tls_fsize; 156 Elf_Addr tls_msize; 157 Elf_Addr tls_align; 158 const void *tls_static_data; 159 int tls_offset; 160 161 /* relro bits */ 162 Elf_Addr relro_addr; 163 Elf_Addr relro_size; 164 165 /* generation number of last grpsym insert on this object */ 166 unsigned int grpsym_gen; 167 168 char **rpath; 169 170 /* nonzero if trace enabled for this object */ 171 int traced; 172}; 173 174struct dep_node { 175 TAILQ_ENTRY(dep_node) next_sib; 176 elf_object_t *data; 177}; 178 179 180/* Please don't rename or make hidden; gdb(1) knows about these. */ 181Elf_Addr _dl_bind(elf_object_t *object, int index); 182void _dl_debug_state(void); 183 184/* exported to the application */ 185extern char *__progname; 186 187__BEGIN_HIDDEN_DECLS 188void _dl_add_object(elf_object_t *object); 189elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 190 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 191 const long obase); 192void _dl_remove_object(elf_object_t *object); 193void _dl_cleanup_objects(void); 194void *_dl_protect_segment(elf_object_t *_object, Elf_Addr _addr, 195 const char *_start_sym, const char *_end_sym, int _prot); 196 197elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 198elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 199 200int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 201int _dl_md_reloc_got(elf_object_t *object, int lazy); 202 203Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 204 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 205 const elf_object_t **pobj); 206Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 207 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 208 const elf_object_t **pobj); 209/* 210 * defines for _dl_find_symbol() flag field, three bits of meaning 211 * myself - clear: search all objects, set: search only this object 212 * warnnotfound - clear: no warning, set: warn if not found 213 * inplt - clear: possible plt ref set: real matching function. 214 * 215 * inplt - due to how ELF handles function addresses in shared libraries 216 * &func may actually refer to the plt entry in the main program 217 * rather than the actual function address in the .so file. 218 * This rather bizarre behavior is documented in the SVR4 ABI. 219 * when getting the function address to relocate a PLT entry 220 * the 'real' function address is necessary, not the possible PLT address. 221 */ 222/* myself */ 223#define SYM_SEARCH_ALL 0x00 224#define SYM_SEARCH_SELF 0x01 225#define SYM_SEARCH_OTHER 0x02 226#define SYM_SEARCH_NEXT 0x04 227#define SYM_SEARCH_OBJ 0x08 228/* warnnotfound */ 229#define SYM_NOWARNNOTFOUND 0x00 230#define SYM_WARNNOTFOUND 0x10 231/* inplt */ 232#define SYM_NOTPLT 0x00 233#define SYM_PLT 0x20 234 235#define SYM_DLSYM 0x40 236 237int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 238int _dl_rtld(elf_object_t *object); 239void _dl_call_init(elf_object_t *object); 240void _dl_link_child(elf_object_t *dep, elf_object_t *p); 241void _dl_link_grpsym(elf_object_t *object, int checklist); 242void _dl_cache_grpsym_list(elf_object_t *object); 243void _dl_cache_grpsym_list_setup(elf_object_t *object); 244void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 245void _dl_link_dlopen(elf_object_t *dep); 246void _dl_unlink_dlopen(elf_object_t *dep); 247void _dl_notify_unload_shlib(elf_object_t *object); 248void _dl_unload_shlib(elf_object_t *object); 249void _dl_unload_dlopen(void); 250 251void _dl_run_all_dtors(void); 252 253int _dl_match_file(struct sod *sodp, const char *name, int namelen); 254char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 255void _dl_load_list_free(struct load_list *load_list); 256 257void _dl_thread_kern_go(void); 258void _dl_thread_kern_stop(void); 259 260char *_dl_getenv(const char *, char **); 261void _dl_unsetenv(const char *, char **); 262 263void _dl_trace_setup(char **); 264void _dl_trace_object_setup(elf_object_t *); 265int _dl_trace_plt(const elf_object_t *, const char *); 266 267/* tib.c */ 268void _dl_allocate_tls_offsets(void); 269void _dl_allocate_first_tib(void); 270void _dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr, 271 const char *_libname); 272extern int _dl_tib_static_done; 273 274extern elf_object_t *_dl_objects; 275extern elf_object_t *_dl_last_object; 276 277extern elf_object_t *_dl_loading_object; 278 279extern struct r_debug *_dl_debug_map; 280 281extern int _dl_pagesz; 282extern int _dl_errno; 283 284extern char **_dl_libpath; 285 286extern char *_dl_preload; 287extern char *_dl_bindnow; 288extern char *_dl_traceld; 289extern char *_dl_tracefmt1; 290extern char *_dl_tracefmt2; 291extern char *_dl_traceprog; 292extern char *_dl_debug; 293 294extern int _dl_trust; 295 296#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 297 298#define DL_NOT_FOUND 1 299#define DL_CANT_OPEN 2 300#define DL_NOT_ELF 3 301#define DL_CANT_OPEN_REF 4 302#define DL_CANT_MMAP 5 303#define DL_NO_SYMBOL 6 304#define DL_INVALID_HANDLE 7 305#define DL_INVALID_CTL 8 306#define DL_NO_OBJECT 9 307#define DL_CANT_FIND_OBJ 10 308#define DL_CANT_LOAD_OBJ 11 309#define DL_INVALID_MODE 12 310 311#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 312#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 313 314/* symbol lookup cache */ 315typedef struct sym_cache { 316 const elf_object_t *obj; 317 const Elf_Sym *sym; 318 int flags; 319} sym_cache; 320 321extern sym_cache *_dl_symcache; 322extern int _dl_symcachestat_hits; 323extern int _dl_symcachestat_lookups; 324TAILQ_HEAD(dlochld, dep_node); 325extern struct dlochld _dlopened_child_list; 326__END_HIDDEN_DECLS 327 328#endif /* _RESOLVE_H_ */ 329