1/*	$OpenBSD: link.h,v 1.15 2013/10/19 09:00:18 deraadt 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#endif
41
42/*
43 * A `Shared Object Descriptor' describes a shared object that is needed
44 * to complete the link edit process of the object containing it.
45 * A list of such objects (chained through `sod_next') is pointed at
46 * by `sdt_sods' in the section_dispatch_table structure.
47 */
48
49struct sod {	/* Shared Object Descriptor */
50	long		sod_name;	/* name (relative to load address) */
51	unsigned int 	sod_library : 1,/* Searched for by library rules */
52			sod_reserved : 31;
53	short		sod_major;	/* major version number */
54	short		sod_minor;	/* minor version number */
55	long		sod_next;	/* next sod */
56};
57
58/*
59 * `Shared Object Map's are used by the run-time link editor (ld.so) to
60 * keep track of all shared objects loaded into a process' address space.
61 * These structures are only used at run-time and do not occur within
62 * the text or data segment of an executable or shared library.
63 */
64struct so_map {		/* Shared Object Map */
65	caddr_t		som_addr;	/* Address at which object mapped */
66	char 		*som_path;	/* Path to mmap'ed file */
67	struct so_map	*som_next;	/* Next map in chain */
68	struct sod	*som_sod;	/* Sod responsible for this map */
69	caddr_t		som_sodbase;	/* Base address of this sod */
70	unsigned int	som_write : 1;	/* Text is currently writable */
71	struct _dynamic	*som_dynamic;	/* _dynamic structure */
72	caddr_t		som_spd;	/* Private data */
73};
74
75
76/*
77 *	Debug rendezvous struct. Pointer to this is set up in the
78 *	target code pointed by the DT_DEBUG tag. If it is
79 *	defined.
80 */
81struct r_debug {
82	int	r_version;		/* Protocol version. */
83	struct link_map *r_map;		/* Head of list of loaded objects. */
84
85	/*
86	 * This is the address of a function internal to the run-time linker,
87	 * that will always be called when the linker begins to map in a
88	 * library or unmap it, and again when the mapping change is complete.
89	 * The debugger can set a breakpoint at this address if it wants to
90	 * notice shared object mapping changes.
91	 */
92	unsigned long r_brk;
93	enum {
94		/*
95		 * This state value describes the mapping change taking place
96		 * when the `r_brk' address is called.
97		 */
98		RT_CONSISTENT,		/* Mapping change is complete.  */
99		RT_ADD,			/* Adding a new object.  */
100		RT_DELETE		/* Removing an object mapping.  */
101	} r_state;
102
103	unsigned long r_ldbase;		/* Base address the linker is loaded at.  */
104};
105
106
107
108/*
109 * Maximum number of recognized shared object version numbers.
110 */
111#define MAXDEWEY	8
112
113/*
114 * Header of the hints file.
115 */
116struct hints_header {
117	long		hh_magic;
118#define HH_MAGIC	011421044151
119	long		hh_version;	/* Interface version number */
120#define LD_HINTS_VERSION_1	1
121#define LD_HINTS_VERSION_2	2
122	long		hh_hashtab;	/* Location of hash table */
123	long		hh_nbucket;	/* Number of buckets in hashtab */
124	long		hh_strtab;	/* Location of strings */
125	long		hh_strtab_sz;	/* Size of strings */
126	long		hh_ehints;	/* End of hints (max offset in file) */
127	long		hh_dirlist;	/* Colon-separated list of srch dirs */
128};
129
130#define HH_BADMAG(hdr)	((hdr).hh_magic != HH_MAGIC)
131
132/*
133 * Hash table element in hints file.
134 */
135struct hints_bucket {
136	/* namex and pathx are indices into the string table */
137	int		hi_namex;		/* Library name */
138	int		hi_pathx;		/* Full path */
139	int		hi_dewey[MAXDEWEY];	/* The versions */
140	int		hi_ndewey;		/* Number of version numbers */
141#define hi_major hi_dewey[0]
142#define hi_minor hi_dewey[1]
143	int		hi_next;		/* Next in this bucket */
144};
145
146#define _PATH_LD_HINTS		"/var/run/ld.so.hints"
147
148#endif /* _LINK_H_ */
149
150