1 /* $OpenBSD: resolve.h,v 1.55 2007/11/27 16:42:15 miod 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 struct 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 */ 50 typedef struct elf_object elf_object_t; 51 struct elf_object { 52 Elf_Addr load_addr; /* Real load address */ 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_offs; /* Load offset from link address */ 59 60 struct load_list *load_list; 61 62 u_int32_t load_size; 63 Elf_Addr got_addr; 64 Elf_Addr got_start; 65 size_t got_size; 66 Elf_Addr plt_start; 67 size_t plt_size; 68 69 union { 70 u_long info[DT_NUM + DT_PROCNUM]; 71 struct { 72 Elf_Addr null; /* Not used */ 73 Elf_Addr needed; /* Not used */ 74 Elf_Addr pltrelsz; 75 Elf_Addr *pltgot; 76 Elf_Addr *hash; 77 const char *strtab; 78 const Elf_Sym *symtab; 79 Elf_RelA *rela; 80 Elf_Addr relasz; 81 Elf_Addr relaent; 82 Elf_Addr strsz; 83 Elf_Addr syment; 84 void (*init)(void); 85 void (*fini)(void); 86 const char *soname; 87 const char *rpath; 88 Elf_Addr symbolic; 89 Elf_Rel *rel; 90 Elf_Addr relsz; 91 Elf_Addr relent; 92 Elf_Addr pltrel; 93 Elf_Addr debug; 94 Elf_Addr textrel; 95 Elf_Addr jmprel; 96 } u; 97 } Dyn; 98 #define dyn Dyn.u 99 100 int status; 101 #define STAT_RELOC_DONE 0x01 102 #define STAT_GOT_DONE 0x02 103 #define STAT_INIT_DONE 0x04 104 #define STAT_FINI_DONE 0x08 105 #define STAT_FINI_READY 0x10 106 #define STAT_UNLOADED 0x20 107 108 Elf_Phdr *phdrp; 109 int phdrc; 110 111 int obj_type; 112 #define OBJTYPE_LDR 1 113 #define OBJTYPE_EXE 2 114 #define OBJTYPE_LIB 3 115 #define OBJTYPE_DLO 4 116 int obj_flags; 117 118 Elf_Word *buckets; 119 u_int32_t nbuckets; 120 Elf_Word *chains; 121 u_int32_t nchains; 122 Elf_Dyn *dynamic; 123 124 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 125 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 126 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 127 128 int refcount; /* dep libs only */ 129 int opencount; /* # dlopen() & exe */ 130 int grprefcount; /* load group refs */ 131 #define OBJECT_REF_CNT(object) \ 132 ((object->refcount + object->opencount + object->grprefcount)) 133 #define OBJECT_DLREF_CNT(object) \ 134 ((object->opencount + object->grprefcount)) 135 136 /* object that caused this module to be loaded, used in symbol lookup */ 137 elf_object_t *load_object; 138 139 void *prebind_data; 140 141 /* for object confirmation */ 142 dev_t dev; 143 ino_t inode; 144 }; 145 146 struct dep_node { 147 TAILQ_ENTRY(dep_node) next_sib; 148 elf_object_t *data; 149 }; 150 151 void _dl_rt_resolve(void); 152 153 void _dl_add_object(elf_object_t *object); 154 elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 155 const long *, const int objtype, const long laddr, const long loff); 156 void _dl_remove_object(elf_object_t *object); 157 void _dl_cleanup_objects(void); 158 159 elf_object_t *_dl_lookup_object(const char *objname); 160 elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 161 elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 162 163 int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 164 int _dl_md_reloc_got(elf_object_t *object, int lazy); 165 166 Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 167 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 168 const elf_object_t **pobj); 169 Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 170 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 171 const elf_object_t **pobj); 172 /* 173 * defines for _dl_find_symbol() flag field, three bits of meaning 174 * myself - clear: search all objects, set: search only this object 175 * warnnotfound - clear: no warning, set: warn if not found 176 * inplt - clear: possible plt ref set: real matching function. 177 * 178 * inplt - due to how ELF handles function addresses in shared libraries 179 * &func may actually refer to the plt entry in the main program 180 * rather than the actual function address in the .so file. 181 * This rather bizarre behavior is documented in the SVR4 ABI. 182 * when getting the function address to relocate a PLT entry 183 * the 'real' function address is necessary, not the possible PLT address. 184 */ 185 /* myself */ 186 #define SYM_SEARCH_ALL 0x00 187 #define SYM_SEARCH_SELF 0x01 188 #define SYM_SEARCH_OTHER 0x02 189 #define SYM_SEARCH_NEXT 0x04 190 #define SYM_SEARCH_OBJ 0x08 191 /* warnnotfound */ 192 #define SYM_NOWARNNOTFOUND 0x00 193 #define SYM_WARNNOTFOUND 0x10 194 /* inplt */ 195 #define SYM_NOTPLT 0x00 196 #define SYM_PLT 0x20 197 198 #define SYM_DLSYM 0x40 199 200 int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 201 int _dl_rtld(elf_object_t *object); 202 void _dl_call_init(elf_object_t *object); 203 void _dl_link_child(elf_object_t *dep, elf_object_t *p); 204 void _dl_link_grpsym(elf_object_t *object); 205 void _dl_cache_grpsym_list(elf_object_t *object); 206 void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 207 void _dl_link_dlopen(elf_object_t *dep); 208 void _dl_unlink_dlopen(elf_object_t *dep); 209 void _dl_notify_unload_shlib(elf_object_t *object); 210 void _dl_unload_shlib(elf_object_t *object); 211 void _dl_unload_dlopen(void); 212 213 void _dl_run_all_dtors(void); 214 215 /* Please don't rename; gdb(1) knows about this. */ 216 Elf_Addr _dl_bind(elf_object_t *object, int index); 217 218 int _dl_match_file(struct sod *sodp, char *name, int namelen); 219 char *_dl_find_shlib(struct sod *sodp, const char *searchpath, int nohints); 220 void _dl_load_list_free(struct load_list *load_list); 221 222 void _dl_thread_kern_go(void); 223 void _dl_thread_kern_stop(void); 224 225 void _dl_thread_bind_lock(int); 226 227 extern elf_object_t *_dl_objects; 228 extern elf_object_t *_dl_last_object; 229 230 extern elf_object_t *_dl_loading_object; 231 232 extern const char *_dl_progname; 233 extern struct r_debug *_dl_debug_map; 234 235 extern int _dl_pagesz; 236 extern int _dl_errno; 237 238 extern char *_dl_libpath; 239 extern char *_dl_preload; 240 extern char *_dl_bindnow; 241 extern char *_dl_traceld; 242 extern char *_dl_tracefmt1; 243 extern char *_dl_tracefmt2; 244 extern char *_dl_traceprog; 245 extern char *_dl_debug; 246 247 #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 248 249 #define DL_NOT_FOUND 1 250 #define DL_CANT_OPEN 2 251 #define DL_NOT_ELF 3 252 #define DL_CANT_OPEN_REF 4 253 #define DL_CANT_MMAP 5 254 #define DL_NO_SYMBOL 6 255 #define DL_INVALID_HANDLE 7 256 #define DL_INVALID_CTL 8 257 #define DL_NO_OBJECT 9 258 #define DL_CANT_FIND_OBJ 10 259 #define DL_CANT_LOAD_OBJ 11 260 261 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 262 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 263 264 /* symbol lookup cache */ 265 typedef struct sym_cache { 266 const elf_object_t *obj; 267 const Elf_Sym *sym; 268 int flags; 269 } sym_cache; 270 271 extern sym_cache *_dl_symcache; 272 extern int _dl_symcachestat_hits; 273 extern int _dl_symcachestat_lookups; 274 TAILQ_HEAD(dlochld, dep_node); 275 extern struct dlochld _dlopened_child_list; 276 277 278 #endif /* _RESOLVE_H_ */ 279