2 * BinReloc - a library for creating relocatable executables
3 * Written by: Hongli Lai <h.lai@chello.nl>
4 * http://autopackage.org/
6 * This source code is public domain. You can relicense this code
7 * under whatever license you want.
9 * See http://autopackage.org/docs/binreloc/ for
10 * more information and how to use this.
13 #ifndef __BINRELOC_C__
14 #define __BINRELOC_C__
16 // [Christoph] use config.h, which defines ENABLE_BINRELOC
19 #ifdef ENABLE_BINRELOC
20 #include <sys/types.h>
23 #endif /* ENABLE_BINRELOC */
32 #endif /* __cplusplus */
37 * Find the canonical filename of the executable. Returns the filename
38 * (which must be freed) or NULL on error. If the parameter 'error' is
39 * not NULL, the error code will be stored there, if an error occured.
42 _br_find_exe (BrInitError *error)
44 #ifndef ENABLE_BINRELOC
46 *error = BR_INIT_ERROR_DISABLED;
49 char *path, *path2, *line, *result;
55 /* Read from /proc/self/exe (symlink) */
56 if (sizeof (path) > SSIZE_MAX)
57 buf_size = SSIZE_MAX - 1;
59 buf_size = PATH_MAX - 1;
60 path = (char *) malloc (buf_size);
62 /* Cannot allocate memory. */
64 *error = BR_INIT_ERROR_NOMEM;
67 path2 = (char *) malloc (buf_size);
69 /* Cannot allocate memory. */
71 *error = BR_INIT_ERROR_NOMEM;
76 strncpy (path2, "/proc/self/exe", buf_size - 1);
81 size = readlink (path2, path, buf_size - 1);
88 /* readlink() success. */
91 /* Check whether the symlink's target is also a symlink.
92 * We want to get the final target. */
93 i = stat (path, &stat_buf);
100 /* stat() success. */
101 if (!S_ISLNK (stat_buf.st_mode)) {
102 /* path is not a symlink. Done. */
107 /* path is a symlink. Continue loop and resolve this. */
108 strncpy (path, path2, buf_size - 1);
112 /* readlink() or stat() failed; this can happen when the program is
113 * running in Valgrind 2.2. Read from /proc/self/maps as fallback. */
115 buf_size = PATH_MAX + 128;
116 line = (char *) realloc (path, buf_size);
118 /* Cannot allocate memory. */
121 *error = BR_INIT_ERROR_NOMEM;
125 f = fopen ("/proc/self/maps", "r");
129 *error = BR_INIT_ERROR_OPEN_MAPS;
133 /* The first entry should be the executable name. */
134 result = fgets (line, (int) buf_size, f);
135 if (result == NULL) {
139 *error = BR_INIT_ERROR_READ_MAPS;
143 /* Get rid of newline character. */
144 buf_size = strlen (line);
146 /* Huh? An empty string? */
150 *error = BR_INIT_ERROR_INVALID_MAPS;
153 if (line[buf_size - 1] == 10)
154 line[buf_size - 1] = 0;
156 /* Extract the filename; it is always an absolute path. */
157 path = strchr (line, '/');
160 if (strstr (line, " r-xp ") == NULL || path == NULL) {
164 *error = BR_INIT_ERROR_INVALID_MAPS;
168 path = strdup (path);
172 #endif /* ENABLE_BINRELOC */
177 * Find the canonical filename of the executable which owns symbol.
178 * Returns a filename which must be freed, or NULL on error.
181 _br_find_exe_for_symbol (const void *symbol, BrInitError *error)
183 symbol = symbol; // [Christoph] mark it as used
184 #ifndef ENABLE_BINRELOC
186 *error = BR_INIT_ERROR_DISABLED;
187 return (char *) NULL;
189 #define SIZE PATH_MAX + 100
191 size_t address_string_len;
192 char *address_string, line[SIZE], *found;
195 return (char *) NULL;
197 f = fopen ("/proc/self/maps", "r");
199 return (char *) NULL;
201 address_string_len = 4;
202 address_string = (char *) malloc (address_string_len);
203 found = (char *) NULL;
206 char *start_addr, *end_addr, *end_addr_end, *file;
207 void *start_addr_p, *end_addr_p;
210 if (fgets (line, SIZE, f) == NULL)
214 if (strstr (line, " r-xp ") == NULL || strchr (line, '/') == NULL)
219 end_addr = strchr (line, '-');
220 file = strchr (line, '/');
222 /* More sanity check. */
223 if (!(file > end_addr && end_addr != NULL && end_addr[0] == '-'))
228 end_addr_end = strchr (end_addr, ' ');
229 if (end_addr_end == NULL)
232 end_addr_end[0] = '\0';
236 if (file[len - 1] == '\n')
237 file[len - 1] = '\0';
239 /* Get rid of "(deleted)" from the filename. */
241 if (len > 10 && strcmp (file + len - 10, " (deleted)") == 0)
242 file[len - 10] = '\0';
244 /* I don't know whether this can happen but better safe than sorry. */
245 len = strlen (start_addr);
246 if (len != strlen (end_addr))
250 /* Transform the addresses into a string in the form of 0xdeadbeef,
251 * then transform that into a pointer. */
252 if (address_string_len < len + 3) {
253 address_string_len = len + 3;
254 address_string = (char *) realloc (address_string, address_string_len);
257 memcpy (address_string, "0x", 2);
258 memcpy (address_string + 2, start_addr, len);
259 address_string[2 + len] = '\0';
260 sscanf (address_string, "%p", &start_addr_p);
262 memcpy (address_string, "0x", 2);
263 memcpy (address_string + 2, end_addr, len);
264 address_string[2 + len] = '\0';
265 sscanf (address_string, "%p", &end_addr_p);
268 if (symbol >= start_addr_p && symbol < end_addr_p) {
274 free (address_string);
278 return (char *) NULL;
280 return strdup (found);
281 #endif /* ENABLE_BINRELOC */
285 #ifndef BINRELOC_RUNNING_DOXYGEN
287 #define NULL ((void *) 0) /* typecasted as char* for C++ type safeness */
290 static char *exe = (char *) NULL;
293 /** Initialize the BinReloc library (for applications).
295 * This function must be called before using any other BinReloc functions.
296 * It attempts to locate the application's canonical filename.
298 * @note If you want to use BinReloc for a library, then you should call
299 * br_init_lib() instead.
301 * @param error If BinReloc failed to initialize, then the error code will
302 * be stored in this variable. Set to NULL if you want to
303 * ignore this. See #BrInitError for a list of error codes.
305 * @returns 1 on success, 0 if BinReloc failed to initialize.
308 br_init (BrInitError *error)
310 exe = _br_find_exe (error);
315 /** Initialize the BinReloc library (for libraries).
317 * This function must be called before using any other BinReloc functions.
318 * It attempts to locate the calling library's canonical filename.
320 * @note The BinReloc source code MUST be included in your library, or this
321 * function won't work correctly.
323 * @param error If BinReloc failed to initialize, then the error code will
324 * be stored in this variable. Set to NULL if you want to
325 * ignore this. See #BrInitError for a list of error codes.
327 * @returns 1 on success, 0 if a filename cannot be found.
330 br_init_lib (BrInitError *error)
332 exe = _br_find_exe_for_symbol ((const void *) "", error);
337 /** Find the canonical filename of the current application.
339 * @param default_exe A default filename which will be used as fallback.
340 * @returns A string containing the application's canonical filename,
341 * which must be freed when no longer necessary. If BinReloc is
342 * not initialized, or if br_init() failed, then a copy of
343 * default_exe will be returned. If default_exe is NULL, then
344 * NULL will be returned.
347 br_find_exe (const char *default_exe)
349 if (exe == (char *) NULL) {
350 /* BinReloc is not initialized. */
351 if (default_exe != (const char *) NULL)
352 return strdup (default_exe);
354 return (char *) NULL;
360 /** Locate the directory in which the current application is installed.
362 * The prefix is generated by the following pseudo-code evaluation:
367 * @param default_dir A default directory which will used as fallback.
368 * @return A string containing the directory, which must be freed when no
369 * longer necessary. If BinReloc is not initialized, or if the
370 * initialization function failed, then a copy of default_dir
371 * will be returned. If default_dir is NULL, then NULL will be
375 br_find_exe_dir (const char *default_dir)
378 /* BinReloc not initialized. */
379 if (default_dir != NULL)
380 return strdup (default_dir);
385 return br_dirname (exe);
389 /** Locate the prefix in which the current application is installed.
391 * The prefix is generated by the following pseudo-code evaluation:
393 * dirname(dirname(exename))
396 * @param default_prefix A default prefix which will used as fallback.
397 * @return A string containing the prefix, which must be freed when no
398 * longer necessary. If BinReloc is not initialized, or if
399 * the initialization function failed, then a copy of default_prefix
400 * will be returned. If default_prefix is NULL, then NULL will be returned.
403 br_find_prefix (const char *default_prefix)
407 if (exe == (char *) NULL) {
408 /* BinReloc not initialized. */
409 if (default_prefix != (const char *) NULL)
410 return strdup (default_prefix);
412 return (char *) NULL;
415 dir1 = br_dirname (exe);
416 dir2 = br_dirname (dir1);
422 /** Locate the application's binary folder.
424 * The path is generated by the following pseudo-code evaluation:
429 * @param default_bin_dir A default path which will used as fallback.
430 * @return A string containing the bin folder's path, which must be freed when
431 * no longer necessary. If BinReloc is not initialized, or if
432 * the initialization function failed, then a copy of default_bin_dir will
433 * be returned. If default_bin_dir is NULL, then NULL will be returned.
436 br_find_bin_dir (const char *default_bin_dir)
440 prefix = br_find_prefix ((const char *) NULL);
441 if (prefix == (char *) NULL) {
442 /* BinReloc not initialized. */
443 if (default_bin_dir != (const char *) NULL)
444 return strdup (default_bin_dir);
446 return (char *) NULL;
449 dir = br_build_path (prefix, "bin");
455 /** Locate the application's superuser binary folder.
457 * The path is generated by the following pseudo-code evaluation:
462 * @param default_sbin_dir A default path which will used as fallback.
463 * @return A string containing the sbin folder's path, which must be freed when
464 * no longer necessary. If BinReloc is not initialized, or if the
465 * initialization function failed, then a copy of default_sbin_dir will
466 * be returned. If default_bin_dir is NULL, then NULL will be returned.
469 br_find_sbin_dir (const char *default_sbin_dir)
473 prefix = br_find_prefix ((const char *) NULL);
474 if (prefix == (char *) NULL) {
475 /* BinReloc not initialized. */
476 if (default_sbin_dir != (const char *) NULL)
477 return strdup (default_sbin_dir);
479 return (char *) NULL;
482 dir = br_build_path (prefix, "sbin");
488 /** Locate the application's data folder.
490 * The path is generated by the following pseudo-code evaluation:
495 * @param default_data_dir A default path which will used as fallback.
496 * @return A string containing the data folder's path, which must be freed when
497 * no longer necessary. If BinReloc is not initialized, or if the
498 * initialization function failed, then a copy of default_data_dir
499 * will be returned. If default_data_dir is NULL, then NULL will be
503 br_find_data_dir (const char *default_data_dir)
507 prefix = br_find_prefix ((const char *) NULL);
508 if (prefix == (char *) NULL) {
509 /* BinReloc not initialized. */
510 if (default_data_dir != (const char *) NULL)
511 return strdup (default_data_dir);
513 return (char *) NULL;
516 dir = br_build_path (prefix, "share");
522 /** Locate the application's localization folder.
524 * The path is generated by the following pseudo-code evaluation:
526 * prefix + "/share/locale"
529 * @param default_locale_dir A default path which will used as fallback.
530 * @return A string containing the localization folder's path, which must be freed when
531 * no longer necessary. If BinReloc is not initialized, or if the
532 * initialization function failed, then a copy of default_locale_dir will be returned.
533 * If default_locale_dir is NULL, then NULL will be returned.
536 br_find_locale_dir (const char *default_locale_dir)
538 char *data_dir, *dir;
540 data_dir = br_find_data_dir ((const char *) NULL);
541 if (data_dir == (char *) NULL) {
542 /* BinReloc not initialized. */
543 if (default_locale_dir != (const char *) NULL)
544 return strdup (default_locale_dir);
546 return (char *) NULL;
549 dir = br_build_path (data_dir, "locale");
555 /** Locate the application's library folder.
557 * The path is generated by the following pseudo-code evaluation:
562 * @param default_lib_dir A default path which will used as fallback.
563 * @return A string containing the library folder's path, which must be freed when
564 * no longer necessary. If BinReloc is not initialized, or if the initialization
565 * function failed, then a copy of default_lib_dir will be returned.
566 * If default_lib_dir is NULL, then NULL will be returned.
569 br_find_lib_dir (const char *default_lib_dir)
573 prefix = br_find_prefix ((const char *) NULL);
574 if (prefix == (char *) NULL) {
575 /* BinReloc not initialized. */
576 if (default_lib_dir != (const char *) NULL)
577 return strdup (default_lib_dir);
579 return (char *) NULL;
582 dir = br_build_path (prefix, "lib");
588 /** Locate the application's libexec folder.
590 * The path is generated by the following pseudo-code evaluation:
592 * prefix + "/libexec"
595 * @param default_libexec_dir A default path which will used as fallback.
596 * @return A string containing the libexec folder's path, which must be freed when
597 * no longer necessary. If BinReloc is not initialized, or if the initialization
598 * function failed, then a copy of default_libexec_dir will be returned.
599 * If default_libexec_dir is NULL, then NULL will be returned.
602 br_find_libexec_dir (const char *default_libexec_dir)
606 prefix = br_find_prefix ((const char *) NULL);
607 if (prefix == (char *) NULL) {
608 /* BinReloc not initialized. */
609 if (default_libexec_dir != (const char *) NULL)
610 return strdup (default_libexec_dir);
612 return (char *) NULL;
615 dir = br_build_path (prefix, "libexec");
621 /** Locate the application's configuration files folder.
623 * The path is generated by the following pseudo-code evaluation:
628 * @param default_etc_dir A default path which will used as fallback.
629 * @return A string containing the etc folder's path, which must be freed when
630 * no longer necessary. If BinReloc is not initialized, or if the initialization
631 * function failed, then a copy of default_etc_dir will be returned.
632 * If default_etc_dir is NULL, then NULL will be returned.
635 br_find_etc_dir (const char *default_etc_dir)
639 prefix = br_find_prefix ((const char *) NULL);
640 if (prefix == (char *) NULL) {
641 /* BinReloc not initialized. */
642 if (default_etc_dir != (const char *) NULL)
643 return strdup (default_etc_dir);
645 return (char *) NULL;
648 dir = br_build_path (prefix, "etc");
654 /***********************
656 ***********************/
658 /** Concatenate str1 and str2 to a newly allocated string.
660 * @param str1 A string.
661 * @param str2 Another string.
662 * @returns A newly-allocated string. This string should be freed when no longer needed.
665 br_strcat (const char *str1, const char *str2)
675 len1 = strlen (str1);
676 len2 = strlen (str2);
678 result = (char *) malloc (len1 + len2 + 1);
679 memcpy (result, str1, len1);
680 memcpy (result + len1, str2, len2);
681 result[len1 + len2] = '\0';
688 br_build_path (const char *dir, const char *file)
695 if (len > 0 && dir[len - 1] != '/') {
696 dir2 = br_strcat (dir, "/");
701 result = br_strcat (dir2, file);
708 /* Emulates glibc's strndup() */
710 br_strndup (const char *str, size_t size)
712 char *result = (char *) NULL;
715 if (str == (const char *) NULL)
716 return (char *) NULL;
724 result = (char *) malloc (len + 1);
725 memcpy (result, str, size);
731 /** Extracts the directory component of a path.
733 * Similar to g_dirname() or the dirname commandline application.
737 * br_dirname ("/usr/local/foobar"); --> Returns: "/usr/local"
740 * @param path A path.
741 * @returns A directory name. This string should be freed when no longer needed.
744 br_dirname (const char *path)
748 if (path == (const char *) NULL)
749 return (char *) NULL;
751 end = strrchr (path, '/');
752 if (end == (const char *) NULL)
755 while (end > path && *end == '/')
757 result = br_strndup (path, end - path + 1);
758 if (result[0] == 0) {
768 #endif /* __cplusplus */
770 #endif /* __BINRELOC_C__ */