path: root/src/util/os_installation.c

/*
     This file is part of GNUnet.
     Copyright (C) 2006-2018 GNUnet e.V.

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, or (at your
     option) any later version.

     GNUnet is 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 GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/

/**
 * @file src/util/os_installation.c
 * @brief get paths used by the program
 * @author Milan
 * @author Christian Fuchs
 * @author Christian Grothoff
 * @author Matthias Wachs
 * @author Heikki Lindholm
 * @author LRN
 */
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <unistr.h> /* for u16_to_u8 */

#include "platform.h"
#include "gnunet_util_lib.h"
#if DARWIN
#include <mach-o/ldsyms.h>
#include <mach-o/dyld.h>
#elif WINDOWS
#include <windows.h>
#endif


#define LOG(kind,...) GNUNET_log_from (kind, "util-os-installation", __VA_ARGS__)

#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util-os-installation", syscall, filename)


/**
 * Default project data used for installation path detection
 * for GNUnet (core).
 */
static const struct GNUNET_OS_ProjectData default_pd = {
  .libname = "libgnunetutil",
  .project_dirname = "gnunet",
  .binary_name = "gnunet-arm",
  .env_varname = "GNUNET_PREFIX",
  .base_config_varname = "GNUNET_BASE_CONFIG",
  .bug_email = "gnunet-developers@gnu.org",
  .homepage = "http://www.gnu.org/s/gnunet/",
  .config_file = "gnunet.conf",
  .user_config_file = "~/.config/gnunet.conf",
};

/**
 * Which project data do we currently use for installation
 * path detection? Never NULL.
 */
static const struct GNUNET_OS_ProjectData *current_pd = &default_pd;

/**
 * Return default project data used by 'libgnunetutil' for GNUnet.
 */
const struct GNUNET_OS_ProjectData *
GNUNET_OS_project_data_default (void)
{
  return &default_pd;
}


/**
 * @return current project data.
 */
const struct GNUNET_OS_ProjectData *
GNUNET_OS_project_data_get ()
{
  return current_pd;
}


/**
 * Setup OS subsystem with project data.
 *
 * @param pd project data used to determine paths
 */
void
GNUNET_OS_init (const struct GNUNET_OS_ProjectData *pd)
{
  GNUNET_assert (NULL != pd);
  current_pd = pd;
}


#if LINUX
/**
 * Try to determine path by reading /proc/PID/exe
 *
 * @return NULL on error
 */
static char *
get_path_from_proc_maps ()
{
  char fn[64];
  char line[1024];
  char dir[1024];
  FILE *f;
  char *lgu;

  GNUNET_snprintf (fn, sizeof (fn), "/proc/%u/maps", getpid ());
  if (NULL == (f = FOPEN (fn, "r")))
    return NULL;
  while (NULL != fgets (line, sizeof (line), f))
  {
    if ((1 ==
         SSCANF (line, "%*x-%*x %*c%*c%*c%*c %*x %*2x:%*2x %*u%*[ ]%1023s", dir)) &&
        (NULL != (lgu = strstr (dir,
                                current_pd->libname))))
    {
      lgu[0] = '\0';
      FCLOSE (f);
      return GNUNET_strdup (dir);
    }
  }
  FCLOSE (f);
  return NULL;
}


/**
 * Try to determine path by reading /proc/PID/exe
 *
 * @return NULL on error
 */
static char *
get_path_from_proc_exe ()
{
  char fn[64];
  char lnk[1024];
  ssize_t size;
  char *lep;

  GNUNET_snprintf (fn,
		   sizeof (fn),
		   "/proc/%u/exe",
		   getpid ());
  size = readlink (fn,
		   lnk,
		   sizeof (lnk) - 1);
  if (size <= 0)
  {
    LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR,
		       "readlink",
		       fn);
    return NULL;
  }
  GNUNET_assert ( ((size_t) size) < sizeof (lnk));
  lnk[size] = '\0';
  while ((lnk[size] != '/') && (size > 0))
    size--;
  GNUNET_asprintf (&lep,
                   "/%s/libexec/",
                   current_pd->project_dirname);
  /* test for being in lib/gnunet/libexec/ or lib/MULTIARCH/gnunet/libexec */
  if ( (((size_t) size) > strlen (lep)) &&
       (0 == strcmp (lep,
		     &lnk[size - strlen (lep)])) )
    size -= strlen (lep) - 1;
  GNUNET_free (lep);
  if ( (size < 4) ||
       (lnk[size - 4] != '/') )
  {
    /* not installed in "/bin/" -- binary path probably useless */
    return NULL;
  }
  lnk[size] = '\0';
  return GNUNET_strdup (lnk);
}
#endif


#if WINDOWS
static HINSTANCE dll_instance;


/**
 * GNUNET_util_cl_init() in common_logging.c is preferred.
 * This function is only for thread-local storage (not used in GNUnet)
 * and hInstance saving.
 */
BOOL WINAPI
DllMain (HINSTANCE hinstDLL,
         DWORD fdwReason,
         LPVOID lpvReserved)
{
  switch