resolve.h revision 1.73
1/* $OpenBSD: resolve.h,v 1.73 2015/09/19 20:56:47 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 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 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 Elf_Addr relacount; /* DT_RELACOUNT */ 101 Elf_Addr relcount; /* DT_RELCOUNT */ 102 103 int status; 104#define STAT_RELOC_DONE 0x01 105#define STAT_GOT_DONE 0x02 106#define STAT_INIT_DONE 0x04 107#define STAT_FINI_DONE 0x08 108#define STAT_FINI_READY 0x10 109#define STAT_UNLOADED 0x20 110#define STAT_NODELETE 0x40 111#define STAT_VISITED 0x80 112 113 Elf_Phdr *phdrp; 114 int phdrc; 115 116 int obj_type; 117#define OBJTYPE_LDR 1 118#define OBJTYPE_EXE 2 119#define OBJTYPE_LIB 3 120#define OBJTYPE_DLO 4 121 int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */ 122 123 Elf_Word *buckets; 124 u_int32_t nbuckets; 125 Elf_Word *chains; 126 u_int32_t nchains; 127 Elf_Dyn *dynamic; 128 129 TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */ 130 TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */ 131 TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */ 132 133 int refcount; /* dep libs only */ 134 int opencount; /* # dlopen() & exe */ 135 int grprefcount; /* load group refs */ 136#define OBJECT_REF_CNT(object) \ 137 ((object->refcount + object->opencount + object->grprefcount)) 138#define OBJECT_DLREF_CNT(object) \ 139 ((object->opencount + object->grprefcount)) 140 141 /* object that caused this module to be loaded, used in symbol lookup */ 142 elf_object_t *load_object; 143 struct sod sod; 144 145 void *prebind_data; 146 147 /* for object confirmation */ 148 dev_t dev; 149 ino_t inode; 150 151 /* last symbol lookup on this object, to avoid mutiple searches */ 152 int lastlookup_head; 153 int lastlookup; 154 155 char **rpath; 156 157 /* nonzero if trace enabled for this object */ 158 int traced; 159}; 160 161struct dep_node { 162 TAILQ_ENTRY(dep_node) next_sib; 163 elf_object_t *data; 164}; 165 166void _dl_add_object(elf_object_t *object); 167elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 168 Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase, 169 const long obase); 170void _dl_remove_object(elf_object_t *object); 171void _dl_cleanup_objects(void); 172 173elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 174elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags); 175 176int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 177int _dl_md_reloc_got(elf_object_t *object, int lazy); 178 179Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this, 180 int flags, const Elf_Sym *ref_sym, elf_object_t *object, 181 const elf_object_t **pobj); 182Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 183 const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym, 184 const elf_object_t **pobj); 185/* 186 * defines for _dl_find_symbol() flag field, three bits of meaning 187 * myself - clear: search all objects, set: search only this object 188 * warnnotfound - clear: no warning, set: warn if not found 189 * inplt - clear: possible plt ref set: real matching function. 190 * 191 * inplt - due to how ELF handles function addresses in shared libraries 192 * &func may actually refer to the plt entry in the main program 193 * rather than the actual function address in the .so file. 194 * This rather bizarre behavior is documented in the SVR4 ABI. 195 * when getting the function address to relocate a PLT entry 196 * the 'real' function address is necessary, not the possible PLT address. 197 */ 198/* myself */ 199#define SYM_SEARCH_ALL 0x00 200#define SYM_SEARCH_SELF 0x01 201#define SYM_SEARCH_OTHER 0x02 202#define SYM_SEARCH_NEXT 0x04 203#define SYM_SEARCH_OBJ 0x08 204/* warnnotfound */ 205#define SYM_NOWARNNOTFOUND 0x00 206#define SYM_WARNNOTFOUND 0x10 207/* inplt */ 208#define SYM_NOTPLT 0x00 209#define SYM_PLT 0x20 210 211#define SYM_DLSYM 0x40 212 213int _dl_load_dep_libs(elf_object_t *object, int flags, int booting); 214int _dl_rtld(elf_object_t *object); 215void _dl_call_init(elf_object_t *object); 216void _dl_link_child(elf_object_t *dep, elf_object_t *p); 217void _dl_link_grpsym(elf_object_t *object, int checklist); 218void _dl_cache_grpsym_list(elf_object_t *object); 219void _dl_cache_grpsym_list_setup(elf_object_t *object); 220void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object); 221void _dl_link_dlopen(elf_object_t *dep); 222void _dl_unlink_dlopen(elf_object_t *dep); 223void _dl_notify_unload_shlib(elf_object_t *object); 224void _dl_unload_shlib(elf_object_t *object); 225void _dl_unload_dlopen(void); 226 227void _dl_run_all_dtors(void); 228 229/* Please don't rename; gdb(1) knows about this. */ 230Elf_Addr _dl_bind(elf_object_t *object, int index); 231 232int _dl_match_file(struct sod *sodp, const char *name, int namelen); 233char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints); 234void _dl_load_list_free(struct load_list *load_list); 235void _dl_debug_state(void); 236 237void _dl_thread_kern_go(void); 238void _dl_thread_kern_stop(void); 239 240char *_dl_getenv(const char *, char **); 241void _dl_unsetenv(const char *, char **); 242 243void _dl_trace_setup(char **); 244void _dl_trace_object_setup(elf_object_t *); 245int _dl_trace_plt(const elf_object_t *, const char *); 246 247extern elf_object_t *_dl_objects; 248extern elf_object_t *_dl_last_object; 249 250extern elf_object_t *_dl_loading_object; 251 252extern const char *_dl_progname; 253extern struct r_debug *_dl_debug_map; 254 255extern int _dl_pagesz; 256extern int _dl_errno; 257 258extern char **_dl_libpath; 259 260extern char *_dl_preload; 261extern char *_dl_bindnow; 262extern char *_dl_traceld; 263extern char *_dl_tracefmt1; 264extern char *_dl_tracefmt2; 265extern char *_dl_traceprog; 266extern char *_dl_debug; 267 268extern int _dl_trust; 269 270#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 271 272#define DL_NOT_FOUND 1 273#define DL_CANT_OPEN 2 274#define DL_NOT_ELF 3 275#define DL_CANT_OPEN_REF 4 276#define DL_CANT_MMAP 5 277#define DL_NO_SYMBOL 6 278#define DL_INVALID_HANDLE 7 279#define DL_INVALID_CTL 8 280#define DL_NO_OBJECT 9 281#define DL_CANT_FIND_OBJ 10 282#define DL_CANT_LOAD_OBJ 11 283#define DL_INVALID_MODE 12 284 285#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 286#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 287 288/* symbol lookup cache */ 289typedef struct sym_cache { 290 const elf_object_t *obj; 291 const Elf_Sym *sym; 292 int flags; 293} sym_cache; 294 295extern sym_cache *_dl_symcache; 296extern int _dl_symcachestat_hits; 297extern int _dl_symcachestat_lookups; 298TAILQ_HEAD(dlochld, dep_node); 299extern struct dlochld _dlopened_child_list; 300 301/* variables used to avoid duplicate node checking */ 302extern int _dl_searchnum; 303extern uint32_t _dl_skipnum; 304void _dl_newsymsearch(void); 305 306#endif /* _RESOLVE_H_ */ 307