1 /* $OpenBSD: resolve.h,v 1.35 2005/04/06 00:16:53 deraadt 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 <link.h> 33 #include <dlfcn.h> 34 35 struct load_list { 36 struct load_list *next; 37 void *start; 38 size_t size; 39 int prot; 40 Elf_Addr moff; 41 long foff; 42 }; 43 44 /* 45 * Structure describing a loaded object. 46 * The head of this struct must be compatible 47 * with struct link_map in sys/link.h 48 */ 49 typedef struct elf_object { 50 Elf_Addr load_addr; /* Real load address */ 51 char *load_name; /* Pointer to object name */ 52 Elf_Dyn *load_dyn; /* Pointer to object dynamic data */ 53 struct elf_object *next; 54 struct elf_object *prev; 55 /* End struct link_map compatible */ 56 Elf_Addr load_offs; /* Load offset from link address */ 57 58 struct load_list *load_list; 59 60 u_int32_t load_size; 61 Elf_Addr got_addr; 62 Elf_Addr got_start; 63 size_t got_size; 64 Elf_Addr plt_start; 65 size_t plt_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 } u; 96 } Dyn; 97 #define dyn Dyn.u 98 99 struct elf_object *dep_next; /* Shadow objects for resolve search */ 100 101 int status; 102 #define STAT_RELOC_DONE 1 103 #define STAT_GOT_DONE 2 104 #define STAT_INIT_DONE 4 105 106 Elf_Phdr *phdrp; 107 int phdrc; 108 109 int refcount; 110 int obj_type; 111 #define OBJTYPE_LDR 1 112 #define OBJTYPE_EXE 2 113 #define OBJTYPE_LIB 3 114 #define OBJTYPE_DLO 4 115 int obj_flags; 116 117 Elf_Word *buckets; 118 u_int32_t nbuckets; 119 Elf_Word *chains; 120 u_int32_t nchains; 121 Elf_Dyn *dynamic; 122 123 struct dep_node *first_child; 124 struct dep_node *last_child; 125 126 /* for object confirmation */ 127 dev_t dev; 128 ino_t inode; 129 } elf_object_t; 130 131 struct dep_node { 132 struct dep_node *next_sibling; 133 elf_object_t *data; 134 }; 135 136 extern void _dl_rt_resolve(void); 137 138 void _dl_add_object(elf_object_t *object); 139 extern elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp, 140 const u_long *, const int objtype, const long laddr, const long loff); 141 extern void _dl_remove_object(elf_object_t *object); 142 143 extern elf_object_t *_dl_lookup_object(const char *objname); 144 extern elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int); 145 extern void _dl_unload_shlib(elf_object_t *object); 146 elf_object_t *_dl_tryload_shlib(const char *libname, int type); 147 148 extern int _dl_md_reloc(elf_object_t *object, int rel, int relsz); 149 extern void _dl_md_reloc_got(elf_object_t *object, int lazy); 150 151 Elf_Addr _dl_find_symbol(const char *name, elf_object_t *startlook, 152 const Elf_Sym **ref, const elf_object_t **pobj, 153 int flags, int sym_size, elf_object_t *object); 154 Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 155 elf_object_t *startlook, const Elf_Sym **ref, const elf_object_t **pobj, 156 int flags, int req_size); 157 /* 158 * defines for _dl_find_symbol() flag field, three bits of meaning 159 * myself - clear: search all objects, set: search only this object 160 * warnnotfound - clear: no warning, set: warn if not found 161 * inplt - clear: possible plt ref set: real matching function. 162 * 163 * inplt - due to how ELF handles function addresses in shared libraries 164 * &func may actually refer to the plt entry in the main program 165 * rather than the actual function address in the .so file. 166 * This rather bizarre behavior is documented in the SVR4 ABI. 167 * when getting the function address to relocate a PLT entry 168 * the 'real' function address is necessary, not the possible PLT address. 169 */ 170 /* myself */ 171 #define SYM_SEARCH_ALL 0 172 #define SYM_SEARCH_SELF 1 173 /* warnnotfound */ 174 #define SYM_NOWARNNOTFOUND 0 175 #define SYM_WARNNOTFOUND 2 176 /* inplt */ 177 #define SYM_NOTPLT 0 178 #define SYM_PLT 4 179 180 void _dl_rtld(elf_object_t *object); 181 void _dl_call_init(elf_object_t *object); 182 void _dl_link_sub(elf_object_t *dep, elf_object_t *p); 183 184 void _dl_run_dtors(elf_object_t *object); 185 186 Elf_Addr _dl_bind(elf_object_t *object, int index); 187 188 int _dl_match_file(struct sod *sodp, char *name, int namelen); 189 char *_dl_find_shlib(struct sod *sodp, const char *searchpath, int nohints); 190 void _dl_load_list_free(struct load_list *load_list); 191 192 extern elf_object_t *_dl_objects; 193 extern elf_object_t *_dl_last_object; 194 195 extern const char *_dl_progname; 196 extern struct r_debug *_dl_debug_map; 197 198 extern int _dl_pagesz; 199 extern int _dl_errno; 200 201 extern char *_dl_libpath; 202 extern char *_dl_preload; 203 extern char *_dl_bindnow; 204 extern char *_dl_traceld; 205 extern char *_dl_debug; 206 207 #define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0) 208 209 #define DL_NOT_FOUND 1 210 #define DL_CANT_OPEN 2 211 #define DL_NOT_ELF 3 212 #define DL_CANT_OPEN_REF 4 213 #define DL_CANT_MMAP 5 214 #define DL_NO_SYMBOL 6 215 #define DL_INVALID_HANDLE 7 216 #define DL_INVALID_CTL 8 217 #define DL_NO_OBJECT 9 218 #define DL_CANT_FIND_OBJ 10 219 220 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1)) 221 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1)) 222 223 /* symbol lookup cache */ 224 typedef struct sym_cache { 225 const elf_object_t *obj; 226 const Elf_Sym *sym; 227 int flags; 228 } sym_cache; 229 230 extern sym_cache *_dl_symcache; 231 232 #endif /* _RESOLVE_H_ */ 233