libsefs-dev 3.3.6.ds-7.2ubuntu4 / usr / include / sefs / filesystem.hh

/**
 *  @file
 *  Defines the public interface for the filesystem fc list object.
 *
 *  @author Jeremy A. Mowery jmowery@tresys.com
 *  @author Jason Tang jtang@tresys.com
 *
 *  Copyright (C) 2007 Tresys Technology, LLC
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef SEFS_FILESYSTEM_H
#define SEFS_FILESYSTEM_H

#include <sefs/fclist.hh>

#ifdef __cplusplus
extern "C"
{
#endif

#include <apol/vector.h>

#ifdef __cplusplus
}

#include <stdexcept>

/**
 * This class represents the SELinux file contexts on a local on-disk
 * filesystem.  Be aware that the object will recurse beginning from
 * the root directory, so if there are circular mounts (e.g., via
 * something mounted with the 'bind' option) then queries against the
 * filesystem will never terminate.
 */
class sefs_filesystem:public sefs_fclist
{
#ifndef SWIG_FRIENDS
	// private functions -- do not call these directly from
	// outside of the library
	friend struct sefs_context_node *filesystem_get_context(sefs_filesystem *, security_context_t) throw(std::bad_alloc);
	friend sefs_entry *filesystem_get_entry(sefs_filesystem *, const struct sefs_context_node *, uint32_t,
						const char *, ino64_t, const char *) throw(std::bad_alloc);
	friend bool filesystem_is_query_match(sefs_filesystem *, const sefs_query *, const char *, const char *,
					      const struct stat64 *, apol_vector_t *, apol_mls_range_t *) throw(std::runtime_error);
#endif

      public:

	/**
	 * Allocate and return a new sefs filesystem structure
	 * representing the filesystem rooted at directory \a root.
	 * <b>Be aware that the constructor is not thread-safe.</b>
	 * @param new_root Directory to use as the root of the
	 * filesystem.  This object represents this directory and all
	 * subdirectories, including other mounted filesystems.
	 * @param msg_callback Callback to invoke as errors/warnings
	 * are generated.  If NULL, write messages to standard error.
	 * @param varg Value to be passed as the first parameter to
	 * the callback function.
	 * @exception bad_alloc Out of memory.
	 * @exception invalid_argument Root directory does not exist.
	 * @exception runtime_error Could not open root directory or
	 * /etc/mtab.
	 */
	 sefs_filesystem(const char *new_root, sefs_callback_fn_t msg_callback, void *varg) throw(std::bad_alloc,
												  std::invalid_argument,
												  std::runtime_error);

	~sefs_filesystem();

	/**
	 * Perform a sefs query on this filesystem object, and then
	 * invoke a callback upon each matching entry.  Mapping is in
	 * pre-order (i.e., directories will be mapped prior to files
	 * and subdirectories they contain.)
	 * @param query Query object containing search parameters.  If
	 * NULL, invoke the callback on all entries.
	 * @param fn Function to invoke upon matching entries.  This
	 * function will be called with three parameters: a pointer to
	 * this filesystem, pointer to a matching entry, and an
	 * arbitrary data pointer.  It should return a non-negative
	 * value upon success, negative value upon error and to abort
	 * the mapping.
	 * @param data Arbitrary pointer to be passed into \fn as a
	 * third parameter.
	 * @return Last value returned by fn() (i.e., >= on success, <
	 * 0 on failure).  If the filesystem has no entries then
	 * return 0.
	 * @exception std::runtime_error Error while reading contexts
	 * from the filesystem.
	 * @exception std::invalid_argument One or more query arguments
	 * is invalid.
	 */
	int runQueryMap(sefs_query * query, sefs_fclist_map_fn_t fn, void *data) throw(std::runtime_error, std::invalid_argument);

	/**
	 * Determine if the contexts stored in this filesystem contain
	 * MLS fields.
	 * @return \a true if MLS fields are present, \a false if not
	 * or undeterminable.
	 */
	bool isMLS() const;

	/**
	 * Get the root directory of a sefs filesystem structure.
	 * @return The root directory of the filesystem or NULL on
	 * error.  Do not free() this string.
	 */
	const char *root() const;

	/**
	 * Look up the given device number on the currently running
	 * system, and convert it to its device name.
	 * @param dev Device number to look up.
	 * @return Name of the device, or NULL if the device number
	 * was not found.  Do not free() this pointer.
	 * @exception std::runtime_error Error while querying system.
	 */
	const char *getDevName(const dev_t dev) throw(std::runtime_error);

      private:
	 apol_vector_t * buildDevMap(void) throw(std::runtime_error);
	bool isQueryMatch(const sefs_query * query, const char *path, const char *dev, const struct stat64 *sb,
			  apol_vector_t * type_list, apol_mls_range_t * range) throw(std::runtime_error);
	sefs_entry *getEntry(const struct sefs_context_node *context, uint32_t objectClass, const char *path, ino64_t ino,
			     const char *dev_name) throw(std::bad_alloc);
	char *_root;
	bool _rw, _mls;
};

extern "C"
{
#endif

//we do not want to wrap two copies of everything so have SWIG ignore
//the compatibility section.
#ifndef SWIG

	typedef struct sefs_filesystem sefs_filesystem_t;

/**
 * Allocate and return a new sefs filesystem structure representing
 * the filesystem rooted at directory \a root.
 * @see sefs_filesystem::sefs_filesystem()
 */
	extern sefs_filesystem_t *sefs_filesystem_create(const char *root, sefs_callback_fn_t msg_callback, void *varg);

/**
 * Get the root directory of a sefs filesystem structure.
 * @see sefs_filesystem::root()
 */
	extern const char *sefs_filesystem_get_root(const sefs_filesystem_t * fs);

/**
 * Look up the given device number on the currently running
 * system, and convert it to its device name.
 * @see sefs_filesystem::ged_dev_name()
 */
	extern const char *sefs_filesystem_get_dev_name(sefs_filesystem_t * fs, const dev_t dev);

#endif				       /* SWIG */

#ifdef __cplusplus
}
#endif

#endif				       /* SEFS_FILESYSTEM_H */