rtld.h revision 35529 
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++. */
45typedef unsigned char bool;
46#define false	0
47#define true	1
48
49struct Struct_Obj_Entry;
50
51typedef 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 */
63typedef 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
119extern void _rtld_error(const char *, ...);
120extern Obj_Entry *map_object(int);
121extern void *xcalloc(size_t);
122extern void *xmalloc(size_t);
123extern char *xstrdup(const char *);
124
125#endif /* } */
126