1/* Plugin support for BFD.
2   Copyright (C) 2009-2017 Free Software Foundation, Inc.
3
4   This file is part of BFD, the Binary File Descriptor library.
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 3 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program; if not, write to the Free Software
18   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19   MA 02110-1301, USA.  */
20
21#include "sysdep.h"
22#include "bfd.h"
23
24#if BFD_SUPPORTS_PLUGINS
25
26#include <assert.h>
27#ifdef HAVE_DLFCN_H
28#include <dlfcn.h>
29#elif defined (HAVE_WINDOWS_H)
30#include <windows.h>
31#else
32#error Unknown how to handle dynamic-load-libraries.
33#endif
34#include <stdarg.h>
35#include "plugin-api.h"
36#include "plugin.h"
37#include "libbfd.h"
38#include "libiberty.h"
39#include <dirent.h>
40
41#if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
42
43#define RTLD_NOW 0      /* Dummy value.  */
44
45static void *
46dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
47{
48  return LoadLibrary (file);
49}
50
51static void *
52dlsym (void *handle, const char *name)
53{
54  return GetProcAddress (handle, name);
55}
56
57static int ATTRIBUTE_UNUSED
58dlclose (void *handle)
59{
60  FreeLibrary (handle);
61  return 0;
62}
63
64static const char *
65dlerror (void)
66{
67  return "Unable to load DLL.";
68}
69
70#endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)  */
71
72#define bfd_plugin_close_and_cleanup                  _bfd_generic_close_and_cleanup
73#define bfd_plugin_bfd_free_cached_info               _bfd_generic_bfd_free_cached_info
74#define bfd_plugin_new_section_hook                   _bfd_generic_new_section_hook
75#define bfd_plugin_get_section_contents               _bfd_generic_get_section_contents
76#define bfd_plugin_get_section_contents_in_window     _bfd_generic_get_section_contents_in_window
77#define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
78#define bfd_plugin_bfd_merge_private_bfd_data         _bfd_generic_bfd_merge_private_bfd_data
79#define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
80#define bfd_plugin_bfd_set_private_flags              _bfd_generic_bfd_set_private_flags
81#define bfd_plugin_core_file_matches_executable_p     generic_core_file_matches_executable_p
82#define bfd_plugin_bfd_is_local_label_name            _bfd_nosymbols_bfd_is_local_label_name
83#define bfd_plugin_bfd_is_target_special_symbol       ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false)
84#define bfd_plugin_get_lineno                         _bfd_nosymbols_get_lineno
85#define bfd_plugin_find_nearest_line                  _bfd_nosymbols_find_nearest_line
86#define bfd_plugin_find_line                          _bfd_nosymbols_find_line
87#define bfd_plugin_find_inliner_info                  _bfd_nosymbols_find_inliner_info
88#define bfd_plugin_get_symbol_version_string	      _bfd_nosymbols_get_symbol_version_string
89#define bfd_plugin_bfd_make_debug_symbol              _bfd_nosymbols_bfd_make_debug_symbol
90#define bfd_plugin_read_minisymbols                   _bfd_generic_read_minisymbols
91#define bfd_plugin_minisymbol_to_symbol               _bfd_generic_minisymbol_to_symbol
92#define bfd_plugin_set_arch_mach                      bfd_default_set_arch_mach
93#define bfd_plugin_set_section_contents               _bfd_generic_set_section_contents
94#define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
95#define bfd_plugin_bfd_relax_section                  bfd_generic_relax_section
96#define bfd_plugin_bfd_link_hash_table_create         _bfd_generic_link_hash_table_create
97#define bfd_plugin_bfd_link_add_symbols               _bfd_generic_link_add_symbols
98#define bfd_plugin_bfd_link_just_syms                 _bfd_generic_link_just_syms
99#define bfd_plugin_bfd_final_link                     _bfd_generic_final_link
100#define bfd_plugin_bfd_link_split_section             _bfd_generic_link_split_section
101#define bfd_plugin_bfd_gc_sections                    bfd_generic_gc_sections
102#define bfd_plugin_bfd_lookup_section_flags           bfd_generic_lookup_section_flags
103#define bfd_plugin_bfd_merge_sections                 bfd_generic_merge_sections
104#define bfd_plugin_bfd_is_group_section               bfd_generic_is_group_section
105#define bfd_plugin_bfd_discard_group                  bfd_generic_discard_group
106#define bfd_plugin_section_already_linked             _bfd_generic_section_already_linked
107#define bfd_plugin_bfd_define_common_symbol           bfd_generic_define_common_symbol
108#define bfd_plugin_bfd_copy_link_hash_symbol_type     _bfd_generic_copy_link_hash_symbol_type
109#define bfd_plugin_bfd_link_check_relocs              _bfd_generic_link_check_relocs
110
111static enum ld_plugin_status
112message (int level ATTRIBUTE_UNUSED,
113	 const char * format, ...)
114{
115  va_list args;
116  va_start (args, format);
117  printf ("bfd plugin: ");
118  vprintf (format, args);
119  putchar ('\n');
120  va_end (args);
121  return LDPS_OK;
122}
123
124/* Register a claim-file handler. */
125static ld_plugin_claim_file_handler claim_file;
126
127static enum ld_plugin_status
128register_claim_file (ld_plugin_claim_file_handler handler)
129{
130  claim_file = handler;
131  return LDPS_OK;
132}
133
134static enum ld_plugin_status
135add_symbols (void * handle,
136	     int nsyms,
137	     const struct ld_plugin_symbol * syms)
138{
139  bfd *abfd = handle;
140  struct plugin_data_struct *plugin_data =
141    bfd_alloc (abfd, sizeof (plugin_data_struct));
142
143  plugin_data->nsyms = nsyms;
144  plugin_data->syms = syms;
145
146  if (nsyms != 0)
147    abfd->flags |= HAS_SYMS;
148
149  abfd->tdata.plugin_data = plugin_data;
150  return LDPS_OK;
151}
152
153static const char *plugin_program_name;
154
155void
156bfd_plugin_set_program_name (const char *program_name)
157{
158  plugin_program_name = program_name;
159}
160
161int
162bfd_plugin_open_input (bfd *ibfd, struct ld_plugin_input_file *file)
163{
164  bfd *iobfd;
165
166  iobfd = ibfd;
167  if (ibfd->my_archive && !bfd_is_thin_archive (ibfd->my_archive))
168    iobfd = ibfd->my_archive;
169  file->name = iobfd->filename;
170
171  if (!iobfd->iostream && !bfd_open_file (iobfd))
172    return 0;
173
174  file->fd = fileno ((FILE *) iobfd->iostream);
175
176  if (iobfd == ibfd)
177    {
178      struct stat stat_buf;
179      if (fstat (file->fd, &stat_buf))
180        return 0;
181      file->offset = 0;
182      file->filesize = stat_buf.st_size;
183    }
184  else
185    {
186      file->offset = ibfd->origin;
187      file->filesize = arelt_size (ibfd);
188    }
189  return 1;
190}
191
192static int
193try_claim (bfd *abfd)
194{
195  int claimed = 0;
196  struct ld_plugin_input_file file;
197
198  if (!bfd_plugin_open_input (abfd, &file))
199    return 0;
200  file.handle = abfd;
201  off_t cur_offset = lseek (file.fd, 0, SEEK_CUR);
202  claim_file (&file, &claimed);
203  lseek (file.fd, cur_offset, SEEK_SET);
204  return claimed;
205}
206
207static int
208try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p)
209{
210  void *plugin_handle;
211  struct ld_plugin_tv tv[4];
212  int i;
213  ld_plugin_onload onload;
214  enum ld_plugin_status status;
215
216  *has_plugin_p = 0;
217
218  plugin_handle = dlopen (pname, RTLD_NOW);
219  if (!plugin_handle)
220    {
221      _bfd_error_handler ("%s\n", dlerror ());
222      return 0;
223    }
224
225  onload = dlsym (plugin_handle, "onload");
226  if (!onload)
227    goto err;
228
229  i = 0;
230  tv[i].tv_tag = LDPT_MESSAGE;
231  tv[i].tv_u.tv_message = message;
232
233  ++i;
234  tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
235  tv[i].tv_u.tv_register_claim_file = register_claim_file;
236
237  ++i;
238  tv[i].tv_tag = LDPT_ADD_SYMBOLS;
239  tv[i].tv_u.tv_add_symbols = add_symbols;
240
241  ++i;
242  tv[i].tv_tag = LDPT_NULL;
243  tv[i].tv_u.tv_val = 0;
244
245  status = (*onload)(tv);
246
247  if (status != LDPS_OK)
248    goto err;
249
250  *has_plugin_p = 1;
251
252  abfd->plugin_format = bfd_plugin_no;
253
254  if (!claim_file)
255    goto err;
256
257  if (!try_claim (abfd))
258    goto err;
259
260  abfd->plugin_format = bfd_plugin_yes;
261
262  return 1;
263
264 err:
265  return 0;
266}
267
268/* There may be plugin libraries in lib/bfd-plugins.  */
269
270static int has_plugin = -1;
271
272static const bfd_target *(*ld_plugin_object_p) (bfd *);
273
274static const char *plugin_name;
275
276void
277bfd_plugin_set_plugin (const char *p)
278{
279  plugin_name = p;
280  has_plugin = p != NULL;
281}
282
283/* Return TRUE if a plugin library is used.  */
284
285bfd_boolean
286bfd_plugin_specified_p (void)
287{
288  return has_plugin > 0;
289}
290
291/* Return TRUE if ABFD can be claimed by linker LTO plugin.  */
292
293bfd_boolean
294bfd_link_plugin_object_p (bfd *abfd)
295{
296  if (ld_plugin_object_p)
297    return ld_plugin_object_p (abfd) != NULL;
298  return FALSE;
299}
300
301extern const bfd_target plugin_vec;
302
303/* Return TRUE if TARGET is a pointer to plugin_vec.  */
304
305bfd_boolean
306bfd_plugin_target_p (const bfd_target *target)
307{
308  return target == &plugin_vec;
309}
310
311/* Register OBJECT_P to be used by bfd_plugin_object_p.  */
312
313void
314register_ld_plugin_object_p (const bfd_target *(*object_p) (bfd *))
315{
316  ld_plugin_object_p = object_p;
317}
318
319static int
320load_plugin (bfd *abfd)
321{
322  char *plugin_dir;
323  char *p;
324  DIR *d;
325  struct dirent *ent;
326  int found = 0;
327
328  if (!has_plugin)
329    return found;
330
331  if (plugin_name)
332    return try_load_plugin (plugin_name, abfd, &has_plugin);
333
334  if (plugin_program_name == NULL)
335    return found;
336
337  plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
338  p = make_relative_prefix (plugin_program_name,
339			    BINDIR,
340			    plugin_dir);
341  free (plugin_dir);
342  plugin_dir = NULL;
343
344  d = opendir (p);
345  if (!d)
346    goto out;
347
348  while ((ent = readdir (d)))
349    {
350      char *full_name;
351      struct stat s;
352      int valid_plugin;
353
354      full_name = concat (p, "/", ent->d_name, NULL);
355      if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
356	found = try_load_plugin (full_name, abfd, &valid_plugin);
357      if (has_plugin <= 0)
358	has_plugin = valid_plugin;
359      free (full_name);
360      if (found)
361	break;
362    }
363
364 out:
365  free (p);
366  if (d)
367    closedir (d);
368
369  return found;
370}
371
372
373static const bfd_target *
374bfd_plugin_object_p (bfd *abfd)
375{
376  if (ld_plugin_object_p)
377    return ld_plugin_object_p (abfd);
378
379  if (abfd->plugin_format == bfd_plugin_unknown && !load_plugin (abfd))
380    return NULL;
381
382  return abfd->plugin_format == bfd_plugin_yes ? abfd->xvec : NULL;
383}
384
385/* Copy any private info we understand from the input bfd
386   to the output bfd.  */
387
388static bfd_boolean
389bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
390				      bfd *obfd ATTRIBUTE_UNUSED)
391{
392  BFD_ASSERT (0);
393  return TRUE;
394}
395
396/* Copy any private info we understand from the input section
397   to the output section.  */
398
399static bfd_boolean
400bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
401					  asection *isection ATTRIBUTE_UNUSED,
402					  bfd *obfd ATTRIBUTE_UNUSED,
403					  asection *osection ATTRIBUTE_UNUSED)
404{
405  BFD_ASSERT (0);
406  return TRUE;
407}
408
409/* Copy any private info we understand from the input symbol
410   to the output symbol.  */
411
412static bfd_boolean
413bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
414					 asymbol *isymbol ATTRIBUTE_UNUSED,
415					 bfd *obfd ATTRIBUTE_UNUSED,
416					 asymbol *osymbol ATTRIBUTE_UNUSED)
417{
418  BFD_ASSERT (0);
419  return TRUE;
420}
421
422static bfd_boolean
423bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
424{
425  BFD_ASSERT (0);
426  return TRUE;
427}
428
429static char *
430bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
431{
432  BFD_ASSERT (0);
433  return NULL;
434}
435
436static int
437bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
438{
439  BFD_ASSERT (0);
440  return 0;
441}
442
443static int
444bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
445{
446  BFD_ASSERT (0);
447  return 0;
448}
449
450static long
451bfd_plugin_get_symtab_upper_bound (bfd *abfd)
452{
453  struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
454  long nsyms = plugin_data->nsyms;
455
456  BFD_ASSERT (nsyms >= 0);
457
458  return ((nsyms + 1) * sizeof (asymbol *));
459}
460
461static flagword
462convert_flags (const struct ld_plugin_symbol *sym)
463{
464 switch (sym->def)
465   {
466   case LDPK_DEF:
467   case LDPK_COMMON:
468   case LDPK_UNDEF:
469     return BSF_GLOBAL;
470
471   case LDPK_WEAKUNDEF:
472   case LDPK_WEAKDEF:
473     return BSF_GLOBAL | BSF_WEAK;
474
475   default:
476     BFD_ASSERT (0);
477     return 0;
478   }
479}
480
481static long
482bfd_plugin_canonicalize_symtab (bfd *abfd,
483				asymbol **alocation)
484{
485  struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
486  long nsyms = plugin_data->nsyms;
487  const struct ld_plugin_symbol *syms = plugin_data->syms;
488  static asection fake_section;
489  static asection fake_common_section;
490  int i;
491
492  fake_section.name = ".text";
493  fake_common_section.flags = SEC_IS_COMMON;
494
495  for (i = 0; i < nsyms; i++)
496    {
497      asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
498
499      BFD_ASSERT (s);
500      alocation[i] = s;
501
502      s->the_bfd = abfd;
503      s->name = syms[i].name;
504      s->value = 0;
505      s->flags = convert_flags (&syms[i]);
506      switch (syms[i].def)
507	{
508	case LDPK_COMMON:
509	  s->section = &fake_common_section;
510	  break;
511	case LDPK_UNDEF:
512	case LDPK_WEAKUNDEF:
513	  s->section = bfd_und_section_ptr;
514	  break;
515	case LDPK_DEF:
516	case LDPK_WEAKDEF:
517	  s->section = &fake_section;
518	  break;
519	default:
520	  BFD_ASSERT (0);
521	}
522
523      s->udata.p = (void *) &syms[i];
524    }
525
526  return nsyms;
527}
528
529static void
530bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
531			 PTR afile ATTRIBUTE_UNUSED,
532			 asymbol *symbol ATTRIBUTE_UNUSED,
533			 bfd_print_symbol_type how ATTRIBUTE_UNUSED)
534{
535  BFD_ASSERT (0);
536}
537
538static void
539bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
540			    asymbol *symbol,
541			    symbol_info *ret)
542{
543  bfd_symbol_info (symbol, ret);
544}
545
546/* Make an empty symbol. */
547
548static asymbol *
549bfd_plugin_make_empty_symbol (bfd *abfd)
550{
551  asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
552  if (new_symbol == NULL)
553    return new_symbol;
554  new_symbol->the_bfd = abfd;
555  return new_symbol;
556}
557
558static int
559bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
560			   struct bfd_link_info *info ATTRIBUTE_UNUSED)
561{
562  BFD_ASSERT (0);
563  return 0;
564}
565
566const bfd_target plugin_vec =
567{
568  "plugin",			/* Name.  */
569  bfd_target_unknown_flavour,
570  BFD_ENDIAN_LITTLE,		/* Target byte order.  */
571  BFD_ENDIAN_LITTLE,		/* Target headers byte order.  */
572  (HAS_RELOC | EXEC_P |		/* Object flags.  */
573   HAS_LINENO | HAS_DEBUG |
574   HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
575  (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
576   | SEC_ALLOC | SEC_LOAD | SEC_RELOC),	/* Section flags.  */
577  0,				/* symbol_leading_char.  */
578  '/',				/* ar_pad_char.  */
579  15,				/* ar_max_namelen.  */
580  255,				/* match priority.  */
581
582  bfd_getl64, bfd_getl_signed_64, bfd_putl64,
583  bfd_getl32, bfd_getl_signed_32, bfd_putl32,
584  bfd_getl16, bfd_getl_signed_16, bfd_putl16,	/* data */
585  bfd_getl64, bfd_getl_signed_64, bfd_putl64,
586  bfd_getl32, bfd_getl_signed_32, bfd_putl32,
587  bfd_getl16, bfd_getl_signed_16, bfd_putl16,	/* hdrs */
588
589  {				/* bfd_check_format.  */
590    _bfd_dummy_target,
591    bfd_plugin_object_p,
592    bfd_generic_archive_p,
593    _bfd_dummy_target
594  },
595  {				/* bfd_set_format.  */
596    bfd_false,
597    bfd_false,
598    _bfd_generic_mkarchive,
599    bfd_false,
600  },
601  {				/* bfd_write_contents.  */
602    bfd_false,
603    bfd_false,
604    _bfd_write_archive_contents,
605    bfd_false,
606  },
607
608  BFD_JUMP_TABLE_GENERIC (bfd_plugin),
609  BFD_JUMP_TABLE_COPY (bfd_plugin),
610  BFD_JUMP_TABLE_CORE (bfd_plugin),
611#ifdef USE_64_BIT_ARCHIVE
612  BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
613#else
614  BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
615#endif
616  BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
617  BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
618  BFD_JUMP_TABLE_WRITE (bfd_plugin),
619  BFD_JUMP_TABLE_LINK (bfd_plugin),
620  BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
621
622  NULL,
623
624  NULL  			/* backend_data.  */
625};
626#endif /* BFD_SUPPORTS_PLUGIN */
627