com.maverick.sshd.vfs
Class VirtualFileSystem

java.lang.Object
  com.maverick.sshd.vfs.VirtualFileSystem

All Implemented Interfaces:

FileSystem

public class VirtualFileSystem
extends java.lang.Object
implements FileSystem

Provides a platform independent file system that uses standard java file operations. The virtual file system operates on a set of 'mounts' that map a virtual directory to a physical location on the server.

To configure the file system use the following code in your com.maverick.sshd.SshDaemon#configure(ConfigurationContext) implementation:

 context.setFileSystemProvider(VirtualFileSystem.class);
 

Mounts can be created by setting system properties and only one property is required "com.maverick.sshd.vfs.VFSRoot". This instructs the server where to look for the root of the file system "/". For example if you wanted to provide access to the root of a windows machine you could set the following property

 System.setProperty("com.maverick.sshd.vfs.VFSRoot", "C:\\");
 

Additional mounts can be set using "com.maverick.sshd.vfs.VFSMount.1" "com.maverick.sshd.vfs.VFSMount.2" and so forth. These mounts must start with a "/" and also have a descriptive name. For example to set the virtual path "/documents" you could use the following property:

 System.setProperty("com.maverick.sshd.vfs.VFSMount.1",
                "/documents=C:\\My Documents");
 

The setting of attributes is NOT supported within the virtual file system and by default users will have access to all files and folders. You can optionally implement your own VFSPermissionHandler that will enable you to restrict access to files based on user/group permissions. To configure the file system with your handler simply set the "com.maverick.sshd.vfs.VFSPermissionHandler" system property to the fully qualified class name of your class. This will be installed whenever an instance of the VirtualFileSystem is created.

The file system also maps the /home/USERNAME to the users home directory.

Author:

Lee David Painter

Field Summary

Fields inherited from interface com.maverick.sshd.platform.FileSystem

AUTHORIZED_KEYS_STORE, OPEN_APPEND, OPEN_CREATE, OPEN_EXCLUSIVE, OPEN_READ, OPEN_TRUNCATE, OPEN_WRITE, SCP, SFTP, SSH

Constructor Summary

VirtualFileSystem()

Method Summary

protected void	addMount(java.lang.String vfspath, java.lang.String nfspath)
void	closeFile(byte[] handle) Close an open file or directory.
boolean	closeFile(byte[] handle, boolean remove)
void	closeFilesystem() The filesystem instance is being closed and no further use of the instance is required.
void	createSymbolicLink(java.lang.String link, java.lang.String target) Create a symbolic link.
boolean	fileExists(java.lang.String path) Determine whether a file exists and return the result
java.lang.String	getDefaultPath() Get the default path for the current session.
SftpFileAttributes	getFileAttributes(byte[] handle) Get the attributes for a given file handle.
SftpFileAttributes	getFileAttributes(java.lang.String path) Get the attributes for a given file.
java.lang.String	getRealPath(java.lang.String path) Get the real path for a given path.
void	init(Connection con, java.lang.String protocolInUse)
boolean	makeDirectory(java.lang.String path) Create a directory.
byte[]	openDirectory(java.lang.String path) Open a directory for reading and allocate an open file handle.
byte[]	openFile(java.lang.String path, com.maverick.util.UnsignedInteger32 flags, SftpFileAttributes attrs) Open a file for reading/writing and allocate an open file handle.
SftpFile[]	readDirectory(byte[] handle) Read the contents of a directory.
int	readFile(byte[] handle, com.maverick.util.UnsignedInteger64 offset, byte[] buf, int start, int numBytesToRead) Read a block of data from an open file.
SftpFile	readSymbolicLink(java.lang.String path) Read the target location of a symbolic link.
void	removeDirectory(java.lang.String path) Remove an empty directory from the file system.
void	removeFile(java.lang.String path) Remove a file.
void	renameFile(java.lang.String oldpath, java.lang.String newpath) Rename a file.
void	setFileAttributes(byte[] handle, SftpFileAttributes attrs) Set the open files attributes
void	setFileAttributes(java.lang.String path, SftpFileAttributes attrs) Set the files attributes.
protected java.lang.String	translateCanonicalPath(java.lang.String path, java.lang.String securemount)
java.lang.String	translateNFSPath(java.lang.String nfspath)
java.lang.String	translateVFSPath(java.lang.String vfspath)
void	writeFile(byte[] handle, com.maverick.util.UnsignedInteger64 offset, byte[] data, int off, int len) Write a block of data to an open file.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VirtualFileSystem

public VirtualFileSystem()

Method Detail

init

public void init(Connection con,
                 java.lang.String protocolInUse)
          throws java.io.IOException

Throws:

java.io.IOException

addMount

protected void addMount(java.lang.String vfspath,
                        java.lang.String nfspath)
                 throws java.io.IOException

Throws:

java.io.IOException

closeFilesystem

public void closeFilesystem()

Description copied from interface: FileSystem

The filesystem instance is being closed and no further use of the instance is required.

Specified by:

closeFilesystem in interface FileSystem

translateNFSPath

public java.lang.String translateNFSPath(java.lang.String nfspath)
                                  throws java.io.IOException,
                                         java.io.FileNotFoundException

Throws:

java.io.IOException

java.io.FileNotFoundException

translateVFSPath

public java.lang.String translateVFSPath(java.lang.String vfspath)
                                  throws java.io.IOException,
                                         java.io.FileNotFoundException

Throws:

java.io.IOException

java.io.FileNotFoundException

translateCanonicalPath

protected java.lang.String translateCanonicalPath(java.lang.String path,
                                                  java.lang.String securemount)
                                           throws java.io.FileNotFoundException,
                                                  java.io.IOException

Throws:

java.io.FileNotFoundException

java.io.IOException

makeDirectory

public boolean makeDirectory(java.lang.String path)
                      throws PermissionDeniedException,
                             java.io.FileNotFoundException,
                             java.io.IOException

Description copied from interface: FileSystem

Create a directory. A false value should be returned if the file or directory with the specified path already exists.

Specified by:

makeDirectory in interface FileSystem

Parameters:

path - String the absolute path to the new directory.

Returns:

boolean true if the directory was created, false if the directory already exists.

Throws:

PermissionDeniedException - if the user cannot perform this operation.

java.io.FileNotFoundException - if the parent directory does not exist.

java.io.IOException

getFileAttributes

public SftpFileAttributes getFileAttributes(byte[] handle)
                                     throws java.io.IOException,
                                            InvalidHandleException

Description copied from interface: FileSystem

Get the attributes for a given file handle. This requires that you build a file attributes object based upon all the information that you can determine from the file whose open handle has been provided.

Specified by:

getFileAttributes in interface FileSystem

Parameters:

handle - byte[]

Returns:

SftpFileAttributes

Throws:

java.io.IOException

InvalidHandleException

getFileAttributes

public SftpFileAttributes getFileAttributes(java.lang.String path)
                                     throws java.io.IOException,
                                            java.io.FileNotFoundException

Description copied from interface: FileSystem

Get the attributes for a given file. This requires that you build a file attributes object based upon all the information that you can determine.

Specified by:

getFileAttributes in interface FileSystem

Parameters:

path - String the absolute path to the file

Returns:

SftpFileAttributes

Throws:

java.io.IOException

java.io.FileNotFoundException - if the file cannot be found

See Also:

com.maverick.sftp.SftpFileAttributes

openDirectory

public byte[] openDirectory(java.lang.String path)
                     throws PermissionDeniedException,
                            java.io.FileNotFoundException,
                            java.io.IOException

Description copied from interface: FileSystem

Open a directory for reading and allocate an open file handle. Open file handles can be whatever you require but the length of the handle string MUST NOT exceed 256 data bytes. Subsequent calls to readDirectory and closeFile will provide the handle returned from this method.

Specified by:

openDirectory in interface FileSystem

Parameters:

path - String

Returns:

byte[]

Throws:

PermissionDeniedException

java.io.FileNotFoundException

java.io.IOException

readDirectory

public SftpFile[] readDirectory(byte[] handle)
                         throws InvalidHandleException,
                                java.io.EOFException,
                                java.io.IOException

Description copied from interface: FileSystem

Read the contents of a directory. Each call to this method should return one or more file objects with full file attributes for each file. The client will call this method repeatedly until an EOFException is thrown indicating that there are no more files to read from the directory. If there are no files to list then the EOFException should be thrown upon first call.

IMPORTANT: Each SftpFile object should be initialized with the relative path of the file AND NOT the absolute path.

Specified by:

readDirectory in interface FileSystem

Parameters:

handle - byte[]

Returns:

SftpFile[] an array of SftpFile objects.

Throws:

InvalidHandleException - the handle supplied is invalid.

java.io.EOFException - thrown once all the files contained with the directory have been read.

java.io.IOException - an error occurred

openFile

public byte[] openFile(java.lang.String path,
                       com.maverick.util.UnsignedInteger32 flags,
                       SftpFileAttributes attrs)
                throws PermissionDeniedException,
                       java.io.FileNotFoundException,
                       java.io.IOException

Description copied from interface: FileSystem

Open a file for reading/writing and allocate an open file handle. Open file handles can be whatever you require but the length of the handle string MUST NOT exceed 256 data bytes. Subsequent calls to readDirectory and closeFile will provide the handle returned from this method. The method specifes one or more file open flags which determine which mode the file should be opened in.

Specified by:

openFile in interface FileSystem

Parameters:

path - String

flags - UnsignedInteger32

attrs - SftpFileAttributes

Returns:

byte[]

Throws:

PermissionDeniedException

java.io.FileNotFoundException

java.io.IOException

readFile

public int readFile(byte[] handle,
                    com.maverick.util.UnsignedInteger64 offset,
                    byte[] buf,
                    int start,
                    int numBytesToRead)
             throws InvalidHandleException,
                    java.io.EOFException,
                    java.io.IOException

Description copied from interface: FileSystem

Read a block of data from an open file. You should read from the file offset provided and write the data into the buffer array from the start position and return no more data than is requested by numBytesToRead; return the actual number of bytes read in the return value and if the file offset specified is passed EOF you should throw an EOFException.

Specified by:

readFile in interface FileSystem

Parameters:

handle - byte[]

offset - UnsignedInteger64

buf - byte[]

start - int

numBytesToRead - int

Returns:

int

Throws:

InvalidHandleException

java.io.EOFException

java.io.IOException

writeFile

public void writeFile(byte[] handle,
                      com.maverick.util.UnsignedInteger64 offset,
                      byte[] data,
                      int off,
                      int len)
               throws InvalidHandleException,
                      java.io.IOException

Description copied from interface: FileSystem

Write a block of data to an open file. You should write the data from the offset for as many bytes as are supplied.

Specified by:

writeFile in interface FileSystem

Parameters:

handle - byte[]

offset - UnsignedInteger64

data - byte[]

off - int

len - int

Throws:

InvalidHandleException

java.io.IOException

closeFile

public void closeFile(byte[] handle)
               throws InvalidHandleException,
                      java.io.IOException

Description copied from interface: FileSystem

Close an open file or directory.

Specified by:

closeFile in interface FileSystem

Parameters:

handle - byte[]

Throws:

InvalidHandleException

java.io.IOException

closeFile

public boolean closeFile(byte[] handle,
                         boolean remove)
                  throws InvalidHandleException,
                         java.io.IOException

Throws:

InvalidHandleException

java.io.IOException

removeFile

public void removeFile(java.lang.String path)
                throws PermissionDeniedException,
                       java.io.IOException,
                       java.io.FileNotFoundException

Description copied from interface: FileSystem

Remove a file.

Specified by:

removeFile in interface FileSystem

Parameters:

path - String

Throws:

PermissionDeniedException

java.io.IOException

java.io.FileNotFoundException

renameFile

public void renameFile(java.lang.String oldpath,
                       java.lang.String newpath)
                throws PermissionDeniedException,
                       java.io.FileNotFoundException,
                       java.io.IOException

Description copied from interface: FileSystem

Rename a file. It is an error if there already exists a file with the name specified by newpath.

Specified by:

renameFile in interface FileSystem

Parameters:

oldpath - String

newpath - String

Throws:

PermissionDeniedException

java.io.FileNotFoundException

java.io.IOException

getDefaultPath

public java.lang.String getDefaultPath()

Description copied from interface: FileSystem

Get the default path for the current session. The default path is normally the users home directory.

Specified by:

getDefaultPath in interface FileSystem

Returns:

String the absolute path to the default path.

removeDirectory

public void removeDirectory(java.lang.String path)
                     throws PermissionDeniedException,
                            java.io.FileNotFoundException,
                            java.io.IOException

Description copied from interface: FileSystem

Remove an empty directory from the file system. This method should fail if the directory has any file system objects as children.

Specified by:

removeDirectory in interface FileSystem

Parameters:

path - String

Throws:

PermissionDeniedException

java.io.FileNotFoundException

java.io.IOException

setFileAttributes

public void setFileAttributes(java.lang.String path,
                              SftpFileAttributes attrs)
                       throws PermissionDeniedException,
                              java.io.IOException,
                              java.io.FileNotFoundException

Description copied from interface: FileSystem

Set the files attributes.

Specified by:

setFileAttributes in interface FileSystem

Parameters:

path - String

attrs - SftpFileAttributes

Throws:

PermissionDeniedException

java.io.IOException

java.io.FileNotFoundException

setFileAttributes

public void setFileAttributes(byte[] handle,
                              SftpFileAttributes attrs)
                       throws PermissionDeniedException,
                              java.io.IOException,
                              InvalidHandleException

Description copied from interface: FileSystem

Set the open files attributes

Specified by:

setFileAttributes in interface FileSystem

Parameters:

handle - byte[]

attrs - SftpFileAttributes

Throws:

PermissionDeniedException

java.io.IOException

InvalidHandleException

readSymbolicLink

public SftpFile readSymbolicLink(java.lang.String path)
                          throws UnsupportedFileOperationException,
                                 java.io.FileNotFoundException,
                                 java.io.IOException,
                                 PermissionDeniedException

Description copied from interface: FileSystem

Read the target location of a symbolic link. If the file system does not support links then an UnsupportedOperationException should be thrown. Otherwise the full path to the target of the link should be returned.

Specified by:

readSymbolicLink in interface FileSystem

Parameters:

path - String

Returns:

SftpFile

Throws:

UnsupportedFileOperationException

java.io.FileNotFoundException

java.io.IOException

PermissionDeniedException

createSymbolicLink

public void createSymbolicLink(java.lang.String link,
                               java.lang.String target)
                        throws UnsupportedFileOperationException,
                               java.io.FileNotFoundException,
                               java.io.IOException,
                               PermissionDeniedException

Description copied from interface: FileSystem

Create a symbolic link. If the file system does not support the creation of links then an UnsupportedOperationException should be thrown.

Specified by:

createSymbolicLink in interface FileSystem

Parameters:

link - String

target - String

Throws:

UnsupportedFileOperationException

java.io.FileNotFoundException

java.io.IOException

PermissionDeniedException

fileExists

public boolean fileExists(java.lang.String path)
                   throws java.io.IOException

Description copied from interface: FileSystem

Determine whether a file exists and return the result

Specified by:

fileExists in interface FileSystem

Parameters:

path - String

Returns:

boolean true if the file exists, otherwise false.

Throws:

java.io.IOException

getRealPath

public java.lang.String getRealPath(java.lang.String path)
                             throws java.io.IOException,
                                    java.io.FileNotFoundException

Description copied from interface: FileSystem

Get the real path for a given path. This requires that the path be processed and a full path be returned, for example '/usr/../var' would be returned as '/var'. This should also expand relative paths using the users home directory as a base.

Specified by:

getRealPath in interface FileSystem

Parameters:

path - String the path to canonicalize.

Returns:

String the absolute path to the file.

Throws:

java.io.IOException - if an unrecoverable error occurs.

java.io.FileNotFoundException - if the path cannot be found.