rtld.h revision 1.5
1 /* $NetBSD: rtld.h,v 1.5 1998/07/01 20:42:47 tv 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 #ifndef PAGESIZE 54 #define PAGESIZE CLBYTES 55 #endif 56 #define round_down(x) ((x) & ~(PAGESIZE-1)) 57 #define round_up(x) round_down((x) + PAGESIZE - 1) 58 59 #define NEW(type) ((type *) xmalloc(sizeof(type))) 60 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 61 62 /* 63 * C++ has mandated the use of the following keywords for its new boolean 64 * type. We might as well follow their lead. 65 */ 66 typedef unsigned char bool; 67 #define false 0 68 #define true 1 69 70 struct Struct_Obj_Entry; 71 72 typedef struct Struct_Needed_Entry { 73 struct Struct_Needed_Entry *next; 74 struct Struct_Obj_Entry *obj; 75 unsigned long name; /* Offset of name in string table */ 76 } Needed_Entry; 77 78 typedef struct _rtld_search_path_t { 79 struct _rtld_search_path_t *sp_next; 80 const char *sp_path; 81 size_t sp_pathlen; 82 } Search_Path; 83 84 /* 85 * Shared object descriptor. 86 * 87 * Items marked with "(%)" are dynamically allocated, and must be freed 88 * when the structure is destroyed. 89 */ 90 91 #define RTLD_MAGIC 0xd550b87a 92 #define RTLD_VERSION 1 93 94 typedef struct Struct_Obj_Entry { 95 Elf32_Word magic; /* Magic number (sanity check) */ 96 Elf32_Word version; /* Version number of struct format */ 97 98 struct Struct_Obj_Entry *next; 99 char *path; /* Pathname of underlying file (%) */ 100 int refcount; 101 int dl_refcount; /* Number of times loaded by dlopen */ 102 103 /* These items are computed by map_object() or by digest_phdr(). */ 104 caddr_t mapbase; /* Base address of mapped region */ 105 size_t mapsize; /* Size of mapped region in bytes */ 106 size_t textsize; /* Size of text segment in bytes */ 107 Elf_Addr vaddrbase; /* Base address in shared object file */ 108 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 109 Elf_Dyn *dynamic; /* Dynamic section */ 110 caddr_t entry; /* Entry point */ 111 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 112 size_t phsize; /* Size of program header in bytes */ 113 114 /* Items from the dynamic section. */ 115 Elf_Addr *pltgot; /* PLTGOT table */ 116 const Elf_Rel *rel; /* Relocation entries */ 117 const Elf_Rel *rellim; /* Limit of Relocation entries */ 118 const Elf_RelA *rela; /* Relocation entries */ 119 const Elf_RelA *relalim; /* Limit of Relocation entries */ 120 const Elf_Rel *pltrel; /* PLT relocation entries */ 121 const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ 122 const Elf_RelA *pltrela; /* PLT relocation entries */ 123 const Elf_RelA *pltrelalim; /* Limit of PLT relocation entries */ 124 const Elf_Sym *symtab; /* Symbol table */ 125 const char *strtab; /* String table */ 126 unsigned long strsize; /* Size in bytes of string table */ 127 #if defined(__mips__) 128 Elf_Word local_gotno; /* Number of local GOT entries */ 129 Elf_Word symtabno; /* Number of dynamic symbols */ 130 Elf_Word gotsym; /* First dynamic symbol in GOT */ 131 #endif 132 133 const Elf_Word *buckets; /* Hash table buckets array */ 134 unsigned long nbuckets; /* Number of buckets */ 135 const Elf_Word *chains; /* Hash table chain array */ 136 unsigned long nchains; /* Number of chains */ 137 138 Search_Path *rpaths; /* Search path specified in object */ 139 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 140 141 void (*init)(void); /* Initialization function to call */ 142 void (*fini)(void); /* Termination function to call */ 143 144 /* Entry points for dlopen() and friends. */ 145 void *(*dlopen)(const char *, int); 146 void *(*dlsym)(void *, const char *); 147 char *(*dlerror)(void); 148 int (*dlclose)(void *); 149 150 int mainprog : 1; /* True if this is the main program */ 151 int rtld : 1; /* True if this is the dynamic linker */ 152 int textrel : 1; /* True if there are relocations to text seg */ 153 int symbolic : 1; /* True if generated with "-Bsymbolic" */ 154 int printed : 1; /* True if ldd has printed it */ 155 156 struct link_map linkmap; /* for GDB */ 157 } Obj_Entry; 158 159 extern struct r_debug _rtld_debug; 160 extern Obj_Entry *_rtld_objlist; 161 extern Obj_Entry **_rtld_objtail; 162 extern Obj_Entry _rtld_objself; 163 extern Search_Path *_rtld_paths; 164 extern bool _rtld_trust; 165 extern const char *_rtld_error_message; 166 167 /* rtld_start.S */ 168 extern void _rtld_bind_start(void); 169 170 /* rtld.c */ 171 172 extern void _rtld_error(const char *, ...); 173 extern void _rtld_die(void); 174 175 extern char *_rtld_dlerror(void); 176 extern void *_rtld_dlopen(const char *, int); 177 extern void *_rtld_dlsym(void *, const char *); 178 extern int _rtld_dlclose(void *); 179 180 extern void _rtld_debug_state(void); 181 182 extern void _rtld_linkmap_add(Obj_Entry *); 183 extern void _rtld_linkmap_delete(Obj_Entry *); 184 185 /* headers.c */ 186 187 extern void _rtld_digest_dynamic(Obj_Entry *); 188 extern Obj_Entry *_rtld_digest_phdr(const Elf_Phdr *, int, caddr_t); 189 190 /* load.c */ 191 192 extern Obj_Entry *_rtld_load_object(char *path); 193 extern int _rtld_load_needed_objects(Obj_Entry *); 194 195 /* path.c */ 196 197 extern void _rtld_add_paths(Search_Path **, const char *); 198 199 /* reloc.c */ 200 extern int _rtld_do_copy_relocations(const Obj_Entry *); 201 extern caddr_t _rtld_bind(const Obj_Entry *, Elf_Word); 202 extern int _rtld_relocate_objects(Obj_Entry *, bool); 203 204 /* search.c */ 205 206 extern char *_rtld_find_library(const char *, const Obj_Entry *); 207 208 /* symbol.c */ 209 extern unsigned long _rtld_elf_hash(const char *); 210 extern const Elf_Sym *_rtld_symlook_obj(const char *, unsigned long, 211 const Obj_Entry *, bool); 212 extern const Elf_Sym *_rtld_find_symdef(const Obj_Entry *, Elf_Word, 213 const char *, const Obj_Entry *, const Obj_Entry **, bool); 214 215 /* map_object.c */ 216 extern Obj_Entry *_rtld_map_object(const char *, int); 217 218 #if defined(__mips__) 219 /* mips_reloc.c */ 220 extern void _rtld_relocate_mips_got(Obj_Entry *); 221 extern caddr_t _rtld_bind_mips (Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr); 222 #endif 223 224 #endif /* } */ 225
Indexes created Mon Sep 29 21:09:56 GMT 2025