759 lines
19 KiB
C
759 lines
19 KiB
C
/*
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* BinReloc - a library for creating relocatable executables
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*
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* Originally written by: Hongli Lai <h.lai@chello.nl>
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* http://autopackage.org/ (defunct)
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*
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* Maintained by: Wolfgang 'datenwolf' Draxinger <coding@datenwolf.net>
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*
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* DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
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* Version 2, December 2004
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*
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* Everyone is permitted to copy and distribute verbatim or modified
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* copies of this license document, and changing it is allowed as long
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* as the name is changed.
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*
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* DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
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* TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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*
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* 0. You just DO WHAT THE FUCK YOU WANT TO.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <limits.h>
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#include <stdint.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <linux/limits.h>
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#include "binreloc.h"
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#ifndef SSIZE_MAX
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#define SSIZE_MAX ((ssize_t)(SIZE_MAX>>1))
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#endif
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/** @internal
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* Find the canonical filename of the executable. Returns the filename
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* (which must be freed) or NULL on error. If the parameter 'error' is
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* not NULL, the error code will be stored there, if an error occured.
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*/
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static char *
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_br_find_exe (BrInitError *error)
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{
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char *path, *path2, *line, *result;
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size_t buf_size;
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struct stat stat_buf;
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FILE *f;
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/* Read from /proc/self/exe (symlink) */
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if (sizeof (path) > SSIZE_MAX)
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buf_size = SSIZE_MAX - 1;
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else
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buf_size = PATH_MAX - 1;
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path = (char *) malloc (buf_size);
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if (path == NULL) {
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/* Cannot allocate memory. */
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if (error)
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*error = BR_INIT_ERROR_NOMEM;
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return NULL;
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}
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path2 = (char *) malloc (buf_size);
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if (path2 == NULL) {
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/* Cannot allocate memory. */
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if (error)
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*error = BR_INIT_ERROR_NOMEM;
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free (path);
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return NULL;
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}
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strncpy (path2, "/proc/self/exe", buf_size - 1);
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while (1) {
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int i;
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ssize_t size = readlink (path2, path, buf_size - 1);
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if (size == -1) {
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/* Error. */
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free (path2);
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break;
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}
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/* readlink() success. */
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path[size] = '\0';
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/* Check whether the symlink's target is also a symlink.
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* We want to get the final target. */
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i = stat (path, &stat_buf);
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if (i == -1) {
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/* Error. */
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free (path2);
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break;
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}
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/* stat() success. */
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if (!S_ISLNK (stat_buf.st_mode)) {
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/* path is not a symlink. Done. */
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free (path2);
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return path;
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}
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/* path is a symlink. Continue loop and resolve this. */
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strncpy (path, path2, buf_size - 1);
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}
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/* readlink() or stat() failed; this can happen when the program is
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* running in Valgrind 2.2. Read from /proc/self/maps as fallback. */
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buf_size = PATH_MAX + 128;
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line = (char *) realloc (path, buf_size);
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if (line == NULL) {
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/* Cannot allocate memory. */
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free (path);
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if (error)
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*error = BR_INIT_ERROR_NOMEM;
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return NULL;
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}
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f = fopen ("/proc/self/maps", "r");
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if (f == NULL) {
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free (line);
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if (error)
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*error = BR_INIT_ERROR_OPEN_MAPS;
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return NULL;
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}
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/* The first entry should be the executable name. */
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result = fgets (line, (int) buf_size, f);
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if (result == NULL) {
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fclose (f);
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free (line);
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if (error)
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*error = BR_INIT_ERROR_READ_MAPS;
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return NULL;
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}
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/* Get rid of newline character. */
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buf_size = strlen (line);
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if (buf_size == 0) {
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/* Huh? An empty string? */
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fclose (f);
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free (line);
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if (error)
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*error = BR_INIT_ERROR_INVALID_MAPS;
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return NULL;
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}
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if (line[buf_size - 1] == 10)
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line[buf_size - 1] = 0;
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/* Extract the filename; it is always an absolute path. */
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path = strchr (line, '/');
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/* Sanity check. */
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if (strstr (line, " r-xp ") == NULL || path == NULL) {
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fclose (f);
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free (line);
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if (error)
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*error = BR_INIT_ERROR_INVALID_MAPS;
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return NULL;
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}
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path = strdup (path);
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free (line);
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fclose (f);
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return path;
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}
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/** @internal
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* Find the canonical filename of the executable which owns symbol.
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* Returns a filename which must be freed, or NULL on error.
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*/
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static char *
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_br_find_exe_for_symbol (const void *symbol, BrInitError *error)
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{
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#define SIZE PATH_MAX + 100
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FILE *f;
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size_t address_string_len;
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char *address_string, line[SIZE], *found;
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if (symbol == NULL)
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return (char *) NULL;
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f = fopen ("/proc/self/maps", "r");
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if (f == NULL)
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return (char *) NULL;
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address_string_len = 4;
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address_string = (char *) malloc (address_string_len);
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found = (char *) NULL;
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while (!feof (f)) {
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char *start_addr, *end_addr, *end_addr_end, *file;
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void *start_addr_p, *end_addr_p;
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size_t len;
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if (fgets (line, SIZE, f) == NULL)
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break;
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/* Sanity check. */
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if (strstr (line, " r-xp ") == NULL || strchr (line, '/') == NULL)
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continue;
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/* Parse line. */
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start_addr = line;
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end_addr = strchr (line, '-');
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file = strchr (line, '/');
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/* More sanity check. */
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if (!(file > end_addr && end_addr != NULL && end_addr[0] == '-'))
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continue;
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end_addr[0] = '\0';
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end_addr++;
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end_addr_end = strchr (end_addr, ' ');
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if (end_addr_end == NULL)
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continue;
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end_addr_end[0] = '\0';
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len = strlen (file);
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if (len == 0)
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continue;
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if (file[len - 1] == '\n')
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file[len - 1] = '\0';
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/* Get rid of "(deleted)" from the filename. */
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len = strlen (file);
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if (len > 10 && strcmp (file + len - 10, " (deleted)") == 0)
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file[len - 10] = '\0';
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/* I don't know whether this can happen but better safe than sorry. */
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len = strlen (start_addr);
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if (len != strlen (end_addr))
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continue;
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/* Transform the addresses into a string in the form of 0xdeadbeef,
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* then transform that into a pointer. */
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if (address_string_len < len + 3) {
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address_string_len = len + 3;
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char *new_address_string = (char *) realloc (address_string, address_string_len);
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if (new_address_string == NULL){
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*error = BR_INIT_ERROR_NOMEM;
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free (address_string);
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fclose (f);
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return (char *) NULL;
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}
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else
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address_string = new_address_string;
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}
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memcpy (address_string, "0x", 2);
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memcpy (address_string + 2, start_addr, len);
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address_string[2 + len] = '\0';
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sscanf (address_string, "%p", &start_addr_p);
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memcpy (address_string, "0x", 2);
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memcpy (address_string + 2, end_addr, len);
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address_string[2 + len] = '\0';
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sscanf (address_string, "%p", &end_addr_p);
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if (symbol >= start_addr_p && symbol < end_addr_p) {
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found = file;
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break;
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}
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}
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free (address_string);
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fclose (f);
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if (found == NULL)
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return (char *) NULL;
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else
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return strdup (found);
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}
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#ifndef BINRELOC_RUNNING_DOXYGEN
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#undef NULL
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#define NULL ((void *) 0) /* typecasted as char* for C++ type safeness */
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#endif
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static char *exe = (char *) NULL;
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/** Initialize the BinReloc library (for applications).
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*
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* This function must be called before using any other BinReloc functions.
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* It attempts to locate the application's canonical filename.
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*
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* @note If you want to use BinReloc for a library, then you should call
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* br_init_lib() instead.
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*
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* @param error If BinReloc failed to initialize, then the error code will
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* be stored in this variable. Set to NULL if you want to
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* ignore this. See #BrInitError for a list of error codes.
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*
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* @returns 1 on success, 0 if BinReloc failed to initialize.
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*/
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int
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br_init (BrInitError *error)
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{
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exe = _br_find_exe (error);
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return exe != NULL;
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}
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/** Initialize the BinReloc library (for libraries).
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*
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* This function must be called before using any other BinReloc functions.
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* It attempts to locate the calling library's canonical filename.
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*
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* @note The BinReloc source code MUST be included in your library, or this
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* function won't work correctly.
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*
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* @param error If BinReloc failed to initialize, then the error code will
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* be stored in this variable. Set to NULL if you want to
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* ignore this. See #BrInitError for a list of error codes.
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*
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* @returns 1 on success, 0 if a filename cannot be found.
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*/
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int
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br_init_lib (BrInitError *error)
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{
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exe = _br_find_exe_for_symbol ((const void *) "", error);
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return exe != NULL;
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}
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/** Find the canonical filename of the current application.
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*
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* @param default_exe A default filename which will be used as fallback.
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* @returns A string containing the application's canonical filename,
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* which must be freed when no longer necessary. If BinReloc is
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* not initialized, or if br_init() failed, then a copy of
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* default_exe will be returned. If default_exe is NULL, then
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* NULL will be returned.
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*/
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char *
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br_find_exe (const char *default_exe)
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{
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if (exe == (char *) NULL) {
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/* BinReloc is not initialized. */
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if (default_exe != (const char *) NULL)
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return strdup (default_exe);
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else
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return (char *) NULL;
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}
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return strdup (exe);
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}
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/** Locate the directory in which the current application is installed.
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*
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* The prefix is generated by the following pseudo-code evaluation:
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* \code
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* dirname(exename)
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* \endcode
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*
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* @param default_dir A default directory which will used as fallback.
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* @return A string containing the directory, which must be freed when no
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* longer necessary. If BinReloc is not initialized, or if the
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* initialization function failed, then a copy of default_dir
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* will be returned. If default_dir is NULL, then NULL will be
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* returned.
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*/
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char *
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br_find_exe_dir (const char *default_dir)
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{
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if (exe == NULL) {
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/* BinReloc not initialized. */
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if (default_dir != NULL)
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return strdup (default_dir);
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else
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return NULL;
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}
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return br_dirname (exe);
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}
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/** Locate the prefix in which the current application is installed.
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*
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* The prefix is generated by the following pseudo-code evaluation:
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* \code
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* dirname(dirname(exename))
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* \endcode
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*
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* @param default_prefix A default prefix which will used as fallback.
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* @return A string containing the prefix, which must be freed when no
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* longer necessary. If BinReloc is not initialized, or if
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* the initialization function failed, then a copy of default_prefix
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* will be returned. If default_prefix is NULL, then NULL will be returned.
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*/
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char *
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br_find_prefix (const char *default_prefix)
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{
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char *dir1, *dir2;
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if (exe == (char *) NULL) {
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/* BinReloc not initialized. */
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if (default_prefix != (const char *) NULL)
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return strdup (default_prefix);
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else
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return (char *) NULL;
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}
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dir1 = br_dirname (exe);
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dir2 = br_dirname (dir1);
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free (dir1);
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return dir2;
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}
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/** Locate the application's binary folder.
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*
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* The path is generated by the following pseudo-code evaluation:
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* \code
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* prefix + "/bin"
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* \endcode
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*
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* @param default_bin_dir A default path which will used as fallback.
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* @return A string containing the bin folder's path, which must be freed when
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* no longer necessary. If BinReloc is not initialized, or if
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* the initialization function failed, then a copy of default_bin_dir will
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* be returned. If default_bin_dir is NULL, then NULL will be returned.
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*/
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char *
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br_find_bin_dir (const char *default_bin_dir)
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{
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char *prefix, *dir;
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prefix = br_find_prefix ((const char *) NULL);
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if (prefix == (char *) NULL) {
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/* BinReloc not initialized. */
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if (default_bin_dir != (const char *) NULL)
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return strdup (default_bin_dir);
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else
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return (char *) NULL;
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}
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dir = br_build_path (prefix, "bin");
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free (prefix);
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return dir;
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}
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/** Locate the application's superuser binary folder.
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*
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* The path is generated by the following pseudo-code evaluation:
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* \code
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* prefix + "/sbin"
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* \endcode
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*
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* @param default_sbin_dir A default path which will used as fallback.
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* @return A string containing the sbin folder's path, which must be freed when
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* no longer necessary. If BinReloc is not initialized, or if the
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* initialization function failed, then a copy of default_sbin_dir will
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* be returned. If default_bin_dir is NULL, then NULL will be returned.
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*/
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char *
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br_find_sbin_dir (const char *default_sbin_dir)
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{
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char *prefix, *dir;
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prefix = br_find_prefix ((const char *) NULL);
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if (prefix == (char *) NULL) {
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/* BinReloc not initialized. */
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if (default_sbin_dir != (const char *) NULL)
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return strdup (default_sbin_dir);
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else
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return (char *) NULL;
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}
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dir = br_build_path (prefix, "sbin");
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free (prefix);
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return dir;
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}
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/** Locate the application's data folder.
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*
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* The path is generated by the following pseudo-code evaluation:
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* \code
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* prefix + "/share"
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* \endcode
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*
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* @param default_data_dir A default path which will used as fallback.
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* @return A string containing the data folder's path, which must be freed when
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* no longer necessary. If BinReloc is not initialized, or if the
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* initialization function failed, then a copy of default_data_dir
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* will be returned. If default_data_dir is NULL, then NULL will be
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* returned.
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*/
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char *
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br_find_data_dir (const char *default_data_dir)
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{
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char *prefix, *dir;
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prefix = br_find_prefix ((const char *) NULL);
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if (prefix == (char *) NULL) {
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/* BinReloc not initialized. */
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if (default_data_dir != (const char *) NULL)
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return strdup (default_data_dir);
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else
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return (char *) NULL;
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}
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dir = br_build_path (prefix, "share");
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free (prefix);
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return dir;
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}
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/** Locate the application's localization folder.
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*
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* The path is generated by the following pseudo-code evaluation:
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* \code
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* prefix + "/share/locale"
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* \endcode
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*
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* @param default_locale_dir A default path which will used as fallback.
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* @return A string containing the localization folder's path, which must be freed when
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* no longer necessary. If BinReloc is not initialized, or if the
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* initialization function failed, then a copy of default_locale_dir will be returned.
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* If default_locale_dir is NULL, then NULL will be returned.
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*/
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char *
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br_find_locale_dir (const char *default_locale_dir)
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{
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char *data_dir, *dir;
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data_dir = br_find_data_dir ((const char *) NULL);
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if (data_dir == (char *) NULL) {
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/* BinReloc not initialized. */
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if (default_locale_dir != (const char *) NULL)
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return strdup (default_locale_dir);
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else
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return (char *) NULL;
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}
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dir = br_build_path (data_dir, "locale");
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free (data_dir);
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return dir;
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}
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/** Locate the application's library folder.
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*
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* The path is generated by the following pseudo-code evaluation:
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* \code
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* prefix + "/lib"
|
|
* \endcode
|
|
*
|
|
* @param default_lib_dir A default path which will used as fallback.
|
|
* @return A string containing the library folder's path, which must be freed when
|
|
* no longer necessary. If BinReloc is not initialized, or if the initialization
|
|
* function failed, then a copy of default_lib_dir will be returned.
|
|
* If default_lib_dir is NULL, then NULL will be returned.
|
|
*/
|
|
char *
|
|
br_find_lib_dir (const char *default_lib_dir)
|
|
{
|
|
char *prefix, *dir;
|
|
|
|
prefix = br_find_prefix ((const char *) NULL);
|
|
if (prefix == (char *) NULL) {
|
|
/* BinReloc not initialized. */
|
|
if (default_lib_dir != (const char *) NULL)
|
|
return strdup (default_lib_dir);
|
|
else
|
|
return (char *) NULL;
|
|
}
|
|
|
|
dir = br_build_path (prefix, "lib");
|
|
free (prefix);
|
|
return dir;
|
|
}
|
|
|
|
|
|
/** Locate the application's libexec folder.
|
|
*
|
|
* The path is generated by the following pseudo-code evaluation:
|
|
* \code
|
|
* prefix + "/libexec"
|
|
* \endcode
|
|
*
|
|
* @param default_libexec_dir A default path which will used as fallback.
|
|
* @return A string containing the libexec folder's path, which must be freed when
|
|
* no longer necessary. If BinReloc is not initialized, or if the initialization
|
|
* function failed, then a copy of default_libexec_dir will be returned.
|
|
* If default_libexec_dir is NULL, then NULL will be returned.
|
|
*/
|
|
char *
|
|
br_find_libexec_dir (const char *default_libexec_dir)
|
|
{
|
|
char *prefix, *dir;
|
|
|
|
prefix = br_find_prefix ((const char *) NULL);
|
|
if (prefix == (char *) NULL) {
|
|
/* BinReloc not initialized. */
|
|
if (default_libexec_dir != (const char *) NULL)
|
|
return strdup (default_libexec_dir);
|
|
else
|
|
return (char *) NULL;
|
|
}
|
|
|
|
dir = br_build_path (prefix, "libexec");
|
|
free (prefix);
|
|
return dir;
|
|
}
|
|
|
|
|
|
/** Locate the application's configuration files folder.
|
|
*
|
|
* The path is generated by the following pseudo-code evaluation:
|
|
* \code
|
|
* prefix + "/etc"
|
|
* \endcode
|
|
*
|
|
* @param default_etc_dir A default path which will used as fallback.
|
|
* @return A string containing the etc folder's path, which must be freed when
|
|
* no longer necessary. If BinReloc is not initialized, or if the initialization
|
|
* function failed, then a copy of default_etc_dir will be returned.
|
|
* If default_etc_dir is NULL, then NULL will be returned.
|
|
*/
|
|
char *
|
|
br_find_etc_dir (const char *default_etc_dir)
|
|
{
|
|
char *prefix, *dir;
|
|
|
|
prefix = br_find_prefix ((const char *) NULL);
|
|
if (prefix == (char *) NULL) {
|
|
/* BinReloc not initialized. */
|
|
if (default_etc_dir != (const char *) NULL)
|
|
return strdup (default_etc_dir);
|
|
else
|
|
return (char *) NULL;
|
|
}
|
|
|
|
dir = br_build_path (prefix, "etc");
|
|
free (prefix);
|
|
return dir;
|
|
}
|
|
|
|
|
|
/***********************
|
|
* Utility functions
|
|
***********************/
|
|
|
|
/** Concatenate str1 and str2 to a newly allocated string.
|
|
*
|
|
* @param str1 A string.
|
|
* @param str2 Another string.
|
|
* @returns A newly-allocated string. This string should be freed when no longer needed.
|
|
*/
|
|
char *
|
|
br_strcat (const char *str1, const char *str2)
|
|
{
|
|
char *result;
|
|
size_t len1, len2;
|
|
|
|
if (str1 == NULL)
|
|
str1 = "";
|
|
if (str2 == NULL)
|
|
str2 = "";
|
|
|
|
len1 = strlen (str1);
|
|
len2 = strlen (str2);
|
|
|
|
result = (char *) malloc (len1 + len2 + 1);
|
|
memcpy (result, str1, len1);
|
|
memcpy (result + len1, str2, len2);
|
|
result[len1 + len2] = '\0';
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
char *
|
|
br_build_path (const char *dir, const char *file)
|
|
{
|
|
char *result;
|
|
size_t len;
|
|
|
|
len = strlen (dir);
|
|
if (len > 0 && dir[len - 1] != '/') {
|
|
char *dir2 = br_strcat (dir, "/");
|
|
result = br_strcat (dir2, file);
|
|
free (dir2);
|
|
} else
|
|
result = br_strcat (dir, file);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
/* Emulates glibc's strndup() */
|
|
static char *
|
|
br_strndup (const char *str, size_t size)
|
|
{
|
|
char *result = (char *) NULL;
|
|
size_t len;
|
|
|
|
if (str == (const char *) NULL)
|
|
return (char *) NULL;
|
|
|
|
len = strlen (str);
|
|
if (len == 0)
|
|
return strdup ("");
|
|
if (size > len)
|
|
size = len;
|
|
|
|
result = (char *) malloc (len + 1);
|
|
memcpy (result, str, size);
|
|
result[size] = '\0';
|
|
return result;
|
|
}
|
|
|
|
|
|
/** Extracts the directory component of a path.
|
|
*
|
|
* Similar to g_dirname() or the dirname commandline application.
|
|
*
|
|
* Example:
|
|
* \code
|
|
* br_dirname ("/usr/local/foobar"); --> Returns: "/usr/local"
|
|
* \endcode
|
|
*
|
|
* @param path A path.
|
|
* @returns A directory name. This string should be freed when no longer needed.
|
|
*/
|
|
char *
|
|
br_dirname (const char *path)
|
|
{
|
|
char *end, *result;
|
|
|
|
if (path == (const char *) NULL)
|
|
return (char *) NULL;
|
|
|
|
end = strrchr (path, '/');
|
|
if (end == (const char *) NULL)
|
|
return strdup (".");
|
|
|
|
while (end > path && *end == '/')
|
|
end--;
|
|
result = br_strndup (path, (size_t)(end - path + 1));
|
|
if (result[0] == 0) {
|
|
free (result);
|
|
return strdup ("/");
|
|
} else
|
|
return result;
|
|
}
|
|
|