rtld.h revision 1.4
1 /* $NetBSD: rtld.h,v 1.4 1998/03/25 04:13:02 mhitch 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 1 36 37 #include <stddef.h> 38 #include <sys/param.h> 39 #include <sys/types.h> 40 #include <sys/exec_elf.h> 41 #include "rtldenv.h" 42 #include "link.h" 43 44 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib:/usr/local/lib" 45 46 #if 0 47 #define SVR4_LIBDIR "/usr/lib" 48 #endif 49 50 #define LIBDIRLEN (sizeof LIBDIR - 1) 51 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 52 53 #define PAGESIZE CLBYTES 54 #define round_down(x) ((x) & ~(PAGESIZE-1)) 55 #define round_up(x) round_down((x) + PAGESIZE - 1) 56 57 #define NEW(type) ((type *) xmalloc(sizeof(type))) 58 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 59 60 /* 61 * C++ has mandated the use of the following keywords for its new boolean 62 * type. We might as well follow their lead. 63 */ 64 typedef unsigned char bool; 65 #define false 0 66 #define true 1 67 68 struct Struct_Obj_Entry; 69 70 typedef struct Struct_Needed_Entry { 71 struct Struct_Needed_Entry *next; 72 struct Struct_Obj_Entry *obj; 73 unsigned long name; /* Offset of name in string table */ 74 } Needed_Entry; 75 76 typedef struct _rtld_search_path_t { 77 struct _rtld_search_path_t *sp_next; 78 const char *sp_path; 79 size_t sp_pathlen; 80 } Search_Path; 81 82 /* 83 * Shared object descriptor. 84 * 85 * Items marked with "(%)" are dynamically allocated, and must be freed 86 * when the structure is destroyed. 87 */ 88 89 #define RTLD_MAGIC 0xd550b87a 90 #define RTLD_VERSION 1 91 92 typedef struct Struct_Obj_Entry { 93 Elf32_Word magic; /* Magic number (sanity check) */ 94 Elf32_Word version; /* Version number of struct format */ 95 96 struct Struct_Obj_Entry *next; 97 char *path; /* Pathname of underlying file (%) */ 98 int refcount; 99 int dl_refcount; /* Number of times loaded by dlopen */ 100 101 /* These items are computed by map_object() or by digest_phdr(). */ 102 caddr_t mapbase; /* Base address of mapped region */ 103 size_t mapsize; /* Size of mapped region in bytes */ 104 size_t textsize; /* Size of text segment in bytes */ 105 Elf_Addr vaddrbase; /* Base address in shared object file */ 106 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 107 Elf_Dyn *dynamic; /* Dynamic section */ 108 caddr_t entry; /* Entry point */ 109 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 110 size_t phsize; /* Size of program header in bytes */ 111 112 /* Items from the dynamic section. */ 113 Elf_Addr *pltgot; /* PLTGOT table */ 114 const Elf_Rel *rel; /* Relocation entries */ 115 const Elf_Rel *rellim; /* Limit of Relocation entries */ 116 const Elf_RelA *rela; /* Relocation entries */ 117 const Elf_RelA *relalim; /* Limit of Relocation entries */ 118 const Elf_Rel *pltrel; /* PLT relocation entries */ 119 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 120 const Elf_RelA *pltrela; /* PLT relocation entries */ 121 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 122 const Elf_Sym *symtab; /* Symbol table */ 123 const char *strtab; /* String table */ 124 unsigned long strsize; /* Size in bytes of string table */ 125 #if defined(__mips__) 126 Elf_Word local_gotno; /* Number of local GOT entries */ 127 Elf_Word symtabno; /* Number of dynamic symbols */ 128 Elf_Word gotsym; /* First dynamic symbol in GOT */ 129 #endif 130 131 const Elf_Word *buckets; /* Hash table buckets array */ 132 unsigned long nbuckets; /* Number of buckets */ 133 const Elf_Word *chains; /* Hash table chain array */ 134 unsigned long nchains; /* Number of chains */ 135 136 Search_Path *rpaths; /* Search path specified in object */ 137 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 138 139 void (*init)(void); /* Initialization function to call */ 140 void (*fini)(void); /* Termination function to call */ 141 142 /* Entry points for dlopen() and friends. */ 143 void *(*dlopen)(const char *, int); 144 void *(*dlsym)(void *, const char *); 145 char *(*dlerror)(void); 146 int (*dlclose)(void *); 147 148 int mainprog : 1; /* True if this is the main program */ 149 int rtld : 1; /* True if this is the dynamic linker */ 150 int textrel : 1; /* True if there are relocations to text seg */ 151 int symbolic : 1; /* True if generated with "-Bsymbolic" */ 152 int printed : 1; /* True if ldd has printed it */ 153 154 struct link_map linkmap; /* for GDB */ 155 } Obj_Entry; 156 157 extern struct r_debug _rtld_debug; 158 extern Obj_Entry *_rtld_objlist; 159 extern Obj_Entry **_rtld_objtail; 160 extern Obj_Entry _rtld_objself; 161 extern Search_Path *_rtld_paths; 162 extern bool _rtld_trust; 163 extern const char *_rtld_error_message; 164 165 /* rtld_start.S */ 166 extern void _rtld_bind_start(void); 167 168 /* rtld.c */ 169 170 extern void _rtld_error(const char *, ...); 171 extern void _rtld_die(void); 172 173 extern char *_rtld_dlerror(void); 174 extern void *_rtld_dlopen(const char *, int); 175 extern void *_rtld_dlsym(void *, const char *); 176 extern int _rtld_dlclose(void *); 177 178 extern void _rtld_debug_state(void); 179 180 extern void _rtld_linkmap_add(Obj_Entry *); 181 extern void _rtld_linkmap_delete(Obj_Entry *); 182 183 /* headers.c */ 184 185 extern void _rtld_digest_dynamic(Obj_Entry *); 186 extern Obj_Entry *_rtld_digest_phdr(const Elf_Phdr *, int, caddr_t); 187 188 /* load.c */ 189 190 extern Obj_Entry *_rtld_load_object(char *path); 191 extern int _rtld_load_needed_objects(Obj_Entry *); 192 193 /* path.c */ 194 195 extern void _rtld_add_paths(Search_Path **, const char *); 196 197 /* reloc.c */ 198 extern int _rtld_do_copy_relocations(const Obj_Entry *); 199 extern caddr_t _rtld_bind(const Obj_Entry *, Elf_Word); 200 extern int _rtld_relocate_objects(Obj_Entry *, bool); 201 202 /* search.c */ 203 204 extern char *_rtld_find_library(const char *, const Obj_Entry *); 205 206 /* symbol.c */ 207 extern unsigned long _rtld_elf_hash(const char *); 208 extern const Elf_Sym *_rtld_symlook_obj(const char *, unsigned long, 209 const Obj_Entry *, bool); 210 extern const Elf_Sym *_rtld_find_symdef(const Obj_Entry *, Elf_Word, 211 const char *, const Obj_Entry *, const Obj_Entry **, bool); 212 213 /* map_object.c */ 214 extern Obj_Entry *_rtld_map_object(const char *, int); 215 216 #if defined(__mips__) 217 /* mips_reloc.c */ 218 extern void _rtld_relocate_mips_got(Obj_Entry *); 219 extern caddr_t _rtld_bind_mips (Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr); 220 #endif 221 222 #endif /* } */ 223
Indexes created Mon Sep 29 21:09:56 GMT 2025