rtld.h revision 1.57
1 /* $NetBSD: rtld.h,v 1.57 2002/09/24 20:23:12 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 extern int _rtld_pagesz; 54 55 #define round_down(x) ((x) & ~(_rtld_pagesz - 1)) 56 #define round_up(x) round_down((x) + _rtld_pagesz - 1) 57 58 #define NEW(type) ((type *) xmalloc(sizeof(type))) 59 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 60 61 #endif /* _RTLD_SOURCE */ 62 63 /* 64 * C++ has mandated the use of the following keywords for its new boolean 65 * type. We might as well follow their lead. 66 */ 67 typedef enum { 68 false = 0, 69 true = 1 70 } bool; 71 72 struct Struct_Obj_Entry; 73 74 typedef struct Struct_Objlist_Entry { 75 SIMPLEQ_ENTRY(Struct_Objlist_Entry) link; 76 struct Struct_Obj_Entry *obj; 77 } Objlist_Entry; 78 79 typedef SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 80 81 typedef struct Struct_Needed_Entry { 82 struct Struct_Needed_Entry *next; 83 struct Struct_Obj_Entry *obj; 84 unsigned long name; /* Offset of name in string table */ 85 } Needed_Entry; 86 87 typedef struct _rtld_search_path_t { 88 struct _rtld_search_path_t *sp_next; 89 const char *sp_path; 90 size_t sp_pathlen; 91 } Search_Path; 92 93 94 #define RTLD_MAX_ENTRY 10 95 #define RTLD_MAX_LIBRARY 4 96 #define RTLD_MAX_CTL 2 97 typedef struct _rtld_library_xform_t { 98 struct _rtld_library_xform_t *next; 99 char *name; 100 int ctl[RTLD_MAX_CTL]; 101 int ctltype[RTLD_MAX_CTL]; 102 int ctlmax; 103 struct { 104 char *value; 105 char *library[RTLD_MAX_LIBRARY]; 106 } entry[RTLD_MAX_ENTRY]; 107 } Library_Xform; 108 109 /* 110 * Shared object descriptor. 111 * 112 * Items marked with "(%)" are dynamically allocated, and must be freed 113 * when the structure is destroyed. 114 */ 115 116 #define RTLD_MAGIC 0xd550b87a 117 #define RTLD_VERSION 1 118 119 typedef struct Struct_Obj_Entry { 120 Elf32_Word magic; /* Magic number (sanity check) */ 121 Elf32_Word version; /* Version number of struct format */ 122 123 struct Struct_Obj_Entry *next; 124 char *path; /* Pathname of underlying file (%) */ 125 int refcount; 126 int dl_refcount; /* Number of times loaded by dlopen */ 127 128 /* These items are computed by map_object() or by digest_phdr(). */ 129 caddr_t mapbase; /* Base address of mapped region */ 130 size_t mapsize; /* Size of mapped region in bytes */ 131 size_t textsize; /* Size of text segment in bytes */ 132 Elf_Addr vaddrbase; /* Base address in shared object file */ 133 caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ 134 Elf_Dyn *dynamic; /* Dynamic section */ 135 caddr_t entry; /* Entry point */ 136 const Elf_Phdr *phdr; /* Program header if mapped, ow NULL */ 137 size_t phsize; /* Size of program header in bytes */ 138 139 /* Items from the dynamic section. */ 140 Elf_Addr *pltgot; /* PLTGOT table */ 141 const Elf_Rel *rel; /* Relocation entries */ 142 const Elf_Rel *rellim; /* Limit of Relocation entries */ 143 const Elf_Rela *rela; /* Relocation entries */ 144 const Elf_Rela *relalim; /* Limit of Relocation entries */ 145 const Elf_Rel *pltrel; /* PLT relocation entries */ 146 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 147 const Elf_Rela *pltrela; /* PLT relocation entries */ 148 const Elf_Rela *pltrelalim; /* Limit of PLT relocation entries */ 149 const Elf_Sym *symtab; /* Symbol table */ 150 const char *strtab; /* String table */ 151 unsigned long strsize; /* Size in bytes of string table */ 152 #if defined(__mips__) 153 Elf_Word local_gotno; /* Number of local GOT entries */ 154 Elf_Word symtabno; /* Number of dynamic symbols */ 155 Elf_Word gotsym; /* First dynamic symbol in GOT */ 156 #endif 157 158 const Elf_Word *buckets; /* Hash table buckets array */ 159 unsigned long nbuckets; /* Number of buckets */ 160 const Elf_Word *chains; /* Hash table chain array */ 161 unsigned long nchains; /* Number of chains */ 162 163 Search_Path *rpaths; /* Search path specified in object */ 164 Needed_Entry *needed; /* Shared objects needed by this (%) */ 165 166 void (*init) /* Initialization function to call */ 167 __P((void)); 168 void (*fini) /* Termination function to call */ 169 __P((void)); 170 171 /* Entry points for dlopen() and friends. */ 172 void *(*dlopen) __P((const char *, int)); 173 void *(*dlsym) __P((void *, const char *)); 174 char *(*dlerror) __P((void)); 175 int (*dlclose) __P((void *)); 176 int (*dladdr) __P((const void *, Dl_info *)); 177 178 u_int32_t mainprog:1, /* True if this is the main program */ 179 rtld:1, /* True if this is the dynamic linker */ 180 textrel:1, /* True if there are relocations to 181 * text seg */ 182 symbolic:1, /* True if generated with 183 * "-Bsymbolic" */ 184 printed:1, /* True if ldd has printed it */ 185 isdynamic:1; /* True if this is a pure PIC object */ 186 187 struct link_map linkmap; /* for GDB */ 188 189 /* These items are computed by map_object() or by digest_phdr(). */ 190 const char *interp; /* Pathname of the interpreter, if any */ 191 Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 192 Objlist dagmembers; /* DAG has these members (%) */ 193 dev_t dev; /* Object's filesystem's device */ 194 ino_t ino; /* Object's inode number */ 195 } Obj_Entry; 196 197 #if defined(_RTLD_SOURCE) 198 199 extern struct r_debug _rtld_debug; 200 extern Search_Path *_rtld_default_paths; 201 extern Obj_Entry *_rtld_objlist; 202 extern Obj_Entry **_rtld_objtail; 203 extern Obj_Entry *_rtld_objmain; 204 extern Obj_Entry _rtld_objself; 205 extern Search_Path *_rtld_paths; 206 extern Library_Xform *_rtld_xforms; 207 extern bool _rtld_trust; 208 extern const char *_rtld_error_message; 209 extern Objlist _rtld_list_global; 210 extern Objlist _rtld_list_main; 211 extern Elf_Sym _rtld_sym_zero; 212 213 /* rtld.c */ 214 void _rtld_error __P((const char *, ...)) 215 __attribute__((__format__(__printf__,1,2))); 216 void _rtld_die __P((void)); 217 char *_rtld_dlerror __P((void)); 218 void *_rtld_dlopen __P((const char *, int)); 219 void *_rtld_objmain_sym __P((const char *)); 220 void *_rtld_dlsym __P((void *, const char *)); 221 int _rtld_dlclose __P((void *)); 222 int _rtld_dladdr __P((const void *, Dl_info *)); 223 void _rtld_debug_state __P((void)); 224 void _rtld_linkmap_add __P((Obj_Entry *)); 225 void _rtld_linkmap_delete __P((Obj_Entry *)); 226 void _rtld_objlist_add __P((Objlist *, Obj_Entry *)); 227 Objlist_Entry *_rtld_objlist_find __P((Objlist *, const Obj_Entry *)); 228 229 /* headers.c */ 230 void _rtld_digest_dynamic __P((Obj_Entry *)); 231 Obj_Entry *_rtld_digest_phdr __P((const Elf_Phdr *, int, caddr_t)); 232 233 /* load.c */ 234 Obj_Entry *_rtld_load_object __P((char *, int)); 235 int _rtld_load_needed_objects __P((Obj_Entry *, int)); 236 int _rtld_preload __P((const char *)); 237 238 /* path.c */ 239 void _rtld_add_paths __P((Search_Path **, const char *)); 240 void _rtld_process_hints __P((Search_Path **, Library_Xform **, const char *)); 241 242 /* reloc.c */ 243 int _rtld_do_copy_relocations __P((const Obj_Entry *)); 244 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 245 int _rtld_relocate_objects __P((Obj_Entry *, bool, bool)); 246 int _rtld_relocate_nonplt_objects __P((const Obj_Entry *, bool)); 247 int _rtld_relocate_plt_lazy __P((const Obj_Entry *)); 248 int _rtld_relocate_plt_object __P((const Obj_Entry *, const Elf_Rela *, 249 caddr_t *)); 250 int _rtld_relocate_plt_objects __P((const Obj_Entry *)); 251 void _rtld_setup_pltgot __P((const Obj_Entry *)); 252 253 /* search.c */ 254 Obj_Entry *_rtld_load_library __P((const char *, const Obj_Entry *, int)); 255 256 /* symbol.c */ 257 unsigned long _rtld_elf_hash __P((const char *)); 258 const Elf_Sym *_rtld_symlook_obj __P((const char *, unsigned long, 259 const Obj_Entry *, bool)); 260 const Elf_Sym *_rtld_find_symdef __P((unsigned long, const Obj_Entry *, 261 const Obj_Entry **, bool)); 262 const Elf_Sym *_rtld_symlook_list(const char *, unsigned long, 263 Objlist *, const Obj_Entry **, bool); 264 265 /* map_object.c */ 266 Obj_Entry *_rtld_map_object __P((char *, int, const struct stat *)); 267 void _rtld_obj_free(Obj_Entry *); 268 Obj_Entry *_rtld_obj_new(void); 269 270 /* function descriptors */ 271 #ifdef __HAVE_FUNCTION_DESCRIPTORS 272 Elf_Addr _rtld_function_descriptor_alloc __P((const Obj_Entry *, 273 const Elf_Sym *, Elf_Addr)); 274 const void *_rtld_function_descriptor_function __P((const void *)); 275 #endif /* __HAVE_FUNCTION_DESCRIPTORS */ 276 277 #endif /* _RTLD_SOURCE */ 278 279 #endif /* RTLD_H */ 280
Indexes created Tue Sep 30 20:09:53 GMT 2025