link.h revision 1.12 
1/*	$OpenBSD: link.h,v 1.12 2002/06/07 03:00:01 art Exp $	*/
2/*	$NetBSD: link.h,v 1.10 1996/01/09 00:00:11 pk Exp $	*/
3
4/*
5 * Copyright (c) 1993 Paul Kranenburg
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 Paul Kranenburg.
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
35#ifndef _LINK_H_
36#define _LINK_H_
37
38#ifdef __ELF__
39#include <link_elf.h>
40#else
41#include <link_aout.h>
42#endif
43
44/*
45 * A `Shared Object Descriptor' describes a shared object that is needed
46 * to complete the link edit process of the object containing it.
47 * A list of such objects (chained through `sod_next') is pointed at
48 * by `sdt_sods' in the section_dispatch_table structure.
49 */
50
51struct sod {	/* Shared Object Descriptor */
52	long	sod_name;		/* name (relative to load address) */
53	u_int	sod_library  : 1,	/* Searched for by library rules */
54		sod_reserved : 31;
55	short	sod_major;		/* major version number */
56	short	sod_minor;		/* minor version number */
57	long	sod_next;		/* next sod */
58};
59
60/*
61 * `Shared Object Map's are used by the run-time link editor (ld.so) to
62 * keep track of all shared objects loaded into a process' address space.
63 * These structures are only used at run-time and do not occur within
64 * the text or data segment of an executable or shared library.
65 */
66struct so_map {		/* Shared Object Map */
67	caddr_t		som_addr;	/* Address at which object mapped */
68	char 		*som_path;	/* Path to mmap'ed file */
69	struct so_map	*som_next;	/* Next map in chain */
70	struct sod	*som_sod;	/* Sod responsible for this map */
71	caddr_t		som_sodbase;	/* Base address of this sod */
72	u_int		som_write : 1;	/* Text is currently writable */
73	struct _dynamic	*som_dynamic;	/* _dynamic structure */
74	caddr_t		som_spd;	/* Private data */
75};
76
77
78/*
79 *	Debug rendezvous struct. Pointer to this is set up in the
80 *	target code pointed by the DT_DEBUG tag. If it is
81 *	defined.
82 */
83struct r_debug {
84	int	r_version;		/* Protocol version. */
85	struct link_map *r_map;		/* Head of list of loaded objects. */
86
87	/*
88	 * This is the address of a function internal to the run-time linker,
89	 * that will always be called when the linker begins to map in a
90	 * library or unmap it, and again when the mapping change is complete.
91	 * The debugger can set a breakpoint at this address if it wants to
92	 * notice shared object mapping changes.
93	 */
94	unsigned long r_brk;
95	enum {
96		/*
97		 * This state value describes the mapping change taking place
98		 * when the `r_brk' address is called.
99		 */
100		RT_CONSISTENT,		/* Mapping change is complete.  */
101		RT_ADD,			/* Adding a new object.  */
102		RT_DELETE,		/* Removing an object mapping.  */
103	} r_state;
104
105	unsigned long r_ldbase;		/* Base address the linker is loaded at.  */
106};
107
108
109
110/*
111 * Maximum number of recognized shared object version numbers.
112 */
113#define MAXDEWEY	8
114
115/*
116 * Header of the hints file.
117 */
118struct hints_header {
119	long		hh_magic;
120#define HH_MAGIC	011421044151
121	long		hh_version;	/* Interface version number */
122#define LD_HINTS_VERSION_1	1
123#define LD_HINTS_VERSION_2	2
124	long		hh_hashtab;	/* Location of hash table */
125	long		hh_nbucket;	/* Number of buckets in hashtab */
126	long		hh_strtab;	/* Location of strings */
127	long		hh_strtab_sz;	/* Size of strings */
128	long		hh_ehints;	/* End of hints (max offset in file) */
129	long		hh_dirlist;	/* Colon-separated list of srch dirs */
130};
131
132#define HH_BADMAG(hdr)	((hdr).hh_magic != HH_MAGIC)
133
134/*
135 * Hash table element in hints file.
136 */
137struct hints_bucket {
138	/* namex and pathx are indices into the string table */
139	int		hi_namex;		/* Library name */
140	int		hi_pathx;		/* Full path */
141	int		hi_dewey[MAXDEWEY];	/* The versions */
142	int		hi_ndewey;		/* Number of version numbers */
143#define hi_major hi_dewey[0]
144#define hi_minor hi_dewey[1]
145	int		hi_next;		/* Next in this bucket */
146};
147
148#define _PATH_LD_HINTS		"/var/run/ld.so.hints"
149
150#endif /* _LINK_H_ */
151
152