encfs/encfs/DirNode.h

/*****************************************************************************
 * Author:   Valient Gough <vgough@pobox.com>
 *
 *****************************************************************************
 * Copyright (c) 2003, Valient Gough
 *
 * This program 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 3 of the License, or (at your
 * option) any later version.
 *
 * This program 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 program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _DirNode_incl_
#define _DirNode_incl_

#include <dirent.h>
#include <inttypes.h>
#include <list>
#include <map>
#include <memory>
#include <pthread.h>
#include <stdint.h>
#include <string>
#include <sys/types.h>
#include <vector>

#include "CipherKey.h"
#include "FSConfig.h"
#include "FileNode.h"
#include "NameIO.h"

namespace encfs {

class Cipher;
class EncFS_Context;
class FileNode;
class NameIO;
class RenameOp;
struct RenameEl;

class DirTraverse {
 public:
  DirTraverse(std::shared_ptr<DIR> dirPtr, uint64_t iv,
              std::shared_ptr<NameIO> naming, bool root);
  ~DirTraverse();

  DirTraverse &operator=(const DirTraverse &src);

  // returns FALSE to indicate an invalid DirTraverse (such as when
  // an invalid directory is requested for traversal)
  bool valid() const;

  // return next plaintext filename
  // If fileType is not 0, then it is used to return the filetype (or 0 if
  // unknown)
  std::string nextPlaintextName(int *fileType = 0, ino_t *inode = 0);

  /* Return cipher name of next undecodable filename..
     The opposite of nextPlaintextName(), as that skips undecodable names..
  */
  std::string nextInvalid();

 private:
  std::shared_ptr<DIR> dir;  // struct DIR
  // initialization vector to use.  Not very general purpose, but makes it
  // more efficient to support filename IV chaining..
  uint64_t iv;
  std::shared_ptr<NameIO> naming;
  bool root;
};
inline bool DirTraverse::valid() const { return dir.get() != 0; }

class DirNode {
 public:
  // sourceDir points to where raw files are stored
  DirNode(EncFS_Context *ctx, const std::string &sourceDir,
          const FSConfigPtr &config);
  ~DirNode();

  // return the path to the root directory
  std::string rootDirectory();

  // recursive lookup check
  bool touchesMountpoint(const char *realPath) const;

  // find files
  std::shared_ptr<FileNode> lookupNode(const char *plaintextName,
                                       const char *requestor);

  /*
      Combined lookupNode + node->open() call.  If the open fails, then the
      node is not retained.  If the open succeeds, then the node is returned.
  */
  std::shared_ptr<FileNode> openNode(const char *plaintextName,
                                     const char *requestor, int flags,
                                     int *openResult);

  std::string cipherPath(const char *plaintextPath);
  std::string cipherPathWithoutRoot(const char *plaintextPath);
  std::string plainPath(const char *cipherPath);

  // relative cipherPath is the same as cipherPath except that it doesn't
  // prepent the mount point.  That it, it doesn't return a fully qualified
  // name, just a relative path within the encrypted filesystem.
  std::string relativeCipherPath(const char *plaintextPath);

  /*
      Returns true if file names are dependent on the parent directory name.
      If a directory name is changed, then all the filenames must also be
      changed.
  */
  bool hasDirectoryNameDependency() const;

  // unlink the specified file
  int unlink(const char *plaintextName);

  // traverse directory
  DirTraverse openDir(const char *plainDirName);

  // uid and gid are used as the directory owner, only if not zero
  int mkdir(const char *plaintextPath, mode_t mode, uid_t uid = 0,
            gid_t gid = 0);

  int rename(const char *fromPlaintext, const char *toPlaintext);

  int link(const char *to, const char *from);

  // returns idle time of filesystem in seconds
  int idleSeconds();

 protected:
  /*
      notify that a file is being renamed.
      This renames the internal node, if any.  If the file is not open, then
      this call has no effect.
      Returns the FileNode if it was found.
  */
  std::shared_ptr<FileNode> renameNode(const char *from, const char *to);
  std::shared_ptr<FileNode> renameNode(const char *from, const char *to,
                                       bool forwardMode);

  /*
      when directory IV chaining is enabled, a directory can't be renamed
      without renaming all its contents as well.  recursiveRename should be
      called after renaming the directory, passing in the plaintext from and
      to paths.
  */
  std::shared_ptr<RenameOp> newRenameOp(const char *from, const char *to);

 private:
  friend class RenameOp;

  bool genRenameList(std::list<RenameEl> &list, const char *fromP,
                     const char *toP);

  std::shared_ptr<FileNode> findOrCreate(const char *plainName);

  pthread_mutex_t mutex;

  EncFS_Context *ctx;

  // passed in as configuration
  std::string rootDir;
  FSConfigPtr fsConfig;

  std::shared_ptr<NameIO> naming;
};

}  // namespace encfs

#endif