Geografic-Information-System/lib/gis/mapset_msc.c

/*!
   \file lib/gis/mapset_msc.c

   \brief GIS library - Mapset user permission routines.

   (C) 1999-2014 The GRASS development team

   This program is free software under the GNU General Public License
   (>=v2). Read the file COPYING that comes with GRASS for details.
 */

#include <grass/config.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <grass/gis.h>
#include <grass/glocale.h>

static int make_mapset_element(const char *, const char *);

/*!
   \brief Create element in the current mapset.

   Make the specified element in the current mapset will check for the
   existence of the element and do nothing if it is found so this
   routine can be called even if the element already exists.
   
   Calls G_fatal_error() on failure.
   
   \param p_element element to be created in mapset

   \return 0 no element defined
   \return 1 on success
 */
int G_make_mapset_element(const char *p_element)
{
    char path[GPATH_MAX];
    
    G_file_name(path, NULL, NULL, G_mapset());
    return make_mapset_element(path, p_element);
}

/*!
   \brief Create element in the temporary directory.

   See G_file_name_tmp() for details.

   \param p_element element to be created in mapset

   \return 0 no element defined
   \return 1 on success
 */
int G_make_mapset_element_tmp(const char *p_element)
{
    char path[GPATH_MAX];
    
    G_file_name_tmp(path, NULL, NULL, G_mapset());
    return make_mapset_element(path, p_element);
}

int make_mapset_element(const char *p_path, const char *p_element)
{
    char path[GPATH_MAX], *p;
    const char *element;

    element = p_element;
    if (*element == 0)
	return 0;

    strncpy(path, p_path, GPATH_MAX);
    p = path;
    while (*p)
	p++;
    /* add trailing slash if missing */
    --p;
    if (*p++ != '/') {
	*p++ = '/';
	*p = 0;
    }

    /* now append element, one directory at a time, to path */
    while (1) {
	if (*element == '/' || *element == 0) {
	    *p = 0;
	    if (access(path, 0) != 0) { /* directory not yet created */
		if (G_mkdir(path) != 0)
		    G_fatal_error(_("Unable to make mapset element %s (%s): %s"),
				  p_element, path, strerror(errno));
	    }
	    if (access(path, 0) != 0)  /* directory not accessible */
		G_fatal_error(_("Unable to access mapset element %s (%s): %s"),
			      p_element, path, strerror(errno));
	    if (*element == 0)
		return 1;
	}
	*p++ = *element++;
    }
}

/*!
   \brief Create misc element in the current mapset.

   \param dir directory path
   \param name element to be created in mapset

   \return 0 no element defined
   \return 1 on success
 */
int G__make_mapset_element_misc(const char *dir, const char *name)
{
    char buf[GNAME_MAX * 2 + 1];

    sprintf(buf, "%s/%s", dir, name);
    return G_make_mapset_element(buf);
}

static int check_owner(const struct stat *info)
{
#if defined(__MINGW32__) || defined(SKIP_MAPSET_OWN_CHK)
    return 1;
#else
    const char *check = getenv("GRASS_SKIP_MAPSET_OWNER_CHECK");
    if (check && *check)
	return 1;
    if (info->st_uid != getuid())
	return 0;
    if (info->st_uid != geteuid())
	return 0;
    return 1;
#endif
}

/*!
   \brief Check for user mapset permission

   \param mapset mapset name

   \return 1 mapset exists, and user has permission
   \return 0 mapset exists, BUT user denied permission
   \return -1 mapset does not exist
 */
int G_mapset_permissions(const char *mapset)
{
    char path[GPATH_MAX];
    struct stat info;

    G_file_name(path, "", "", mapset);

    if (G_stat(path, &info) != 0)
	return -1;
    if (!S_ISDIR(info.st_mode))
	return -1;

    if (!check_owner(&info))
	return 0;

    return 1;
}

/*!
   \brief Check for user mapset permission

   \param gisdbase full path to GISDBASE
   \param location location name
   \param mapset mapset name

   \return 1 mapset exists, and user has permission
   \return 0 mapset exists, BUT user denied permission
   \return -1 mapset does not exist
 */
int G_mapset_permissions2(const char *gisdbase, const char *location,
			   const char *mapset)
{
    char path[GPATH_MAX];
    struct stat info;

    sprintf(path, "%s/%s/%s", gisdbase, location, mapset);

    if (G_stat(path, &info) != 0)
	return -1;
    if (!S_ISDIR(info.st_mode))
	return -1;

    if (!check_owner(&info))
	return 0;

    return 1;
}