rtld.h revision 1.2
1 /* $NetBSD: rtld.h,v 1.2 1996/12/17 05:04:10 cgd 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 #ifdef RTLD_LOADER 43 #include "link.h" 44 #endif 45 46 #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib:/usr/local/lib" 47 48 #if 0 49 #define SVR4_LIBDIR "/usr/lib" 50 #endif 51 52 #define LIBDIRLEN (sizeof LIBDIR - 1) 53 #define SVR4_LIBDIRLEN (sizeof SVR4_LIBDIR - 1) 54 55 #define PAGESIZE CLBYTES 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 */ 127 128 const Elf_Word *buckets; /* Hash table buckets array */ 129 unsigned long nbuckets; /* Number of buckets */ 130 const Elf_Word *chains; /* Hash table chain array */ 131 unsigned long nchains; /* Number of chains */ 132 133 Search_Path *rpaths; /* Search path specified in object */ 134 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 135 136 void (*init)(void); /* Initialization function to call */ 137 void (*fini)(void); /* Termination function to call */ 138 139 /* Entry points for dlopen() and friends. */ 140 void *(*dlopen)(const char *, int); 141 void *(*dlsym)(void *, const char *); 142 char *(*dlerror)(void); 143 int (*dlclose)(void *); 144 145 int mainprog : 1; /* True if this is the main program */ 146 int rtld : 1; /* True if this is the dynamic linker */ 147 int textrel : 1; /* True if there are relocations to text seg */ 148 int symbolic : 1; /* True if generated with "-Bsymbolic" */ 149 int printed : 1; /* True if ldd has printed it */ 150 151 #ifdef RTLD_LOADER 152 struct link_map linkmap; /* for GDB */ 153 #endif 154 } Obj_Entry; 155 156 extern struct r_debug _rtld_debug; 157 extern Obj_Entry *_rtld_objlist; 158 extern Obj_Entry **_rtld_objtail; 159 extern Obj_Entry _rtld_objself; 160 extern Search_Path *_rtld_paths; 161 extern bool _rtld_trust; 162 extern const char *_rtld_error_message; 163 164 /* rtld_start.S */ 165 extern void _rtld_bind_start(void); 166 167 /* rtld.c */ 168 169 extern void _rtld_error(const char *, ...); 170 extern void _rtld_die(void); 171 172 extern char *_rtld_dlerror(void); 173 extern void *_rtld_dlopen(const char *, int); 174 extern void *_rtld_dlsym(void *, const char *); 175 extern int _rtld_dlclose(void *); 176 177 extern void _rtld_debug_state(void); 178 179 extern void _rtld_linkmap_add(Obj_Entry *); 180 extern void _rtld_linkmap_delete(Obj_Entry *); 181 182 /* headers.c */ 183 184 extern void _rtld_digest_dynamic(Obj_Entry *); 185 extern Obj_Entry *_rtld_digest_phdr(const Elf_Phdr *, int, caddr_t); 186 187 /* load.c */ 188 189 extern Obj_Entry *_rtld_load_object(char *path); 190 extern int _rtld_load_needed_objects(Obj_Entry *); 191 192 /* path.c */ 193 194 extern void _rtld_add_paths(Search_Path **, const char *); 195 196 /* reloc.c */ 197 extern int _rtld_do_copy_relocations(const Obj_Entry *); 198 extern caddr_t _rtld_bind(const Obj_Entry *, Elf_Word); 199 extern int _rtld_relocate_objects(Obj_Entry *, bool); 200 201 /* search.c */ 202 203 extern char *_rtld_find_library(const char *, const Obj_Entry *); 204 205 /* symbol.c */ 206 extern unsigned long _rtld_elf_hash(const char *); 207 extern const Elf_Sym *_rtld_symlook_obj(const char *, unsigned long, 208 const Obj_Entry *, bool); 209 extern const Elf_Sym *_rtld_find_symdef(const Obj_Entry *, Elf_Word, 210 const char *, const Obj_Entry *, const Obj_Entry **, bool); 211 212 /* map_object.c */ 213 extern Obj_Entry *_rtld_map_object(const char *, int); 214 215 #endif /* } */ 216
Indexes created Tue Sep 30 11:09:46 GMT 2025