Annotation of src/include/link.h, Revision 1.5
1.5 ! espie 1: /* $OpenBSD: link.h,v 1.4 1999/05/18 15:50:09 espie Exp $ */
1.2 deraadt 2: /* $NetBSD: link.h,v 1.10 1996/01/09 00:00:11 pk Exp $ */
1.1 deraadt 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 withough 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: * RRS section definitions.
36: *
37: * The layout of some data structures defined in this header file is
38: * such that we can provide compatibility with the SunOS 4.x shared
39: * library scheme.
40: */
41:
42: #ifndef _LINK_H_
43: #define _LINK_H_
44:
45: /*
1.4 espie 46: * A `Shared Object Descriptor' describes a shared object that is needed
1.1 deraadt 47: * to complete the link edit process of the object containing it.
48: * A list of such objects (chained through `sod_next') is pointed at
49: * by `sdt_sods' in the section_dispatch_table structure.
50: */
51:
52: struct sod { /* Shared Object Descriptor */
53: long sod_name; /* name (relative to load address) */
54: u_int sod_library : 1, /* Searched for by library rules */
55: sod_reserved : 31;
56: short sod_major; /* major version number */
57: short sod_minor; /* minor version number */
58: long sod_next; /* next sod */
59: };
60:
61: /*
62: * `Shared Object Map's are used by the run-time link editor (ld.so) to
63: * keep track of all shared objects loaded into a process' address space.
64: * These structures are only used at run-time and do not occur within
65: * the text or data segment of an executable or shared library.
66: */
67: struct so_map { /* Shared Object Map */
68: caddr_t som_addr; /* Address at which object mapped */
69: char *som_path; /* Path to mmap'ed file */
70: struct so_map *som_next; /* Next map in chain */
71: struct sod *som_sod; /* Sod responsible for this map */
72: caddr_t som_sodbase; /* Base address of this sod */
73: u_int som_write : 1; /* Text is currently writable */
74: struct _dynamic *som_dynamic; /* _dynamic structure */
75: caddr_t som_spd; /* Private data */
76: };
77:
78: /*
79: * Symbol description with size. This is simply an `nlist' with
80: * one field (nz_size) added.
81: * Used to convey size information on items in the data segment
82: * of shared objects. An array of these live in the shared object's
83: * text segment and is addressed by the `sdt_nzlist' field.
84: */
85: struct nzlist {
86: struct nlist nlist;
87: u_long nz_size;
88: #define nz_un nlist.n_un
89: #define nz_strx nlist.n_un.n_strx
90: #define nz_name nlist.n_un.n_name
91: #define nz_type nlist.n_type
92: #define nz_value nlist.n_value
93: #define nz_desc nlist.n_desc
94: #define nz_other nlist.n_other
95: };
96:
97: #define N_AUX(p) ((p)->n_other & 0xf)
98: #define N_BIND(p) (((unsigned int)(p)->n_other >> 4) & 0xf)
99: #define N_OTHER(r, v) (((unsigned int)(r) << 4) | ((v) & 0xf))
100:
101: #define AUX_OBJECT 1
102: #define AUX_FUNC 2
103: /*#define BIND_LOCAL 0 not used */
104: /*#define BIND_GLOBAL 1 not used */
105: #define BIND_WEAK 2
106:
107:
108: /*
109: * The `section_dispatch_table' structure contains offsets to various data
110: * structures needed to do run-time relocation.
111: */
112: struct section_dispatch_table {
113: struct so_map *sdt_loaded; /* List of loaded objects */
114: long sdt_sods; /* List of shared objects descriptors */
115: long sdt_paths; /* Library search paths */
116: long sdt_got; /* Global offset table */
117: long sdt_plt; /* Procedure linkage table */
118: long sdt_rel; /* Relocation table */
119: long sdt_hash; /* Symbol hash table */
120: long sdt_nzlist; /* Symbol table itself */
121: long sdt_filler2; /* Unused (was: stab_hash) */
122: long sdt_buckets; /* Number of hash buckets */
123: long sdt_strings; /* Symbol strings */
124: long sdt_str_sz; /* Size of symbol strings */
125: long sdt_text_sz; /* Size of text area */
126: long sdt_plt_sz; /* Size of procedure linkage table */
127: };
128:
129: /*
130: * RRS symbol hash table, addressed by `sdt_hash' in section_dispatch_table.
131: * Used to quickly lookup symbols of the shared object by hashing
132: * on the symbol's name. `rh_symbolnum' is the index of the symbol
133: * in the shared object's symbol list (`sdt_nzlist'), `rh_next' is
134: * the next symbol in the hash bucket (in case of collisions).
135: */
136: struct rrs_hash {
137: int rh_symbolnum; /* Symbol number */
138: int rh_next; /* Next hash entry */
139: };
140:
141: /*
142: * `rt_symbols' is used to keep track of run-time allocated commons
143: * and data items copied from shared objects.
144: */
145: struct rt_symbol {
146: struct nzlist *rt_sp; /* The symbol */
147: struct rt_symbol *rt_next; /* Next in linear list */
148: struct rt_symbol *rt_link; /* Next in bucket */
149: caddr_t rt_srcaddr; /* Address of "master" copy */
150: struct so_map *rt_smp; /* Originating map */
151: };
152:
153: /*
154: * Debugger interface structure.
155: */
156: struct so_debug {
157: int dd_version; /* Version # of interface */
158: int dd_in_debugger; /* Set when run by debugger */
159: int dd_sym_loaded; /* Run-time linking brought more
160: symbols into scope */
161: char *dd_bpt_addr; /* Address of rtld-generated bpt */
162: int dd_bpt_shadow; /* Original contents of bpt */
163: struct rt_symbol *dd_cc; /* Allocated commons/copied data */
164: };
165:
166: /*
167: * Entry points into ld.so - user interface to the run-time linker.
168: */
169: struct ld_entry {
1.5 ! espie 170: void *(*dlopen) __P((const char *, int));
1.1 deraadt 171: int (*dlclose) __P((void *));
1.5 ! espie 172: void *(*dlsym) __P((void *, const char *));
1.1 deraadt 173: int (*dlctl) __P((void *, int, void *));
174: void (*dlexit) __P((void));
175: void (*dlrsrvd[3]) __P((void));
176: };
177:
178: /*
179: * This is the structure pointed at by the __DYNAMIC symbol if an
180: * executable requires the attention of the run-time link editor.
181: * __DYNAMIC is given the value zero if no run-time linking needs to
182: * be done (it is always present in shared objects).
183: * The union `d_un' provides for different versions of the dynamic
184: * linking mechanism (switched on by `d_version'). The last version
185: * used by Sun is 3. We leave some room here and go to version number
186: * 8 for NetBSD, the main difference lying in the support for the
187: * `nz_list' type of symbols.
188: */
189:
190: struct _dynamic {
191: int d_version; /* version # of this interface */
192: struct so_debug *d_debug;
193: union {
194: struct section_dispatch_table *d_sdt;
195: } d_un;
196: struct ld_entry *d_entry; /* compat - now in crt_ldso */
197: };
198:
199: #define LD_VERSION_SUN (3)
200: #define LD_VERSION_BSD (8)
201: #define LD_VERSION_NZLIST_P(v) ((v) >= 8)
202:
203: #define LD_GOT(x) ((x)->d_un.d_sdt->sdt_got)
204: #define LD_PLT(x) ((x)->d_un.d_sdt->sdt_plt)
205: #define LD_REL(x) ((x)->d_un.d_sdt->sdt_rel)
206: #define LD_SYMBOL(x) ((x)->d_un.d_sdt->sdt_nzlist)
207: #define LD_HASH(x) ((x)->d_un.d_sdt->sdt_hash)
208: #define LD_STRINGS(x) ((x)->d_un.d_sdt->sdt_strings)
209: #define LD_NEED(x) ((x)->d_un.d_sdt->sdt_sods)
210: #define LD_BUCKETS(x) ((x)->d_un.d_sdt->sdt_buckets)
211: #define LD_PATHS(x) ((x)->d_un.d_sdt->sdt_paths)
212:
213: #define LD_GOTSZ(x) ((x)->d_un.d_sdt->sdt_plt - (x)->d_un.d_sdt->sdt_got)
214: #define LD_RELSZ(x) ((x)->d_un.d_sdt->sdt_hash - (x)->d_un.d_sdt->sdt_rel)
215: #define LD_HASHSZ(x) ((x)->d_un.d_sdt->sdt_nzlist - (x)->d_un.d_sdt->sdt_hash)
216: #define LD_STABSZ(x) ((x)->d_un.d_sdt->sdt_strings - (x)->d_un.d_sdt->sdt_nzlist)
217: #define LD_PLTSZ(x) ((x)->d_un.d_sdt->sdt_plt_sz)
218: #define LD_STRSZ(x) ((x)->d_un.d_sdt->sdt_str_sz)
219: #define LD_TEXTSZ(x) ((x)->d_un.d_sdt->sdt_text_sz)
220:
221: /*
222: * Interface to ld.so
223: */
224: struct crt_ldso {
225: int crt_ba; /* Base address of ld.so */
226: int crt_dzfd; /* "/dev/zero" file decriptor (SunOS) */
227: int crt_ldfd; /* ld.so file descriptor */
228: struct _dynamic *crt_dp; /* Main's __DYNAMIC */
229: char **crt_ep; /* environment strings */
230: caddr_t crt_bp; /* Breakpoint if run from debugger */
231: char *crt_prog; /* Program name (v3) */
232: char *crt_ldso; /* Link editor name (v4) */
233: struct ld_entry *crt_ldentry; /* dl*() access (v4) */
234: };
235:
236: /*
237: * Version passed from crt0 to ld.so (1st argument to _rtld()).
238: */
239: #define CRT_VERSION_SUN 1
240: #define CRT_VERSION_BSD_2 2
241: #define CRT_VERSION_BSD_3 3
242: #define CRT_VERSION_BSD_4 4
243:
244:
245: /*
246: * Maximum number of recognized shared object version numbers.
247: */
248: #define MAXDEWEY 8
249:
250: /*
251: * Header of the hints file.
252: */
253: struct hints_header {
254: long hh_magic;
255: #define HH_MAGIC 011421044151
256: long hh_version; /* Interface version number */
257: #define LD_HINTS_VERSION_1 1
1.2 deraadt 258: #define LD_HINTS_VERSION_2 2
1.1 deraadt 259: long hh_hashtab; /* Location of hash table */
260: long hh_nbucket; /* Number of buckets in hashtab */
261: long hh_strtab; /* Location of strings */
262: long hh_strtab_sz; /* Size of strings */
263: long hh_ehints; /* End of hints (max offset in file) */
1.2 deraadt 264: long hh_dirlist; /* Colon-separated list of srch dirs */
1.1 deraadt 265: };
266:
267: #define HH_BADMAG(hdr) ((hdr).hh_magic != HH_MAGIC)
268:
269: /*
270: * Hash table element in hints file.
271: */
272: struct hints_bucket {
273: /* namex and pathx are indices into the string table */
274: int hi_namex; /* Library name */
275: int hi_pathx; /* Full path */
276: int hi_dewey[MAXDEWEY]; /* The versions */
277: int hi_ndewey; /* Number of version numbers */
278: #define hi_major hi_dewey[0]
279: #define hi_minor hi_dewey[1]
280: int hi_next; /* Next in this bucket */
281: };
282:
283: #define _PATH_LD_HINTS "/var/run/ld.so.hints"
284:
285: #endif /* _LINK_H_ */
286:
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