rtld.h revision 45501
185909Simp/*- 285909Simp * Copyright 1996-1998 John D. Polstra. 3122116Sbde * All rights reserved. 4122116Sbde * 5122116Sbde * Redistribution and use in source and binary forms, with or without 685909Simp * modification, are permitted provided that the following conditions 785909Simp * are met: 885909Simp * 1. Redistributions of source code must retain the above copyright 985909Simp * notice, this list of conditions and the following disclaimer. 1085909Simp * 2. Redistributions in binary form must reproduce the above copyright 1185909Simp * notice, this list of conditions and the following disclaimer in the 1285909Simp * documentation and/or other materials provided with the distribution. 1391512Sobrien * 14116341Smarkm * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1585909Simp * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1685909Simp * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1785909Simp * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1885909Simp * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19126890Strhodes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20126890Strhodes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21126890Strhodes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22127543Skensmith * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23127204Sobrien * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24127259Smarcel * 25127259Smarcel * $Id: rtld.h,v 1.5 1998/09/04 19:03:57 dfr Exp $ 26127543Skensmith */ 27127543Skensmith 28127204Sobrien#ifndef RTLD_H /* { */ 2985909Simp#define RTLD_H 1 30127204Sobrien 31126890Strhodes#include <sys/types.h> 32124834Sru 33126890Strhodes#include <link.h> 34124834Sru#include <elf.h> 3585909Simp#include <stddef.h> 36126890Strhodes 37126890Strhodes#include "rtld_machdep.h" 38126890Strhodes 3985909Simp#ifndef STANDARD_LIBRARY_PATH 40126890Strhodes#define STANDARD_LIBRARY_PATH "/usr/lib/elf:/usr/lib" 4185909Simp#endif 42126890Strhodes 43126890Strhodes#define NEW(type) ((type *) xmalloc(sizeof(type))) 44126890Strhodes#define CNEW(type) ((type *) xcalloc(sizeof(type))) 45126890Strhodes 46126890Strhodes/* We might as well do booleans like C++. */ 4785909Simptypedef unsigned char bool; 48126890Strhodes#define false 0 49126890Strhodes#define true 1 50126938Strhodes 5185909Simpstruct Struct_Obj_Entry; 5285909Simp 5385909Simptypedef struct Struct_Needed_Entry { 54130416Smlaier struct Struct_Needed_Entry *next; 55130416Smlaier struct Struct_Obj_Entry *obj; 56130416Smlaier unsigned long name; /* Offset of name in string table */ 5785909Simp} Needed_Entry; 5885909Simp 5985909Simp/* 60126263Smlaier * Shared object descriptor. 61126263Smlaier * 62126263Smlaier * Items marked with "(%)" are dynamically allocated, and must be freed 63116817Ssam * when the structure is destroyed. 64116817Ssam */ 65116817Ssamtypedef struct Struct_Obj_Entry { 66121613Sharti /* 67121613Sharti * These two items have to be set right for compatibility with the 68121613Sharti * original ElfKit crt1.o. 6999932Sbde */ 70122116Sbde Elf_Word magic; /* Magic number (sanity check) */ 71126890Strhodes Elf_Word version; /* Version number of struct format */ 72124834Sru 73122116Sbde struct Struct_Obj_Entry *next; 74126890Strhodes char *path; /* Pathname of underlying file (%) */ 7585909Simp int refcount; 7685909Simp int dl_refcount; /* Number of times loaded by dlopen */ 7785909Simp 7885909Simp /* These items are computed by map_object() or by digest_phdr(). */ 7999923Sbde caddr_t mapbase; /* Base address of mapped region */ 80126938Strhodes size_t mapsize; /* Size of mapped region in bytes */ 81126938Strhodes size_t textsize; /* Size of text segment in bytes */ 82126938Strhodes Elf_Addr vaddrbase; /* Base address in shared object file */ 8399932Sbde caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 84126938Strhodes const Elf_Dyn *dynamic; /* Dynamic section */ 8599932Sbde caddr_t entry; /* Entry point */ 8699932Sbde const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 87126890Strhodes size_t phsize; /* Size of program header in bytes */ 88126890Strhodes 89126890Strhodes /* Items from the dynamic section. */ 90126890Strhodes Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 91123989Sbde const Elf_Rel *rel; /* Relocation entries */ 92126890Strhodes unsigned long relsize; /* Size in bytes of relocation info */ 9399932Sbde const Elf_Rela *rela; /* Relocation entries with addend */ 94126890Strhodes unsigned long relasize; /* Size in bytes of addend relocation info */ 95126890Strhodes const Elf_Rel *pltrel; /* PLT relocation entries */ 96126890Strhodes unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 9799923Sbde const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 98126890Strhodes unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 9999923Sbde const Elf_Sym *symtab; /* Symbol table */ 10099932Sbde const char *strtab; /* String table */ 10185909Simp unsigned long strsize; /* Size in bytes of string table */ 10291002Speter 10385909Simp const Elf_Addr *buckets; /* Hash table buckets array */ 10485909Simp unsigned long nbuckets; /* Number of buckets */ 10585909Simp const Elf_Addr *chains; /* Hash table chain array */ 10685909Simp unsigned long nchains; /* Number of chains */ 107116341Smarkm 108116341Smarkm const char *rpath; /* Search path specified in object */ 109116341Smarkm Needed_Entry *needed; /* Shared objects needed by this one (%) */ 11091002Speter 11191002Speter void (*init)(void); /* Initialization function to call */ 11291002Speter void (*fini)(void); /* Termination function to call */ 113105489Smux 11485909Simp bool mainprog; /* True if this is the main program */ 115105462Smux bool rtld; /* True if this is the dynamic linker */ 116105462Smux bool textrel; /* True if there are relocations to text seg */ 11785909Simp bool symbolic; /* True if generated with "-Bsymbolic" */ 118116341Smarkm bool traced; /* Already printed in ldd trace output */ 119116341Smarkm 120131210Simp struct link_map linkmap; /* for GDB */ 121111684Sru} Obj_Entry; 12285909Simp 123111684Sru#define RTLD_MAGIC 0xd550b87a 124111684Sru#define RTLD_VERSION 1 125111684Sru 126123966Sbdeextern void _rtld_error(const char *, ...); 12789180Smsmithextern Obj_Entry *map_object(int); 12885909Simpextern void *xcalloc(size_t); 12985909Simpextern void *xmalloc(size_t); 130123966Sbdeextern char *xstrdup(const char *); 13185909Simpextern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 13285909Simp 13388893Simp/* 13488893Simp * Function declarations. 13588893Simp */ 13688893Simpint do_copy_relocations(Obj_Entry *); 13790789Sphkunsigned long elf_hash(const char *); 13890789Sphkconst Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 13990789Sphk const Obj_Entry **, bool); 14088893Simpvoid init_pltgot(Obj_Entry *); 14188893Simpint reloc_non_plt(Obj_Entry *, Obj_Entry *); 14288893Simpint reloc_plt(Obj_Entry *, bool); 14388893Simpvoid _rtld_bind_start(void); 144125772Sruconst Elf_Sym *symlook_obj(const char *, unsigned long, 14588893Simp const Obj_Entry *, bool); 146 147#endif /* } */ 148