binreloc.c

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// $Id: binreloc.c 757 2006-04-01 16:04:45Z alex $
// The following line makes normalize.pl skip type fixing
/* SKIPFIXTYPES: START */
// $Id: appstate.cpp 836 2006-04-18 16:06:15Z gerry $
/* @@tag:xara-cn@@ DO NOT MODIFY THIS LINE
================================XARAHEADERSTART===========================
 
               Xara LX, a vector drawing and manipulation program.
                    Copyright (C) 1993-2006 Xara Group Ltd.
       Copyright on certain contributions may be held in joint with their
              respective authors. See AUTHORS file for details.

LICENSE TO USE AND MODIFY SOFTWARE
----------------------------------

This file is part of Xara LX.

Xara LX is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License version 2 as published
by the Free Software Foundation.

Xara LX and its component source files are distributed in the hope
that it will be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with Xara LX (see the file GPL in the root directory of the
distribution); if not, write to the Free Software Foundation, Inc., 51
Franklin St, Fifth Floor, Boston, MA  02110-1301 USA


ADDITIONAL RIGHTS
-----------------

Conditional upon your continuing compliance with the GNU General Public
License described above, Xara Group Ltd grants to you certain additional
rights. 

The additional rights are to use, modify, and distribute the software
together with the wxWidgets library, the wxXtra library, and the "CDraw"
library and any other such library that any version of Xara LX relased
by Xara Group Ltd requires in order to compile and execute, including
the static linking of that library to XaraLX. In the case of the
"CDraw" library, you may satisfy obligation under the GNU General Public
License to provide source code by providing a binary copy of the library
concerned and a copy of the license accompanying it.

Nothing in this section restricts any of the rights you have under
the GNU General Public License.


SCOPE OF LICENSE
----------------

This license applies to this program (XaraLX) and its constituent source
files only, and does not necessarily apply to other Xara products which may
in part share the same code base, and are subject to their own licensing
terms.

This license does not apply to files in the wxXtra directory, which
are built into a separate library, and are subject to the wxWindows
license contained within that directory in the file "WXXTRA-LICENSE".

This license does not apply to the binary libraries (if any) within
the "libs" directory, which are subject to a separate license contained
within that directory in the file "LIBS-LICENSE".


ARRANGEMENTS FOR CONTRIBUTION OF MODIFICATIONS
----------------------------------------------

Subject to the terms of the GNU Public License (see above), you are
free to do whatever you like with your modifications. However, you may
(at your option) wish contribute them to Xara's source tree. You can
find details of how to do this at:
  http://www.xaraxtreme.org/developers/

Prior to contributing your modifications, you will need to complete our
contributor agreement. This can be found at:
  http://www.xaraxtreme.org/developers/contribute/

Please note that Xara will not accept modifications which modify any of
the text between the start and end of this header (marked
XARAHEADERSTART and XARAHEADEREND).


MARKS
-----

Xara, Xara LX, Xara X, Xara X/Xtreme, Xara Xtreme, the Xtreme and Xara
designs are registered or unregistered trademarks, design-marks, and/or
service marks of Xara Group Ltd. All rights in these marks are reserved.


      Xara Group Ltd, Gaddesden Place, Hemel Hempstead, HP2 6EX, UK.
                        http://www.xara.com/

=================================XARAHEADEREND============================
*/
/*
 * BinReloc - a library for creating relocatable executables
 * Written by: Hongli Lai <h.lai@chello.nl>
 * http://autopackage.org/
 *
 * This source code is public domain. You can relicense this code
 * under whatever license you want.
 *
 * See http://autopackage.org/docs/binreloc/ for
 * more information and how to use this.
 */

#ifndef __BINRELOC_C__
#define __BINRELOC_C__

#ifdef ENABLE_BINRELOC
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <unistd.h>
#endif /* ENABLE_BINRELOC */
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include "binreloc.h"

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */



static char *
_br_find_exe (BrInitError *error)
{
#ifndef ENABLE_BINRELOC
    if (error)
        *error = BR_INIT_ERROR_DISABLED;
    return NULL;
#else
    char *path, *path2, *line, *result;
    size_t buf_size;
    ssize_t size;
    struct stat stat_buf;
    FILE *f;

    /* Read from /proc/self/exe (symlink) */
    if (sizeof (path) > SSIZE_MAX)
        buf_size = SSIZE_MAX - 1;
    else
        buf_size = PATH_MAX - 1;
    path = (char *) malloc (buf_size);
    if (path == NULL) {
        /* Cannot allocate memory. */
        if (error)
            *error = BR_INIT_ERROR_NOMEM;
        return NULL;
    }
    path2 = (char *) malloc (buf_size);
    if (path2 == NULL) {
        /* Cannot allocate memory. */
        if (error)
            *error = BR_INIT_ERROR_NOMEM;
        free (path);
        return NULL;
    }

    strncpy (path2, "/proc/self/exe", buf_size - 1);

    while (1) {
        int i;

        size = readlink (path2, path, buf_size - 1);
        if (size == -1) {
            /* Error. */
            free (path2);
            break;
        }

        /* readlink() success. */
        path[size] = '\0';

        /* Check whether the symlink's target is also a symlink.
         * We want to get the final target. */
        i = stat (path, &stat_buf);
        if (i == -1) {
            /* Error. */
            free (path2);
            break;
        }

        /* stat() success. */
        if (!S_ISLNK (stat_buf.st_mode)) {
            /* path is not a symlink. Done. */
            free (path2);
            return path;
        }

        /* path is a symlink. Continue loop and resolve this. */
        strncpy (path, path2, buf_size - 1);
    }


    /* readlink() or stat() failed; this can happen when the program is
     * running in Valgrind 2.2. Read from /proc/self/maps as fallback. */

    buf_size = PATH_MAX + 128;
    line = (char *) realloc (path, buf_size);
    if (line == NULL) {
        /* Cannot allocate memory. */
        free (path);
        if (error)
            *error = BR_INIT_ERROR_NOMEM;
        return NULL;
    }

    f = fopen ("/proc/self/maps", "r");
    if (f == NULL) {
        free (line);
        if (error)
            *error = BR_INIT_ERROR_OPEN_MAPS;
        return NULL;
    }

    /* The first entry should be the executable name. */
    result = fgets (line, (int) buf_size, f);
    if (result == NULL) {
        fclose (f);
        free (line);
        if (error)
            *error = BR_INIT_ERROR_READ_MAPS;
        return NULL;
    }

    /* Get rid of newline character. */
    buf_size = strlen (line);
    if (buf_size <= 0) {
        /* Huh? An empty string? */
        fclose (f);
        free (line);
        if (error)
            *error = BR_INIT_ERROR_INVALID_MAPS;
        return NULL;
    }
    if (line[buf_size - 1] == 10)
        line[buf_size - 1] = 0;

    /* Extract the filename; it is always an absolute path. */
    path = strchr (line, '/');

    /* Sanity check. */
    if (strstr (line, " r-xp ") == NULL || path == NULL) {
        fclose (f);
        free (line);
        if (error)
            *error = BR_INIT_ERROR_INVALID_MAPS;
        return NULL;
    }

    path = strdup (path);
    free (line);
    fclose (f);
    return path;
#endif /* ENABLE_BINRELOC */
}


static char *
_br_find_exe_for_symbol (const void *symbol, BrInitError *error)
{
#ifndef ENABLE_BINRELOC
    if (error)
        *error = BR_INIT_ERROR_DISABLED;
    return (char *) NULL;
#else
    #define SIZE PATH_MAX + 100
    FILE *f;
    size_t address_string_len;
    char *address_string, line[SIZE], *found;

    if (symbol == NULL)
        return (char *) NULL;

    f = fopen ("/proc/self/maps", "r");
    if (f == NULL)
        return (char *) NULL;

    address_string_len = 4;
    address_string = (char *) malloc (address_string_len);
    found = (char *) NULL;

    while (!feof (f)) {
        char *start_addr, *end_addr, *end_addr_end, *file;
        void *start_addr_p, *end_addr_p;
        size_t len;

        if (fgets (line, SIZE, f) == NULL)
            break;

        /* Sanity check. */
        if (strstr (line, " r-xp ") == NULL || strchr (line, '/') == NULL)
            continue;

        /* Parse line. */
        start_addr = line;
        end_addr = strchr (line, '-');
        file = strchr (line, '/');

        /* More sanity check. */
        if (!(file > end_addr && end_addr != NULL && end_addr[0] == '-'))
            continue;

        end_addr[0] = '\0';
        end_addr++;
        end_addr_end = strchr (end_addr, ' ');
        if (end_addr_end == NULL)
            continue;

        end_addr_end[0] = '\0';
        len = strlen (file);
        if (len == 0)
            continue;
        if (file[len - 1] == '\n')
            file[len - 1] = '\0';

        /* Get rid of "(deleted)" from the filename. */
        len = strlen (file);
        if (len > 10 && strcmp (file + len - 10, " (deleted)") == 0)
            file[len - 10] = '\0';

        /* I don't know whether this can happen but better safe than sorry. */
        len = strlen (start_addr);
        if (len != strlen (end_addr))
            continue;


        /* Transform the addresses into a string in the form of 0xdeadbeef,
         * then transform that into a pointer. */
        if (address_string_len < len + 3) {
            address_string_len = len + 3;
            address_string = (char *) realloc (address_string, address_string_len);
        }

        memcpy (address_string, "0x", 2);
        memcpy (address_string + 2, start_addr, len);
        address_string[2 + len] = '\0';
        sscanf (address_string, "%p", &start_addr_p);

        memcpy (address_string, "0x", 2);
        memcpy (address_string + 2, end_addr, len);
        address_string[2 + len] = '\0';
        sscanf (address_string, "%p", &end_addr_p);


        if (symbol >= start_addr_p && symbol < end_addr_p) {
            found = file;
            break;
        }
    }

    free (address_string);
    fclose (f);

    if (found == NULL)
        return (char *) NULL;
    else
        return strdup (found);
#endif /* ENABLE_BINRELOC */
}


#ifndef BINRELOC_RUNNING_DOXYGEN
    #undef NULL
    #define NULL ((void *) 0) /* typecasted as char* for C++ type safeness */
#endif

static char *exe = (char *) NULL;


int
br_init (BrInitError *error)
{
    exe = _br_find_exe (error);
    return exe != NULL;
}


int
br_init_lib (BrInitError *error)
{
    exe = _br_find_exe_for_symbol ((const void *) "", error);
    return exe != NULL;
}


char *
br_find_exe (const char *default_exe)
{
    if (exe == (char *) NULL) {
        /* BinReloc is not initialized. */
        if (default_exe != (const char *) NULL)
            return strdup (default_exe);
        else
            return (char *) NULL;
    }
    return strdup (exe);
}


char *
br_find_exe_dir (const char *default_dir)
{
    if (exe == NULL) {
        /* BinReloc not initialized. */
        if (default_dir != NULL)
            return strdup (default_dir);
        else
            return NULL;
    }

    return br_dirname (exe);
}


char *
br_find_prefix (const char *default_prefix)
{
    char *dir1, *dir2;

    if (exe == (char *) NULL) {
        /* BinReloc not initialized. */
        if (default_prefix != (const char *) NULL)
            return strdup (default_prefix);
        else
            return (char *) NULL;
    }

    dir1 = br_dirname (exe);
    dir2 = br_dirname (dir1);
    free (dir1);
    return dir2;
}


char *
br_find_bin_dir (const char *default_bin_dir)
{
    char *prefix, *dir;

    prefix = br_find_prefix ((const char *) NULL);
    if (prefix == (char *) NULL) {
        /* BinReloc not initialized. */
        if (default_bin_dir != (const char *) NULL)
            return strdup (default_bin_dir);
        else
            return (char *) NULL;
    }

    dir = br_build_path (prefix, "bin");
    free (prefix);
    return dir;
}


char *
br_find_sbin_dir (const char *default_sbin_dir)
{
    char *prefix, *dir;

    prefix = br_find_prefix ((const char *) NULL);
    if (prefix == (char *) NULL) {
        /* BinReloc not initialized. */
        if (default_sbin_dir != (const char *) NULL)
            return strdup (default_sbin_dir);
        else
            return (char *) NULL;
    }

    dir = br_build_path (prefix, "sbin");
    free (prefix);
    return dir;
}


char *
br_find_data_dir (const char *default_data_dir)
{
    char *prefix, *dir;

    prefix = br_find_prefix ((const char *) NULL);
    if (prefix == (char *) NULL) {
        /* BinReloc not initialized. */
        if (default_data_dir != (const char *) NULL)
            return strdup (default_data_dir);
        else
            return (char *) NULL;
    }

    dir = br_build_path (prefix, "share");
    free (prefix);
    return dir;
}


char *
br_find_locale_dir (const char *default_locale_dir)
{
    char *data_dir, *dir;

    data_dir = br_find_data_dir ((const char *) NULL);
    if (data_dir == (char *) NULL) {
        /* BinReloc not initialized. */
        if (default_locale_dir != (const char *) NULL)
            return strdup (default_locale_dir);
        else
            return (char *) NULL;
    }

    dir = br_build_path (data_dir, "locale");
    free (data_dir);
    return dir;
}


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;
}


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;
}


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
 ***********************/

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 *dir2, *result;
    size_t len;
    int must_free = 0;

    len = strlen (dir);
    if (len > 0 && dir[len - 1] != '/') {
        dir2 = br_strcat (dir, "/");
        must_free = 1;
    } else
        dir2 = (char *) dir;

    result = br_strcat (dir2, file);
    if (must_free)
        free (dir2);
    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;
}


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, end - path + 1);
    if (result[0] == 0) {
        free (result);
        return strdup ("/");
    } else
        return result;
}


#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* __BINRELOC_C__ */

---