1 /*- 2 * Copyright 1996-1998 John D. Polstra. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 * $FreeBSD$ 26 */ 27 28 #ifndef RTLD_H /* { */ 29 #define RTLD_H 1 30 31 #include <sys/types.h> 32 33 #include <link.h> 34 #include <elf.h> 35 #include <stddef.h> 36 37 #include "rtld_machdep.h" 38 39 #ifndef STANDARD_LIBRARY_PATH 40 #define STANDARD_LIBRARY_PATH "/usr/lib/elf:/usr/lib" 41 #endif 42 43 #define NEW(type) ((type *) xmalloc(sizeof(type))) 44 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 45 46 /* We might as well do booleans like C++. */ 47 typedef unsigned char bool; 48 #define false 0 49 #define true 1 50 51 struct Struct_Obj_Entry; 52 53 typedef struct Struct_Needed_Entry { 54 struct Struct_Needed_Entry *next; 55 struct Struct_Obj_Entry *obj; 56 unsigned long name; /* Offset of name in string table */ 57 } Needed_Entry; 58 59 /* 60 * Shared object descriptor. 61 * 62 * Items marked with "(%)" are dynamically allocated, and must be freed 63 * when the structure is destroyed. 64 */ 65 typedef struct Struct_Obj_Entry { 66 /* 67 * These two items have to be set right for compatibility with the 68 * original ElfKit crt1.o. 69 */ 70 Elf_Word magic; /* Magic number (sanity check) */ 71 Elf_Word version; /* Version number of struct format */ 72 73 struct Struct_Obj_Entry *next; 74 char *path; /* Pathname of underlying file (%) */ 75 int refcount; 76 int dl_refcount; /* Number of times loaded by dlopen */ 77 78 /* These items are computed by map_object() or by digest_phdr(). */ 79 caddr_t mapbase; /* Base address of mapped region */ 80 size_t mapsize; /* Size of mapped region in bytes */ 81 size_t textsize; /* Size of text segment in bytes */ 82 Elf_Addr vaddrbase; /* Base address in shared object file */ 83 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 84 const Elf_Dyn *dynamic; /* Dynamic section */ 85 caddr_t entry; /* Entry point */ 86 const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 87 size_t phsize; /* Size of program header in bytes */ 88 89 /* Items from the dynamic section. */ 90 Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 91 const Elf_Rel *rel; /* Relocation entries */ 92 unsigned long relsize; /* Size in bytes of relocation info */ 93 const Elf_Rela *rela; /* Relocation entries with addend */ 94 unsigned long relasize; /* Size in bytes of addend relocation info */ 95 const Elf_Rel *pltrel; /* PLT relocation entries */ 96 unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 97 const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 98 unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 99 const Elf_Sym *symtab; /* Symbol table */ 100 const char *strtab; /* String table */ 101 unsigned long strsize; /* Size in bytes of string table */ 102 103 const Elf_Addr *buckets; /* Hash table buckets array */ 104 unsigned long nbuckets; /* Number of buckets */ 105 const Elf_Addr *chains; /* Hash table chain array */ 106 unsigned long nchains; /* Number of chains */ 107 108 const char *rpath; /* Search path specified in object */ 109 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 110 111 void (*init)(void); /* Initialization function to call */ 112 void (*fini)(void); /* Termination function to call */ 113 114 bool mainprog; /* True if this is the main program */ 115 bool rtld; /* True if this is the dynamic linker */ 116 bool textrel; /* True if there are relocations to text seg */ 117 bool symbolic; /* True if generated with "-Bsymbolic" */ 118 bool traced; /* Already printed in ldd trace output */ 119 120 struct link_map linkmap; /* for GDB */ 121 } Obj_Entry; 122 123 #define RTLD_MAGIC 0xd550b87a 124 #define RTLD_VERSION 1 125 126 extern void _rtld_error(const char *, ...) __printflike(1, 2); 127 extern Obj_Entry *map_object(int, const char *); 128 extern void *xcalloc(size_t); 129 extern void *xmalloc(size_t); 130 extern char *xstrdup(const char *); 131 extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 132 133 /* 134 * Function declarations. 135 */ 136 int do_copy_relocations(Obj_Entry *); 137 unsigned long elf_hash(const char *); 138 const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 139 const Obj_Entry **, bool); 140 void init_pltgot(Obj_Entry *); 141 int reloc_non_plt(Obj_Entry *, Obj_Entry *); 142 int reloc_plt(Obj_Entry *, bool); 143 void _rtld_bind_start(void); 144 const Elf_Sym *symlook_obj(const char *, unsigned long, 145 const Obj_Entry *, bool); 146 147 #endif /* } */ 148