rtld.h revision 1.53
1 /* $NetBSD: rtld.h,v 1.53 2002/09/23 23:56:49 mycroft Exp $ */ 2 3 /* 4 * Copyright 1996 John D. Polstra. 5 * Copyright 1996 Matt Thomas <matt (at) 3am-software.com> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by John Polstra. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #ifndef RTLD_H 35 #define RTLD_H 36 37 #include <dlfcn.h> 38 #include <stddef.h> 39 #include <sys/param.h> 40 #include <sys/types.h> 41 #include <sys/queue.h> 42 #include <sys/exec_elf.h> 43 #include "rtldenv.h" 44 #include "link.h" 45 46 #if defined(_RTLD_SOURCE) 47 48 #ifndef RTLD_DEFAULT_LIBRARY_PATH 49 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib" 50 #endif 51 #define _PATH_LD_HINTS "/etc/ld.so.conf" 52 53 #if 0 54 #define SVR4_LIBDIR "/usr/lib" 55 #endif 56 57 #define LIBDIRLEN (sizeof LIBDIR - 1) 58 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 59 60 #ifndef PAGESIZE 61 # ifdef VARPSZ 62 extern int _rtld_pagesz; 63 # ifdef RTLD_DEBUG 64 # define PAGESIZE (assert(_rtld_pagesz), _rtld_pagesz) 65 # else 66 # define PAGESIZE _rtld_pagesz 67 # endif 68 # else 69 # define PAGESIZE NBPG 70 # endif 71 #endif 72 73 #define round_down(x) ((x) & ~(PAGESIZE-1)) 74 #define round_up(x) round_down((x) + PAGESIZE - 1) 75 76 #define NEW(type) ((type *) xmalloc(sizeof(type))) 77 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 78 79 #endif /* _RTLD_SOURCE */ 80 81 /* 82 * C++ has mandated the use of the following keywords for its new boolean 83 * type. We might as well follow their lead. 84 */ 85 typedef enum { 86 false = 0, 87 true = 1 88 } bool; 89 90 struct Struct_Obj_Entry; 91 92 typedef struct Struct_Objlist_Entry { 93 SIMPLEQ_ENTRY(Struct_Objlist_Entry) link; 94 struct Struct_Obj_Entry *obj; 95 } Objlist_Entry; 96 97 typedef SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 98 99 typedef struct Struct_Needed_Entry { 100 struct Struct_Needed_Entry *next; 101 struct Struct_Obj_Entry *obj; 102 unsigned long name; /* Offset of name in string table */ 103 } Needed_Entry; 104 105 typedef struct _rtld_search_path_t { 106 struct _rtld_search_path_t *sp_next; 107 const char *sp_path; 108 size_t sp_pathlen; 109 } Search_Path; 110 111 112 #define RTLD_MAX_ENTRY 10 113 #define RTLD_MAX_LIBRARY 4 114 #define RTLD_MAX_CTL 2 115 typedef struct _rtld_library_xform_t { 116 struct _rtld_library_xform_t *next; 117 char *name; 118 int ctl[RTLD_MAX_CTL]; 119 int ctltype[RTLD_MAX_CTL]; 120 int ctlmax; 121 struct { 122 char *value; 123 char *library[RTLD_MAX_LIBRARY]; 124 } entry[RTLD_MAX_ENTRY]; 125 } Library_Xform; 126 127 /* 128 * Shared object descriptor. 129 * 130 * Items marked with "(%)" are dynamically allocated, and must be freed 131 * when the structure is destroyed. 132 */ 133 134 #define RTLD_MAGIC 0xd550b87a 135 #define RTLD_VERSION 1 136 137 typedef struct Struct_Obj_Entry { 138 Elf32_Word magic; /* Magic number (sanity check) */ 139 Elf32_Word version; /* Version number of struct format */ 140 141 struct Struct_Obj_Entry *next; 142 char *path; /* Pathname of underlying file (%) */ 143 int refcount; 144 int dl_refcount; /* Number of times loaded by dlopen */ 145 146 /* These items are computed by map_object() or by digest_phdr(). */ 147 caddr_t mapbase; /* Base address of mapped region */ 148 size_t mapsize; /* Size of mapped region in bytes */ 149 size_t textsize; /* Size of text segment in bytes */ 150 Elf_Addr vaddrbase; /* Base address in shared object file */ 151 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 152 Elf_Dyn *dynamic; /* Dynamic section */ 153 caddr_t entry; /* Entry point */ 154 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 155 size_t phsize; /* Size of program header in bytes */ 156 157 /* Items from the dynamic section. */ 158 Elf_Addr *pltgot; /* PLTGOT table */ 159 const Elf_Rel *rel; /* Relocation entries */ 160 const Elf_Rel *rellim; /* Limit of Relocation entries */ 161 const Elf_Rela *rela; /* Relocation entries */ 162 const Elf_Rela *relalim; /* Limit of Relocation entries */ 163 const Elf_Rel *pltrel; /* PLT relocation entries */ 164 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 165 const Elf_Rela *pltrela; /* PLT relocation entries */ 166 const Elf_Rela *pltrelalim; /* Limit of PLT relocation entries */ 167 const Elf_Sym *symtab; /* Symbol table */ 168 const char *strtab; /* String table */ 169 unsigned long strsize; /* Size in bytes of string table */ 170 #if defined(__mips__) 171 Elf_Word local_gotno; /* Number of local GOT entries */ 172 Elf_Word symtabno; /* Number of dynamic symbols */ 173 Elf_Word gotsym; /* First dynamic symbol in GOT */ 174 #endif 175 176 const Elf_Word *buckets; /* Hash table buckets array */ 177 unsigned long nbuckets; /* Number of buckets */ 178 const Elf_Word *chains; /* Hash table chain array */ 179 unsigned long nchains; /* Number of chains */ 180 181 Search_Path *rpaths; /* Search path specified in object */ 182 Needed_Entry *needed; /* Shared objects needed by this (%) */ 183 184 void (*init) /* Initialization function to call */ 185 __P((void)); 186 void (*fini) /* Termination function to call */ 187 __P((void)); 188 189 /* Entry points for dlopen() and friends. */ 190 void *(*dlopen) __P((const char *, int)); 191 void *(*dlsym) __P((void *, const char *)); 192 char *(*dlerror) __P((void)); 193 int (*dlclose) __P((void *)); 194 int (*dladdr) __P((const void *, Dl_info *)); 195 196 u_int32_t mainprog:1, /* True if this is the main program */ 197 rtld:1, /* True if this is the dynamic linker */ 198 textrel:1, /* True if there are relocations to 199 * text seg */ 200 symbolic:1, /* True if generated with 201 * "-Bsymbolic" */ 202 printed:1, /* True if ldd has printed it */ 203 isdynamic:1; /* True if this is a pure PIC object */ 204 205 struct link_map linkmap; /* for GDB */ 206 207 /* These items are computed by map_object() or by digest_phdr(). */ 208 const char *interp; /* Pathname of the interpreter, if any */ 209 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 210 Objlist dagmembers; /* DAG has these members (%) */ 211 dev_t dev; /* Object's filesystem's device */ 212 ino_t ino; /* Object's inode number */ 213 } Obj_Entry; 214 215 #if defined(_RTLD_SOURCE) 216 217 extern struct r_debug _rtld_debug; 218 extern Search_Path *_rtld_default_paths; 219 extern Obj_Entry *_rtld_objlist; 220 extern Obj_Entry **_rtld_objtail; 221 extern Obj_Entry *_rtld_objmain; 222 extern Obj_Entry _rtld_objself; 223 extern Search_Path *_rtld_paths; 224 extern Library_Xform *_rtld_xforms; 225 extern bool _rtld_trust; 226 extern const char *_rtld_error_message; 227 extern Objlist _rtld_list_global; 228 extern Objlist _rtld_list_main; 229 extern Elf_Sym _rtld_sym_zero; 230 231 /* rtld.c */ 232 void _rtld_error __P((const char *, ...)) 233 __attribute__((__format__(__printf__,1,2))); 234 void _rtld_die __P((void)); 235 char *_rtld_dlerror __P((void)); 236 void *_rtld_dlopen __P((const char *, int)); 237 void *_rtld_objmain_sym __P((const char *)); 238 void *_rtld_dlsym __P((void *, const char *)); 239 int _rtld_dlclose __P((void *)); 240 int _rtld_dladdr __P((const void *, Dl_info *)); 241 void _rtld_debug_state __P((void)); 242 void _rtld_linkmap_add __P((Obj_Entry *)); 243 void _rtld_linkmap_delete __P((Obj_Entry *)); 244 void _rtld_objlist_add __P((Objlist *, Obj_Entry *)); 245 Objlist_Entry *_rtld_objlist_find __P((Objlist *, const Obj_Entry *)); 246 247 /* headers.c */ 248 void _rtld_digest_dynamic __P((Obj_Entry *)); 249 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 250 251 /* load.c */ 252 Obj_Entry *_rtld_load_object __P((char *, int)); 253 int _rtld_load_needed_objects __P((Obj_Entry *, int)); 254 int _rtld_preload __P((const char *)); 255 256 /* path.c */ 257 void _rtld_add_paths __P((Search_Path **, const char *)); 258 void _rtld_process_hints __P((Search_Path **, Library_Xform **, const char *)); 259 260 /* reloc.c */ 261 int _rtld_do_copy_relocations __P((const Obj_Entry *)); 262 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 263 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 264 int _rtld_relocate_nonplt_objects __P((const Obj_Entry *, bool)); 265 int _rtld_relocate_plt_lazy __P((const Obj_Entry *)); 266 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_Rela *, 267 caddr_t *)); 268 int _rtld_relocate_plt_objects __P((const Obj_Entry *)); 269 void _rtld_setup_pltgot __P((const Obj_Entry *)); 270 271 /* search.c */ 272 Obj_Entry *_rtld_load_library __P((const char *, const Obj_Entry *, int)); 273 274 /* symbol.c */ 275 unsigned long _rtld_elf_hash __P((const char *)); 276 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 277 const Obj_Entry *)); 278 const Elf_Sym *_rtld_find_symdef __P((unsigned long, const Obj_Entry *, 279 const Obj_Entry **, bool)); 280 const Elf_Sym *_rtld_symlook_list(const char *, unsigned long, 281 Objlist *, const Obj_Entry **); 282 283 /* map_object.c */ 284 Obj_Entry *_rtld_map_object __P((char *, int, const struct stat *)); 285 void _rtld_obj_free(Obj_Entry *); 286 Obj_Entry *_rtld_obj_new(void); 287 288 /* function descriptors */ 289 #ifdef __HAVE_FUNCTION_DESCRIPTORS 290 Elf_Addr _rtld_function_descriptor_alloc __P((const Obj_Entry *, 291 const Elf_Sym *, Elf_Addr)); 292 const void *_rtld_function_descriptor_function __P((const void *)); 293 #endif /* __HAVE_FUNCTION_DESCRIPTORS */ 294 295 #endif /* _RTLD_SOURCE */ 296 297 #endif /* RTLD_H */ 298
Indexes created Tue Sep 30 11:09:46 GMT 2025