resolve.h revision 1.103 
1/*	$OpenBSD: resolve.h,v 1.103 2022/12/04 15:42:07 deraadt Exp $ */
2
3/*
4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 */
28
29#ifndef _RESOLVE_H_
30#define _RESOLVE_H_
31
32#include <sys/queue.h>
33#include <dlfcn.h>
34#include <link.h>
35#include <tib.h>
36
37#define __relro		__attribute__((section(".data.rel.ro")))
38
39#ifndef __boot
40# if DO_CLEAN_BOOT
41#  define __boot	__attribute__((section(".boot.text")))
42#  define __boot_data	__attribute__((section(".boot.data")))
43# else
44#  define __boot
45#  define __boot_data
46# endif
47#endif
48
49/* Number of low tags that are used saved internally (0 .. DT_NUM-1) */
50#define DT_NUM	(DT_RELR + 1)
51
52struct load_list {
53	struct load_list *next;
54	void		*start;
55	size_t		size;
56	int		prot;
57	Elf_Addr	moff;
58	long		foff;
59};
60
61typedef void initarrayfunc(int, const char **, char **, dl_cb_cb *);
62typedef void initfunc(void);	/* also fini and fini_array functions */
63
64/* Alpha uses 8byte entries for DT_HASH */
65#ifdef __alpha__
66typedef uint64_t Elf_Hash_Word;
67#else
68typedef uint32_t Elf_Hash_Word;
69#endif
70
71typedef struct elf_object elf_object_t;
72
73struct object_vector {
74	int		len;
75	int		alloc;
76	elf_object_t 	**vec;
77};
78void	object_vec_grow(struct object_vector *_vec, int _more);
79
80struct mutate {
81	vaddr_t start;
82	vaddr_t end;
83	int valid;
84};
85
86/*
87 *  Structure describing a loaded object.
88 *  The head of this struct must be compatible
89 *  with struct link_map in <link_elf.h>
90 */
91struct elf_object {
92	Elf_Addr obj_base;		/* object's address '0' base */
93	char	*load_name;		/* Pointer to object name */
94	Elf_Dyn *load_dyn;		/* Pointer to object dynamic data */
95	struct elf_object *next;
96	struct elf_object *prev;
97/* End struct link_map compatible */
98	Elf_Addr load_base;		/* Base address of loadable segments */
99
100	struct load_list *load_list;
101
102	u_int32_t  load_size;
103
104	union {
105		u_long		info[DT_NUM + DT_PROCNUM];
106		struct {
107			Elf_Addr	null;		/* Not used */
108			Elf_Addr	needed;		/* Not used */
109			Elf_Addr	pltrelsz;
110			Elf_Addr	*pltgot;
111			Elf_Addr	*hash;
112			const char	*strtab;
113			const Elf_Sym	*symtab;
114			Elf_RelA	*rela;
115			Elf_Addr	relasz;
116			Elf_Addr	relaent;
117			Elf_Addr	strsz;
118			Elf_Addr	syment;
119			initfunc	*init;
120			initfunc	*fini;
121			const char	*soname;
122			const char	*rpath;
123			Elf_Addr	symbolic;
124			Elf_Rel		*rel;
125			Elf_Addr	relsz;
126			Elf_Addr	relent;
127			Elf_Addr	pltrel;
128			Elf_Addr	debug;
129			Elf_Addr	textrel;
130			Elf_Addr	jmprel;
131			Elf_Addr	bind_now;
132			initarrayfunc	**init_array;
133			initfunc	**fini_array;
134			Elf_Addr	init_arraysz;
135			Elf_Addr	fini_arraysz;
136			const char	*runpath;
137			Elf_Addr	flags;
138			Elf_Addr	encoding;
139			initarrayfunc	**preinit_array;
140			Elf_Addr	preinit_arraysz;
141			Elf_Addr	unassigned;
142			Elf_Addr	relrsz;
143			Elf_Relr	*relr;
144		} u;
145	} Dyn;
146#define dyn Dyn.u
147
148	Elf_Addr	relacount;	/* DT_RELACOUNT */
149	Elf_Addr	relcount;	/* DT_RELCOUNT */
150
151	int		status;
152#define	STAT_RELOC_DONE		0x001
153#define	STAT_GOT_DONE		0x002
154#define	STAT_INIT_DONE		0x004
155#define	STAT_FINI_DONE		0x008
156#define	STAT_FINI_READY		0x010
157#define	STAT_UNLOADED		0x020
158#define	STAT_NODELETE		0x040
159#define	STAT_GNU_HASH		0x080
160#define	STAT_VISIT_INITFIRST	0x100
161#define	STAT_VISIT_INIT		0x200
162
163	Elf_Phdr	*phdrp;
164	int		phdrc;
165
166	int		obj_type;
167#define	OBJTYPE_LDR	1
168#define	OBJTYPE_EXE	2
169#define	OBJTYPE_LIB	3
170#define	OBJTYPE_DLO	4
171	int		obj_flags;	/* c.f. <sys/exec_elf.h> DF_1_* */
172	int		nodelete;
173
174	/* shared by ELF and GNU hash */
175	u_int32_t	nbuckets;
176	u_int32_t	nchains;	/* really, number of symbols */
177	union {
178		struct {
179			/* specific to ELF hash */
180			const Elf_Hash_Word	*buckets;
181			const Elf_Hash_Word	*chains;
182		} u_elf;
183		struct {
184			/* specific to GNU hash */
185			const Elf_Word		*buckets;
186			const Elf_Word		*chains;
187			const Elf_Addr		*bloom;
188			Elf_Word		mask_bm;
189			Elf_Word		shift2;
190			Elf_Word		symndx;
191		} u_gnu;
192	} hash_u;
193#define buckets_elf	hash_u.u_elf.buckets
194#define chains_elf	hash_u.u_elf.chains
195#define buckets_gnu	hash_u.u_gnu.buckets
196#define chains_gnu	hash_u.u_gnu.chains
197#define bloom_gnu	hash_u.u_gnu.bloom
198#define mask_bm_gnu	hash_u.u_gnu.mask_bm
199#define shift2_gnu	hash_u.u_gnu.shift2
200#define symndx_gnu	hash_u.u_gnu.symndx
201
202	struct object_vector	child_vec;	/* direct dep libs of object */
203	struct object_vector	grpsym_vec;	/* ordered complete dep list */
204	TAILQ_HEAD(,dep_node)	grpref_list;	/* refs to other load groups */
205
206	int		refcount;	/* dep libs only */
207	int		opencount;	/* # dlopen() & exe */
208	int		grprefcount;	/* load group refs */
209#define OBJECT_REF_CNT(object) \
210    ((object->refcount + object->opencount + object->grprefcount))
211#define OBJECT_DLREF_CNT(object) \
212    ((object->opencount + object->grprefcount))
213
214	/* object that caused this module to be loaded, used in symbol lookup */
215	elf_object_t	*load_object;
216	struct sod	sod;
217
218	/* for object confirmation */
219	dev_t	dev;
220	ino_t inode;
221
222	/* thread local storage info */
223	Elf_Addr	tls_fsize;
224	Elf_Addr	tls_msize;
225	Elf_Addr	tls_align;
226	const void	*tls_static_data;
227	int		tls_offset;
228
229	/* relro bits */
230	Elf_Addr	relro_addr;
231	Elf_Addr	relro_size;
232
233	/* generation number of last grpsym insert on this object */
234	unsigned int grpsym_gen;
235
236	char **rpath;
237	char **runpath;
238
239	/* nonzero if trace enabled for this object */
240	int traced;
241
242#define MAXMUT 40
243	struct mutate imut[MAXMUT];
244	struct mutate mut[MAXMUT];
245};
246
247struct dep_node {
248	TAILQ_ENTRY(dep_node) next_sib;
249	elf_object_t *data;
250};
251
252
253/* Please don't rename or make hidden; gdb(1) knows about these. */
254Elf_Addr _dl_bind(elf_object_t *object, int index);
255void	_dl_debug_state(void);
256
257/* exported to the application */
258extern char *__progname;
259
260__BEGIN_HIDDEN_DECLS
261void _dl_handle_nodelete(elf_object_t *_object);
262void _dl_add_object(elf_object_t *object);
263elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp,
264    Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase,
265    const long obase);
266void	_dl_remove_object(elf_object_t *object);
267void	_dl_cleanup_objects(void);
268
269void _dl_handle_already_loaded(elf_object_t *_object, int _flags);
270elf_object_t *_dl_load_shlib(const char *, elf_object_t *,
271    int, int, int nodelete);
272elf_object_t *_dl_tryload_shlib(const char *libname, int type,
273    int flags, int nodelete);
274
275int _dl_md_reloc(elf_object_t *object, int rel, int relsz);
276int _dl_md_reloc_got(elf_object_t *object, int lazy);
277
278struct sym_res {
279	const Elf_Sym		*sym;
280	const elf_object_t	*obj;
281};
282
283struct sym_res _dl_find_symbol(const char *name, int flags,
284    const Elf_Sym *ref_sym, elf_object_t *object);
285
286/*
287 * defines for _dl_find_symbol() flag field, three bits of meaning
288 * myself	- clear: search all objects,	set: search only this object
289 * warnnotfound - clear: no warning,		set: warn if not found
290 * inplt	- clear: possible plt ref	set: real matching function.
291 *
292 * inplt - due to how ELF handles function addresses in shared libraries
293 * &func may actually refer to the plt entry in the main program
294 * rather than the actual function address in the .so file.
295 * This rather bizarre behavior is documented in the SVR4 ABI.
296 * when getting the function address to relocate a PLT entry
297 * the 'real' function address is necessary, not the possible PLT address.
298 */
299/* myself */
300#define SYM_SEARCH_ALL		0x00
301#define SYM_SEARCH_SELF		0x01
302#define SYM_SEARCH_OTHER	0x02
303#define SYM_SEARCH_NEXT		0x04
304/* warnnotfound */
305#define SYM_NOWARNNOTFOUND	0x00
306#define SYM_WARNNOTFOUND	0x10
307/* inplt */
308#define SYM_NOTPLT		0x00
309#define SYM_PLT			0x20
310
311#define SYM_DLSYM		0x40
312
313int _dl_load_dep_libs(elf_object_t *object, int flags, int booting);
314int _dl_rtld(elf_object_t *object);
315void _dl_call_init(elf_object_t *object);
316void _dl_link_child(elf_object_t *dep, elf_object_t *p);
317void _dl_link_grpsym(elf_object_t *object);
318void _dl_cache_grpsym_list_setup(elf_object_t *_object);
319void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object);
320void _dl_link_dlopen(elf_object_t *dep);
321void _dl_unlink_dlopen(elf_object_t *dep);
322void _dl_notify_unload_shlib(elf_object_t *object);
323void _dl_unload_shlib(elf_object_t *object);
324void _dl_unload_dlopen(void);
325
326void _dl_run_all_dtors(void);
327
328int	_dl_match_file(struct sod *sodp, const char *name, int namelen);
329char	*_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints);
330void	_dl_load_list_free(struct load_list *load_list);
331
332void _dl_find_immutables(int type, elf_object_t *object, Elf_Ehdr *);
333void _dl_defer_mut(struct mutate *m, vaddr_t start, vsize_t len);
334void _dl_defer_immut(struct mutate *m, vaddr_t start, vsize_t len);
335void _dl_apply_immutable(elf_object_t *object);
336
337typedef void lock_cb(int);
338void	_dl_thread_kern_go(lock_cb *);
339lock_cb	*_dl_thread_kern_stop(void);
340
341char	*_dl_getenv(const char *, char **) __boot;
342void	_dl_unsetenv(const char *, char **) __boot;
343
344void	_dl_trace_setup(char **) __boot;
345void	_dl_trace_object_setup(elf_object_t *);
346int	_dl_trace_plt(const elf_object_t *, const char *);
347
348/* tib.c */
349void	_dl_allocate_tls_offsets(void) __boot;
350void	_dl_allocate_first_tib(void) __boot;
351void	_dl_set_tls(elf_object_t *_object, Elf_Phdr *_ptls, Elf_Addr _libaddr,
352	    const char *_libname);
353extern int _dl_tib_static_done;
354
355extern elf_object_t *_dl_objects;
356extern int object_count;	/* how many objects are currently loaded */
357
358extern elf_object_t *_dl_loading_object;
359
360extern struct r_debug *_dl_debug_map;
361
362extern int  _dl_pagesz;
363extern int  _dl_errno;
364
365extern char **_dl_libpath;
366
367extern int _dl_bindnow;
368extern int _dl_traceld;
369extern int _dl_debug;
370
371extern char *_dl_preload;
372extern char *_dl_tracefmt1;
373extern char *_dl_tracefmt2;
374extern char *_dl_traceprog;
375
376extern void *_dl_exec_hint;
377
378extern int _dl_trust;
379
380#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0)
381
382#define	DL_NOT_FOUND		1
383#define	DL_CANT_OPEN		2
384#define	DL_NOT_ELF		3
385#define	DL_CANT_OPEN_REF	4
386#define	DL_CANT_MMAP		5
387#define	DL_NO_SYMBOL		6
388#define	DL_INVALID_HANDLE	7
389#define	DL_INVALID_CTL		8
390#define	DL_NO_OBJECT		9
391#define	DL_CANT_FIND_OBJ	10
392#define	DL_CANT_LOAD_OBJ	11
393#define	DL_INVALID_MODE		12
394
395#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1))
396#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1))
397
398/* symbol lookup cache */
399typedef struct sym_cache {
400	const elf_object_t *obj;
401	const Elf_Sym	*sym;
402	int flags;
403} sym_cache;
404
405TAILQ_HEAD(dlochld, dep_node);
406extern struct dlochld _dlopened_child_list;
407__END_HIDDEN_DECLS
408
409#endif /* _RESOLVE_H_ */
410