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 * $Id: rtld.h,v 1.1.1.1 1998/03/07 19:24:35 jdp Exp $ 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 #ifndef STANDARD_LIBRARY_PATH 38 #define STANDARD_LIBRARY_PATH "/usr/lib/elf:/usr/lib" 39 #endif 40 41 #define NEW(type) ((type *) xmalloc(sizeof(type))) 42 #define CNEW(type) ((type *) xcalloc(sizeof(type))) 43 44 /* We might as well do booleans like C++. */ 45 typedef unsigned char bool; 46 #define false 0 47 #define true 1 48 49 struct Struct_Obj_Entry; 50 51 typedef struct Struct_Needed_Entry { 52 struct Struct_Needed_Entry *next; 53 struct Struct_Obj_Entry *obj; 54 unsigned long name; /* Offset of name in string table */ 55 } Needed_Entry; 56 57 /* 58 * Shared object descriptor. 59 * 60 * Items marked with "(%)" are dynamically allocated, and must be freed 61 * when the structure is destroyed. 62 */ 63 typedef struct Struct_Obj_Entry { 64 /* 65 * These two items have to be set right for compatibility with the 66 * original ElfKit crt1.o. 67 */ 68 Elf32_Word magic; /* Magic number (sanity check) */ 69 Elf32_Word version; /* Version number of struct format */ 70 71 struct Struct_Obj_Entry *next; 72 char *path; /* Pathname of underlying file (%) */ 73 int refcount; 74 int dl_refcount; /* Number of times loaded by dlopen */ 75 76 /* These items are computed by map_object() or by digest_phdr(). */ 77 caddr_t mapbase; /* Base address of mapped region */ 78 size_t mapsize; /* Size of mapped region in bytes */ 79 size_t textsize; /* Size of text segment in bytes */ 80 Elf32_Addr vaddrbase; /* Base address in shared object file */ 81 caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 82 const Elf32_Dyn *dynamic; /* Dynamic section */ 83 caddr_t entry; /* Entry point */ 84 const Elf32_Phdr *phdr; /* Program header if it is mapped, else NULL */ 85 size_t phsize; /* Size of program header in bytes */ 86 87 /* Items from the dynamic section. */ 88 Elf32_Addr *got; /* GOT table */ 89 const Elf32_Rel *rel; /* Relocation entries */ 90 unsigned long relsize; /* Size in bytes of relocation info */ 91 const Elf32_Rel *pltrel; /* PLT relocation entries */ 92 unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 93 const Elf32_Sym *symtab; /* Symbol table */ 94 const char *strtab; /* String table */ 95 unsigned long strsize; /* Size in bytes of string table */ 96 97 const Elf32_Word *buckets; /* Hash table buckets array */ 98 unsigned long nbuckets; /* Number of buckets */ 99 const Elf32_Word *chains; /* Hash table chain array */ 100 unsigned long nchains; /* Number of chains */ 101 102 const char *rpath; /* Search path specified in object */ 103 Needed_Entry *needed; /* Shared objects needed by this one (%) */ 104 105 void (*init)(void); /* Initialization function to call */ 106 void (*fini)(void); /* Termination function to call */ 107 108 bool mainprog; /* True if this is the main program */ 109 bool rtld; /* True if this is the dynamic linker */ 110 bool textrel; /* True if there are relocations to text seg */ 111 bool symbolic; /* True if generated with "-Bsymbolic" */ 112 113 struct link_map linkmap; /* for GDB */ 114 } Obj_Entry; 115 116 #define RTLD_MAGIC 0xd550b87a 117 #define RTLD_VERSION 1 118 119 extern void _rtld_error(const char *, ...); 120 extern Obj_Entry *map_object(int); 121 extern void *xcalloc(size_t); 122 extern void *xmalloc(size_t); 123 extern char *xstrdup(const char *); 124 125 #endif /* } */ 126