Package org.apache.sshd.sftp.server

Class SftpSubsystem

java.lang.Object

org.apache.sshd.common.util.logging.AbstractLoggingBean

org.apache.sshd.sftp.server.AbstractSftpSubsystemHelper

org.apache.sshd.sftp.server.SftpSubsystem

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Runnable, FileSystemAware, SessionContextHolder, SessionHolder<ServerSession>, ExecutorServiceCarrier, ChannelDataReceiver, ServerChannelSessionHolder, AsyncCommand, AsyncCommandErrorStreamAware, AsyncCommandInputStreamAware, AsyncCommandOutputStreamAware, AsyncCommandStreamsAware, Command, CommandDirectErrorStreamAware, CommandDirectInputStreamAware, CommandDirectOutputStreamAware, CommandDirectStreamsAware, CommandLifecycle, ServerSessionHolder, SftpErrorStatusDataHandlerProvider, SftpEventListenerManager, SftpFileSystemAccessorProvider, SftpSubsystemEnvironment, SftpSubsystemProxy, SftpUnsupportedAttributePolicyProvider

public class SftpSubsystem
extends AbstractSftpSubsystemHelper
implements Command, java.lang.Runnable, FileSystemAware, ExecutorServiceCarrier, AsyncCommand, ChannelDataReceiver

SFTP subsystem

Field Summary

Fields

Modifier and Type	Field	Description
protected Buffer	buffer
protected ExitCallback	callback
protected static Buffer	CLOSE
protected java.util.concurrent.atomic.AtomicBoolean	closed
protected java.nio.file.Path	defaultDir
protected Environment	env
protected CloseableExecutorService	executorService
protected java.util.Map<java.lang.String,byte[]>	extensions
protected int	fileHandleSize
protected java.nio.file.FileSystem	fileSystem
protected java.util.Map<java.lang.String,Handle>	handles
protected int	maxFileHandleRounds
protected IoOutputStream	out
protected java.util.concurrent.Future<?>	pendingFuture
protected Random	randomizer
protected java.util.concurrent.BlockingQueue<Buffer>	requests
protected java.util.concurrent.atomic.AtomicLong	requestsCount
private ServerSession	serverSession
protected int	version
protected byte[]	workBuf

Fields inherited from class org.apache.sshd.sftp.server.AbstractSftpSubsystemHelper

DEFAULT_ACL_SUPPORTED_MASK, DEFAULT_OPEN_SSH_EXTENSIONS, DEFAULT_OPEN_SSH_EXTENSIONS_NAMES, DEFAULT_SUPPORTED_CLIENT_EXTENSIONS

Fields inherited from class org.apache.sshd.common.util.logging.AbstractLoggingBean

log

Fields inherited from interface org.apache.sshd.sftp.server.SftpSubsystemEnvironment

ALL_SFTP_IMPL, HIGHER_SFTP_IMPL, LOWER_SFTP_IMPL, SUPPORTED_SFTP_VERSIONS

Constructor Summary

Constructors

Constructor	Description
SftpSubsystem(ChannelSession channel, SftpSubsystemConfigurator configurator)

Method Summary

Modifier and Type	Method	Description
void	close()
protected void	closeAllHandles()
protected void	createLink(int id, java.lang.String existingPath, java.lang.String linkPath, boolean symLink)
int	data(ChannelSession channel, byte[] buf, int start, int len)	Called when the server receives additional bytes from the client.
void	destroy(ChannelSession channel)	This method is called by the SSH server to destroy the command because the client has disconnected somehow.
protected void	doBlock(int id, java.lang.String handle, long offset, long length, int mask)
protected void	doCheckFileHash(int id, java.lang.String targetType, java.lang.String target, java.util.Collection<java.lang.String> algos, long startOffset, long length, int blockSize, Buffer buffer)
protected void	doClose(int id, java.lang.String handle)
protected void	doCopyData(int id, java.lang.String readHandle, long readOffset, long readLength, java.lang.String writeHandle, long writeOffset)
protected void	doFSetStat(int id, java.lang.String handle, java.util.Map<java.lang.String,?> attrs)
protected java.util.Map<java.lang.String,java.lang.Object>	doFStat(int id, java.lang.String handle, int flags)
protected void	doInit(Buffer buffer, int id)
protected byte[]	doMD5Hash(int id, java.lang.String targetType, java.lang.String target, long startOffset, long length, byte[] quickCheckHash)
protected java.lang.String	doOpen(int id, java.lang.String path, int pflags, int access, java.util.Map<java.lang.String,java.lang.Object> attrs)
protected java.lang.String	doOpenDir(int id, java.lang.String path, java.nio.file.Path dir, java.nio.file.LinkOption... options)
protected void	doOpenSSHFsync(int id, java.lang.String handle)
protected void	doProcess(Buffer buffer, int length, int type, int id)
protected int	doRead(int id, java.lang.String handle, long offset, int length, byte[] data, int doff, java.util.concurrent.atomic.AtomicReference<java.lang.Boolean> eof)
protected void	doReadDir(Buffer buffer, int id)
protected void	doTextSeek(int id, java.lang.String handle, long line)
protected void	doUnblock(int id, java.lang.String handle, long offset, long length)
protected void	doVersionSelect(Buffer buffer, int id, java.lang.String proposed)
protected void	doWrite(int id, java.lang.String handle, long offset, int length, byte[] data, int doff, int remaining)
protected java.lang.String	generateFileHandle(java.nio.file.Path file)
java.nio.file.Path	getDefaultDirectory()
CloseableExecutorService	getExecutorService()
ServerSession	getServerSession()
int	getVersion()
protected void	initializeSessionRelatedMember(ServerSession session, ChannelSession channel)
protected Buffer	prepareReply(Buffer buffer)
protected ChannelDataReceiver	resolveErrorDataChannelReceiver(ChannelSession channelSession, ChannelDataReceiver receiver)
void	run()
protected void	send(Buffer buffer)
void	setErrorStream(java.io.OutputStream err)	Set the error stream that can be used by the shell to write its errors.
void	setExitCallback(ExitCallback callback)	Set the callback that the shell has to call when it is closed.
void	setFileSystem(java.nio.file.FileSystem fileSystem)	Set the file system in which this shell will be executed.
void	setInputStream(java.io.InputStream in)	Set the input stream that can be used by the shell to read input.
void	setIoErrorStream(IoOutputStream err)	Set the error stream that can be used by the shell to write its errors.
void	setIoInputStream(IoInputStream in)	Set the input stream that can be used by the shell to read input.
void	setIoOutputStream(IoOutputStream out)	Set the output stream that can be used by the shell to write its output.
void	setOutputStream(java.io.OutputStream out)	Set the output stream that can be used by the shell to write its output.
void	start(ChannelSession channel, Environment env)	Starts the command execution.

Methods inherited from class org.apache.sshd.sftp.server.AbstractSftpSubsystemHelper

addMissingAttribute, addSftpEventListener, appendAclSupportedExtension, appendExtensions, appendNewlineExtension, appendOpenSSHExtensions, appendSupported2Extension, appendSupportedExtension, appendVendorIdExtension, appendVersionsExtension, checkVersionCompatibility, doBlock, doCheckFileHash, doCheckFileHash, doClose, doCopyData, doCopyFile, doCopyFile, doCopyFile, doExtended, doFSetStat, doFStat, doLink, doLink, doLStat, doLStat, doMakeDirectory, doMakeDirectory, doMD5Hash, doMD5Hash, doOpen, doOpenDir, doOpenSSHFsync, doOpenSSHHardLink, doOpenSSHHardLink, doPosixRename, doRead, doReadDir, doReadLink, doReadLink, doRealPath, doRealPathV345, doRealPathV6, doRemove, doRemove, doRemoveDirectory, doRemoveDirectory, doRemoveFile, doRename, doRename, doRename, doSetAttributes, doSetStat, doSetStat, doSpaceAvailable, doSpaceAvailable, doStat, doStat, doSymLink, doSymLink, doTextSeek, doUnblock, doUnsupported, doUnsupportedExtension, doVersionSelect, doWrite, executeExtendedCommand, getAttributes, getAttributes, getErrorStatusDataHandler, getFileSystemAccessor, getLongName, getLongName, getLongName, getLongName, getPathResolutionLinkOption, getServerChannelSession, getSftpEventListenerProxy, getShortName, getSupportedClientExtensions, getUnsupportedAttributePolicy, handleReadFileAttributesException, handleSetFileAttributeFailure, handleUnknownStatusFileAttributes, handleUnsupportedAttributes, handleUserPrincipalLookupServiceException, normalize, process, readAttrs, readFileAttributes, removeSftpEventListener, resolveAclSupportedCapabilities, resolveFile, resolveFileAttributes, resolveMissingFileAttributes, resolveMissingFileAttributeValue, resolveNewlineValue, resolveNormalizedLocation, resolveOpenSSHExtensions, resolvePathResolutionFollowLinks, resolveReportedFileAttributes, sendAttrs, sendHandle, sendLink, sendPath, sendStatus, sendStatus, sendStatus, setFileAccessControl, setFileAttribute, setFileAttributes, setFileExtensions, setFileOwnership, setFilePermissions, setFileRawViewAttribute, setFileTime, signalOpenFailure, signalRemovalPreConditionFailure, toGroup, toUser, validateHandle, validateProposedVersion, validateRealPath, writeAttrs, writeDirEntry, writeDirEntry

Methods inherited from class org.apache.sshd.common.util.logging.AbstractLoggingBean

debug, debug, debug, debug, debug, error, error, error, error, error, getSimplifiedLogger, info, info, warn, warn, warn, warn, warn, warn, warn, warn

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.sshd.common.file.FileSystemAware

setFileSystemFactory

Methods inherited from interface org.apache.sshd.common.session.SessionHolder

getSessionContext

Methods inherited from interface org.apache.sshd.sftp.server.SftpSubsystemEnvironment

getSession

Field Detail

CLOSE

protected static final Buffer CLOSE

closed

protected final java.util.concurrent.atomic.AtomicBoolean closed

requestsCount

protected final java.util.concurrent.atomic.AtomicLong requestsCount

extensions

protected final java.util.Map<java.lang.String,byte[]> extensions

handles

protected final java.util.Map<java.lang.String,Handle> handles

buffer

protected final Buffer buffer

requests

protected final java.util.concurrent.BlockingQueue<Buffer> requests

callback

protected ExitCallback callback

out

protected IoOutputStream out

env

protected Environment env

randomizer

protected Random randomizer

fileHandleSize

protected int fileHandleSize

maxFileHandleRounds

protected int maxFileHandleRounds

pendingFuture

protected java.util.concurrent.Future<?> pendingFuture

workBuf

protected byte[] workBuf

fileSystem

protected java.nio.file.FileSystem fileSystem

defaultDir

protected java.nio.file.Path defaultDir

version

protected int version

executorService

protected CloseableExecutorService executorService

serverSession

private final ServerSession serverSession

Constructor Detail

SftpSubsystem

public SftpSubsystem(ChannelSession channel,
                     SftpSubsystemConfigurator configurator)

Parameters:

channel - The ChannelSession through which the command was received

configurator - The SftpSubsystemConfigurator to use

Method Detail

resolveErrorDataChannelReceiver

protected ChannelDataReceiver resolveErrorDataChannelReceiver(ChannelSession channelSession,
                                                              ChannelDataReceiver receiver)

getVersion

public int getVersion()

Specified by:

getVersion in interface SftpSubsystemEnvironment

Returns:

The negotiated version

getDefaultDirectory

public java.nio.file.Path getDefaultDirectory()

Specified by:

getDefaultDirectory in interface SftpSubsystemEnvironment

Returns:

The default root directory used to resolve relative paths - a.k.a. the chroot location

getExecutorService

public CloseableExecutorService getExecutorService()

Specified by:

getExecutorService in interface ExecutorServiceCarrier

Returns:

The CloseableExecutorService to use

initializeSessionRelatedMember

protected void initializeSessionRelatedMember(ServerSession session,
                                              ChannelSession channel)

getServerSession

public ServerSession getServerSession()

Specified by:

getServerSession in interface ServerSessionHolder

Returns:

The underlying ServerSession used

setFileSystem

public void setFileSystem(java.nio.file.FileSystem fileSystem)

Description copied from interface: FileSystemAware

Set the file system in which this shell will be executed.

Specified by:

setFileSystem in interface FileSystemAware

Parameters:

fileSystem - the file system

setExitCallback

public void setExitCallback(ExitCallback callback)

Description copied from interface: Command

Set the callback that the shell has to call when it is closed.

Specified by:

setExitCallback in interface Command

Parameters:

callback - The ExitCallback to call when shell is closed

setInputStream

public void setInputStream(java.io.InputStream in)

Description copied from interface: CommandDirectInputStreamAware

Set the input stream that can be used by the shell to read input.

Specified by:

setInputStream in interface CommandDirectInputStreamAware

Parameters:

in - The InputStream used by the shell to read input.

setOutputStream

public void setOutputStream(java.io.OutputStream out)

Description copied from interface: CommandDirectOutputStreamAware

Set the output stream that can be used by the shell to write its output.

Specified by:

setOutputStream in interface CommandDirectOutputStreamAware

Parameters:

out - The OutputStream used by the shell to write its output

setErrorStream

public void setErrorStream(java.io.OutputStream err)

Description copied from interface: CommandDirectErrorStreamAware

Set the error stream that can be used by the shell to write its errors.

Specified by:

setErrorStream in interface CommandDirectErrorStreamAware

Parameters:

err - The OutputStream used by the shell to write its errors

setIoInputStream

public void setIoInputStream(IoInputStream in)

Description copied from interface: AsyncCommandInputStreamAware

Set the input stream that can be used by the shell to read input.

Specified by:

setIoInputStream in interface AsyncCommandInputStreamAware

Parameters:

in - The IoInputStream used by the shell to read input

setIoOutputStream

public void setIoOutputStream(IoOutputStream out)

Description copied from interface: AsyncCommandOutputStreamAware

Set the output stream that can be used by the shell to write its output.

Specified by:

setIoOutputStream in interface AsyncCommandOutputStreamAware

Parameters:

out - The IoOutputStream used by the shell to write its output

setIoErrorStream

public void setIoErrorStream(IoOutputStream err)

Description copied from interface: AsyncCommandErrorStreamAware

Set the error stream that can be used by the shell to write its errors.

Specified by:

setIoErrorStream in interface AsyncCommandErrorStreamAware

Parameters:

err - The IoOutputStream used by the shell to write its errors

start

public void start(ChannelSession channel,
                  Environment env)
           throws java.io.IOException

Description copied from interface: CommandLifecycle

Starts the command execution. All streams must have been set before calling this method. The command should implement Runnable, and this method should spawn a new thread like:

 Thread(this).start(); 
 

Specified by:

start in interface CommandLifecycle

Parameters:

channel - The ChannelSession through which the command has been received

env - The Environment

Throws:

java.io.IOException - If failed to start

data

public int data(ChannelSession channel,
                byte[] buf,
                int start,
                int len)
         throws java.io.IOException

Description copied from interface: ChannelDataReceiver

Called when the server receives additional bytes from the client. When Closeable.close()-d then indicates EOF - The client will no longer send us any more data.

SSH channels use the windowing mechanism to perform flow control, much like TCP does. The server gives the client the initial window size, which represents the number of bytes the client can send to the server. As the server receives data, it can send a message to the client to allow it to send more data.

The return value from this method is used to control this behaviour. Intuitively speaking, the callee returns the number of bytes consumed by this method, by the time this method returns. Picture a one-way long bridge (for example Golden Gate Bridge) with toll plazas on both sides. The window size is the maximum number of cars allowed on the bridge. Here we are on the receiving end, so our job here is to count the number of cars as it leaves the bridge, and if enough of them left, we'll signal the sending end that they can let in more cars. The return value of this method counts the number of cars that are leaving in this batch.

In simple cases, where the callee has consumed the bytes before it returns, the return value must be the same value as the 'len' parameter given.

On the other hand, if the callee is queueing up the received bytes somewhere to be consumed later (for example by another thread), then this method should return 0, for the bytes aren't really consumed yet. And when at some later point the bytes are actually used, then you'll invoke channel.getLocalWindow().consumeAndCheck(len) to let the channel know that bytes are consumed.

This behaviour will result in a better flow control, as the server will not allow the SSH client to overflow its buffer. If instead you always return the value passed in the 'len' parameter, the place where you are queueing up bytes may overflow.

In either case, the callee must account for every bytes it receives in this method. Returning 0 and failing to call back channel.getLocalWindow().consumeAndCheck(len) later will dry up the window size, and eventually the client will stop sending you any data.

In the SSH protocol, this method invocation is triggered by a SSH_MSG_CHANNEL_DATA message.

Specified by:

data in interface ChannelDataReceiver

Parameters:

channel - The caller to which this ChannelDataReceiver is assigned. Never null.

buf - Holds the bytes received. This buffer belongs to the caller, and it might get reused by the caller as soon as this method returns.

start - buf[start] is the first byte that received from the client.

len - the length of the bytes received. Can be zero.

Returns:

The number of bytes consumed, for the purpose of the flow control. For a simple use case, you return the value given by the 'len' parameter. See the method javadoc for more details.

Throws:

java.io.IOException - if failed to consume the data

run

public void run()

Specified by:

run in interface java.lang.Runnable

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

doProcess

protected void doProcess(Buffer buffer,
                         int length,
                         int type,
                         int id)
                  throws java.io.IOException

Overrides:

doProcess in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

createLink

protected void createLink(int id,
                          java.lang.String existingPath,
                          java.lang.String linkPath,
                          boolean symLink)
                   throws java.io.IOException

Specified by:

createLink in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doTextSeek

protected void doTextSeek(int id,
                          java.lang.String handle,
                          long line)
                   throws java.io.IOException

Specified by:

doTextSeek in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doOpenSSHFsync

protected void doOpenSSHFsync(int id,
                              java.lang.String handle)
                       throws java.io.IOException

Specified by:

doOpenSSHFsync in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doCheckFileHash

protected void doCheckFileHash(int id,
                               java.lang.String targetType,
                               java.lang.String target,
                               java.util.Collection<java.lang.String> algos,
                               long startOffset,
                               long length,
                               int blockSize,
                               Buffer buffer)
                        throws java.lang.Exception

Specified by:

doCheckFileHash in class AbstractSftpSubsystemHelper

Throws:

java.lang.Exception

doMD5Hash

protected byte[] doMD5Hash(int id,
                           java.lang.String targetType,
                           java.lang.String target,
                           long startOffset,
                           long length,
                           byte[] quickCheckHash)
                    throws java.lang.Exception

Specified by:

doMD5Hash in class AbstractSftpSubsystemHelper

Throws:

java.lang.Exception

doVersionSelect

protected void doVersionSelect(Buffer buffer,
                               int id,
                               java.lang.String proposed)
                        throws java.io.IOException

Specified by:

doVersionSelect in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doBlock

protected void doBlock(int id,
                       java.lang.String handle,
                       long offset,
                       long length,
                       int mask)
                throws java.io.IOException

Specified by:

doBlock in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doUnblock

protected void doUnblock(int id,
                         java.lang.String handle,
                         long offset,
                         long length)
                  throws java.io.IOException

Specified by:

doUnblock in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doCopyData

protected void doCopyData(int id,
                          java.lang.String readHandle,
                          long readOffset,
                          long readLength,
                          java.lang.String writeHandle,
                          long writeOffset)
                   throws java.io.IOException

Specified by:

doCopyData in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doReadDir

protected void doReadDir(Buffer buffer,
                         int id)
                  throws java.io.IOException

Specified by:

doReadDir in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doOpenDir

protected java.lang.String doOpenDir(int id,
                                     java.lang.String path,
                                     java.nio.file.Path dir,
                                     java.nio.file.LinkOption... options)
                              throws java.io.IOException

Specified by:

doOpenDir in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doFSetStat

protected void doFSetStat(int id,
                          java.lang.String handle,
                          java.util.Map<java.lang.String,?> attrs)
                   throws java.io.IOException

Specified by:

doFSetStat in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doFStat

protected java.util.Map<java.lang.String,java.lang.Object> doFStat(int id,
                                                                         java.lang.String handle,
                                                                         int flags)
                                                                  throws java.io.IOException

Specified by:

doFStat in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doWrite

protected void doWrite(int id,
                       java.lang.String handle,
                       long offset,
                       int length,
                       byte[] data,
                       int doff,
                       int remaining)
                throws java.io.IOException

Specified by:

doWrite in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doRead

protected int doRead(int id,
                     java.lang.String handle,
                     long offset,
                     int length,
                     byte[] data,
                     int doff,
                     java.util.concurrent.atomic.AtomicReference<java.lang.Boolean> eof)
              throws java.io.IOException

Specified by:

doRead in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doClose

protected void doClose(int id,
                       java.lang.String handle)
                throws java.io.IOException

Specified by:

doClose in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

doOpen

protected java.lang.String doOpen(int id,
                                  java.lang.String path,
                                  int pflags,
                                  int access,
                                  java.util.Map<java.lang.String,java.lang.Object> attrs)
                           throws java.io.IOException

Specified by:

doOpen in class AbstractSftpSubsystemHelper

Parameters:

id - Request id

path - Path

pflags - Open mode flags - see SSH_FXF_XXX flags

access - Access mode flags - see ACE4_XXX flags

attrs - Requested attributes

Returns:

The assigned (opaque) handle

Throws:

java.io.IOException - if failed to execute

generateFileHandle

protected java.lang.String generateFileHandle(java.nio.file.Path file)
                                       throws java.io.IOException

Throws:

java.io.IOException

doInit

protected void doInit(Buffer buffer,
                      int id)
               throws java.io.IOException

Specified by:

doInit in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

prepareReply

protected Buffer prepareReply(Buffer buffer)

Specified by:

prepareReply in class AbstractSftpSubsystemHelper

send

protected void send(Buffer buffer)
             throws java.io.IOException

Specified by:

send in class AbstractSftpSubsystemHelper

Throws:

java.io.IOException

destroy

public void destroy(ChannelSession channel)

Description copied from interface: CommandLifecycle

This method is called by the SSH server to destroy the command because the client has disconnected somehow.

Specified by:

destroy in interface CommandLifecycle

Parameters:

channel - The ChannelSession through which the command has been received

closeAllHandles

protected void closeAllHandles()