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_ */