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/*
 * Copyright (c) 2006-2011 Christian Plattner. All rights reserved.
 * Please refer to the LICENSE.txt for licensing details.
 */
package ch.ethz.ssh2;

import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.SocketException;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import ch.ethz.ssh2.channel.Channel;
import ch.ethz.ssh2.log.Logger;
import ch.ethz.ssh2.packets.TypesReader;
import ch.ethz.ssh2.packets.TypesWriter;
import ch.ethz.ssh2.sftp.AttribFlags;
import ch.ethz.ssh2.sftp.ErrorCodes;
import ch.ethz.ssh2.sftp.Packet;

/**
 * A SFTPv3Client represents a SFTP (protocol version 3)
 * client connection tunnelled over a SSH-2 connection. This is a very simple
 * (synchronous) implementation.
 * 

* Basically, most methods in this class map directly to one of * the packet types described in draft-ietf-secsh-filexfer-02.txt. *

* Note: this is experimental code. *

* Error handling: the methods of this class throw IOExceptions. However, unless * there is catastrophic failure, exceptions of the type {@link SFTPv3Client} will * be thrown (a subclass of IOException). Therefore, you can implement more verbose * behavior by checking if a thrown exception if of this type. If yes, then you * can cast the exception and access detailed information about the failure. *

* Notes about file names, directory names and paths, copy-pasted * from the specs: *

    *
  • SFTP v3 represents file names as strings. File names are * assumed to use the slash ('/') character as a directory separator.
  • *
  • File names starting with a slash are "absolute", and are relative to * the root of the file system. Names starting with any other character * are relative to the user's default directory (home directory).
  • *
  • Servers SHOULD interpret a path name component ".." as referring to * the parent directory, and "." as referring to the current directory. * If the server implementation limits access to certain parts of the * file system, it must be extra careful in parsing file names when * enforcing such restrictions. There have been numerous reported * security bugs where a ".." in a path name has allowed access outside * the intended area.
  • *
  • An empty path name is valid, and it refers to the user's default * directory (usually the user's home directory).
  • *
*

* If you are still not tired then please go on and read the comment for * {@link #setCharset(String)}. * * @author Christian Plattner, [email protected] * @version $Id: SFTPv3Client.java 99 2014-04-10 09:04:31Z [email protected] $ */ public class SFTPv3Client { private static final Logger log = Logger.getLogger(SFTPv3Client.class); private Session sess; private InputStream is; private OutputStream os; private int protocol_version = 0; private int next_request_id = 1000; private String charsetName = null; /** * */ private PacketListener listener; /** * Create a SFTP v3 client. * * @param conn The underlying SSH-2 connection to be used. * @throws IOException */ public SFTPv3Client(Connection conn, PacketListener listener) throws IOException { if (conn == null) { throw new IllegalArgumentException("Cannot accept null argument!"); } this.listener = listener; log.debug("Opening session and starting SFTP subsystem."); sess = conn.openSession(); sess.startSubSystem("sftp"); is = sess.getStdout(); os = new BufferedOutputStream(sess.getStdin(), 2048); if (is == null) { throw new IOException("There is a problem with the streams of the underlying channel."); } init(); } /** * Create a SFTP v3 client. * * @param conn The underlying SSH-2 connection to be used. * @throws IOException */ public SFTPv3Client(Connection conn) throws IOException { this(conn, new PacketListener() { public void read(String packet) { log.debug("Read packet " + packet); } public void write(String packet) { log.debug("Write packet " + packet); } }); } /** * Set the charset used to convert between Java Unicode Strings and byte encodings * used by the server for paths and file names. Unfortunately, the SFTP v3 draft * says NOTHING about such conversions (well, with the exception of error messages * which have to be in UTF-8). Newer drafts specify to use UTF-8 for file names * (if I remember correctly). However, a quick test using OpenSSH serving a EXT-3 * filesystem has shown that UTF-8 seems to be a bad choice for SFTP v3 (tested with * filenames containing german umlauts). "windows-1252" seems to work better for Europe. * Luckily, "windows-1252" is the platform default in my case =). *

* If you don't set anything, then the platform default will be used (this is the default * behavior). * * @param charset the name of the charset to be used or null to use the platform's * default encoding. * @throws IOException * @see #getCharset() */ public void setCharset(String charset) throws IOException { if (charset == null) { charsetName = null; return; } try { Charset.forName(charset); } catch (UnsupportedCharsetException e) { throw new IOException("This charset is not supported", e); } charsetName = charset; } /** * The currently used charset for filename encoding/decoding. * * @return The name of the charset (null if the platform's default charset is being used) * @see #setCharset(String) */ public String getCharset() { return charsetName; } private void checkHandleValidAndOpen(SFTPv3FileHandle handle) throws IOException { if (handle.client != this) { throw new IOException("The file handle was created with another SFTPv3FileHandle instance."); } if (handle.isClosed) { throw new IOException("The file handle is closed."); } } private void sendMessage(int type, int requestId, byte[] msg, int off, int len) throws IOException { listener.write(Packet.forName(type)); int msglen = len + 1; if (type != Packet.SSH_FXP_INIT) { msglen += 4; } os.write(msglen >> 24); os.write(msglen >> 16); os.write(msglen >> 8); os.write(msglen); os.write(type); if (type != Packet.SSH_FXP_INIT) { os.write(requestId >> 24); os.write(requestId >> 16); os.write(requestId >> 8); os.write(requestId); } os.write(msg, off, len); os.flush(); } private void sendMessage(int type, int requestId, byte[] msg) throws IOException { sendMessage(type, requestId, msg, 0, msg.length); } private void readBytes(byte[] buff, int pos, int len) throws IOException { while (len > 0) { int count = is.read(buff, pos, len); if (count < 0) { throw new SocketException("Unexpected end of sftp stream."); } if ((count == 0) || (count > len)) { throw new SocketException("Underlying stream implementation is bogus!"); } len -= count; pos += count; } } /** * Read a message and guarantee that the contents is not larger than * maxlen bytes. *

* Note: receiveMessage(34000) actually means that the message may be up to 34004 * bytes (the length attribute preceeding the contents is 4 bytes). * * @param maxlen * @return the message contents * @throws IOException */ private byte[] receiveMessage(int maxlen) throws IOException { byte[] msglen = new byte[4]; readBytes(msglen, 0, 4); int len = (((msglen[0] & 0xff) << 24) | ((msglen[1] & 0xff) << 16) | ((msglen[2] & 0xff) << 8) | (msglen[3] & 0xff)); if ((len > maxlen) || (len <= 0)) { throw new IOException("Illegal sftp packet len: " + len); } byte[] msg = new byte[len]; readBytes(msg, 0, len); return msg; } private int generateNextRequestID() { synchronized (this) { return next_request_id++; } } private void closeHandle(byte[] handle) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(handle, 0, handle.length); sendMessage(Packet.SSH_FXP_CLOSE, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } private SFTPv3FileAttributes readAttrs(TypesReader tr) throws IOException { /* * uint32 flags * uint64 size present only if flag SSH_FILEXFER_ATTR_SIZE * uint32 uid present only if flag SSH_FILEXFER_ATTR_V3_UIDGID * uint32 gid present only if flag SSH_FILEXFER_ATTR_V3_UIDGID * uint32 permissions present only if flag SSH_FILEXFER_ATTR_PERMISSIONS * uint32 atime present only if flag SSH_FILEXFER_ATTR_V3_ACMODTIME * uint32 mtime present only if flag SSH_FILEXFER_ATTR_V3_ACMODTIME * uint32 extended_count present only if flag SSH_FILEXFER_ATTR_EXTENDED * string extended_type * string extended_data * ... more extended data (extended_type - extended_data pairs), * so that number of pairs equals extended_count */ SFTPv3FileAttributes fa = new SFTPv3FileAttributes(); int flags = tr.readUINT32(); if ((flags & AttribFlags.SSH_FILEXFER_ATTR_SIZE) != 0) { log.debug("SSH_FILEXFER_ATTR_SIZE"); fa.size = tr.readUINT64(); } if ((flags & AttribFlags.SSH_FILEXFER_ATTR_V3_UIDGID) != 0) { log.debug("SSH_FILEXFER_ATTR_V3_UIDGID"); fa.uid = tr.readUINT32(); fa.gid = tr.readUINT32(); } if ((flags & AttribFlags.SSH_FILEXFER_ATTR_PERMISSIONS) != 0) { log.debug("SSH_FILEXFER_ATTR_PERMISSIONS"); fa.permissions = tr.readUINT32(); } if ((flags & AttribFlags.SSH_FILEXFER_ATTR_V3_ACMODTIME) != 0) { log.debug("SSH_FILEXFER_ATTR_V3_ACMODTIME"); fa.atime = tr.readUINT32(); fa.mtime = tr.readUINT32(); } if ((flags & AttribFlags.SSH_FILEXFER_ATTR_EXTENDED) != 0) { int count = tr.readUINT32(); log.debug("SSH_FILEXFER_ATTR_EXTENDED (" + count + ")"); /* Read it anyway to detect corrupt packets */ while (count > 0) { tr.readByteString(); tr.readByteString(); count--; } } return fa; } /** * Retrieve the file attributes of an open file. * * @param handle a SFTPv3FileHandle handle. * @return a SFTPv3FileAttributes object. * @throws IOException */ public SFTPv3FileAttributes fstat(SFTPv3FileHandle handle) throws IOException { checkHandleValidAndOpen(handle); int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(handle.fileHandle, 0, handle.fileHandle.length); log.debug("Sending SSH_FXP_FSTAT..."); sendMessage(Packet.SSH_FXP_FSTAT, req_id, tw.getBytes()); byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != req_id) { throw new RequestMismatchException(); } if (t == Packet.SSH_FXP_ATTRS) { return readAttrs(tr); } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } private SFTPv3FileAttributes statBoth(String path, int statMethod) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(path, charsetName); log.debug("Sending SSH_FXP_STAT/SSH_FXP_LSTAT..."); sendMessage(statMethod, req_id, tw.getBytes()); byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != req_id) { throw new RequestMismatchException(); } if (t == Packet.SSH_FXP_ATTRS) { return readAttrs(tr); } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } /** * Retrieve the file attributes of a file. This method * follows symbolic links on the server. * * @param path See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileAttributes object. * @throws IOException * @see #lstat(String) */ public SFTPv3FileAttributes stat(String path) throws IOException { return statBoth(path, Packet.SSH_FXP_STAT); } /** * Retrieve the file attributes of a file. This method * does NOT follow symbolic links on the server. * * @param path See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileAttributes object. * @throws IOException * @see #stat(String) */ public SFTPv3FileAttributes lstat(String path) throws IOException { return statBoth(path, Packet.SSH_FXP_LSTAT); } /** * Read the target of a symbolic link. Note: OpenSSH (as of version 4.4) gets very upset * (SSH_FX_BAD_MESSAGE error) if you want to read the target of a file that is not a * symbolic link. Better check first with {@link #lstat(String)}. * * @param path See the {@link SFTPv3Client comment} for the class for more details. * @return The target of the link. * @throws IOException */ public String readLink(String path) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(path, charsetName); log.debug("Sending SSH_FXP_READLINK..."); sendMessage(Packet.SSH_FXP_READLINK, req_id, tw.getBytes()); byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != req_id) { throw new RequestMismatchException(); } if (t == Packet.SSH_FXP_NAME) { int count = tr.readUINT32(); if (count != 1) { throw new IOException("The server sent an invalid SSH_FXP_NAME packet."); } return tr.readString(charsetName); } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } private void expectStatusOKMessage(int id) throws IOException { byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != id) { throw new RequestMismatchException(); } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); if (errorCode == ErrorCodes.SSH_FX_OK) { return; } String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } /** * Modify the attributes of a file. Used for operations such as changing * the ownership, permissions or access times, as well as for truncating a file. * * @param path See the {@link SFTPv3Client comment} for the class for more details. * @param attr A SFTPv3FileAttributes object. Specifies the modifications to be * made to the attributes of the file. Empty fields will be ignored. * @throws IOException */ public void setstat(String path, SFTPv3FileAttributes attr) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(path, charsetName); tw.writeBytes(createAttrs(attr)); log.debug("Sending SSH_FXP_SETSTAT..."); sendMessage(Packet.SSH_FXP_SETSTAT, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } /** * Modify the attributes of a file. Used for operations such as changing * the ownership, permissions or access times, as well as for truncating a file. * * @param handle a SFTPv3FileHandle handle * @param attr A SFTPv3FileAttributes object. Specifies the modifications to be * made to the attributes of the file. Empty fields will be ignored. * @throws IOException */ public void fsetstat(SFTPv3FileHandle handle, SFTPv3FileAttributes attr) throws IOException { checkHandleValidAndOpen(handle); int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(handle.fileHandle, 0, handle.fileHandle.length); tw.writeBytes(createAttrs(attr)); log.debug("Sending SSH_FXP_FSETSTAT..."); sendMessage(Packet.SSH_FXP_FSETSTAT, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } /** * Create a symbolic link on the server. Creates a link "src" that points * to "target". * * @param src See the {@link SFTPv3Client comment} for the class for more details. * @param target See the {@link SFTPv3Client comment} for the class for more details. * @throws IOException */ public void createSymlink(String src, String target) throws IOException { int req_id = generateNextRequestID(); /* Either I am too stupid to understand the SFTP draft * or the OpenSSH guys changed the semantics of src and target. */ TypesWriter tw = new TypesWriter(); tw.writeString(target, charsetName); tw.writeString(src, charsetName); log.debug("Sending SSH_FXP_SYMLINK..."); sendMessage(Packet.SSH_FXP_SYMLINK, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } /** * Have the server canonicalize any given path name to an absolute path. * This is useful for converting path names containing ".." components or * relative pathnames without a leading slash into absolute paths. * * @param path See the {@link SFTPv3Client comment} for the class for more details. * @return An absolute path. * @throws IOException */ public String canonicalPath(String path) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(path, charsetName); log.debug("Sending SSH_FXP_REALPATH..."); sendMessage(Packet.SSH_FXP_REALPATH, req_id, tw.getBytes()); byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != req_id) { throw new RequestMismatchException(); } if (t == Packet.SSH_FXP_NAME) { int count = tr.readUINT32(); if (count != 1) { throw new IOException("The server sent an invalid SSH_FXP_NAME packet."); } final String name = tr.readString(charsetName); listener.read(name); return name; } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } private List scanDirectory(byte[] handle) throws IOException { List files = new ArrayList(); while (true) { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(handle, 0, handle.length); log.debug("Sending SSH_FXP_READDIR..."); sendMessage(Packet.SSH_FXP_READDIR, req_id, tw.getBytes()); byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != req_id) { throw new RequestMismatchException(); } if (t == Packet.SSH_FXP_NAME) { int count = tr.readUINT32(); log.debug("Parsing " + count + " name entries..."); while (count > 0) { SFTPv3DirectoryEntry dirEnt = new SFTPv3DirectoryEntry(); dirEnt.filename = tr.readString(charsetName); dirEnt.longEntry = tr.readString(charsetName); listener.read(dirEnt.longEntry); dirEnt.attributes = readAttrs(tr); files.add(dirEnt); log.debug("File: '" + dirEnt.filename + "'"); count--; } continue; } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); if (errorCode == ErrorCodes.SSH_FX_EOF) { return files; } String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } } public final SFTPv3FileHandle openDirectory(String path) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(path, charsetName); log.debug("Sending SSH_FXP_OPENDIR..."); sendMessage(Packet.SSH_FXP_OPENDIR, req_id, tw.getBytes()); byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != req_id) { throw new RequestMismatchException(); } if (t == Packet.SSH_FXP_HANDLE) { log.debug("Got SSH_FXP_HANDLE."); return new SFTPv3FileHandle(this, tr.readByteString()); } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } private String expandString(byte[] b, int off, int len) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < len; i++) { int c = b[off + i] & 0xff; if ((c >= 32) && (c <= 126)) { sb.append((char) c); } else { sb.append(String.format("{0x%s}", Integer.toHexString(c))); } } return sb.toString(); } private void init() throws IOException { /* Send SSH_FXP_INIT (version 3) */ final int client_version = 3; log.debug("Sending SSH_FXP_INIT (" + client_version + ")..."); TypesWriter tw = new TypesWriter(); tw.writeUINT32(client_version); sendMessage(Packet.SSH_FXP_INIT, 0, tw.getBytes()); /* Receive SSH_FXP_VERSION */ log.debug("Waiting for SSH_FXP_VERSION..."); TypesReader tr = new TypesReader(receiveMessage(34000)); /* Should be enough for any reasonable server */ int t = tr.readByte(); listener.read(Packet.forName(t)); if (t != Packet.SSH_FXP_VERSION) { throw new IOException("The server did not send a SSH_FXP_VERSION packet (got " + t + ")"); } protocol_version = tr.readUINT32(); log.debug("SSH_FXP_VERSION: protocol_version = " + protocol_version); if (protocol_version != 3) { throw new IOException("Server version " + protocol_version + " is currently not supported"); } /* Read and save extensions (if any) for later use */ while (tr.remain() != 0) { String name = tr.readString(); listener.read(name); byte[] value = tr.readByteString(); log.debug("SSH_FXP_VERSION: extension: " + name + " = '" + expandString(value, 0, value.length) + "'"); } } /** * Returns the negotiated SFTP protocol version between the client and the server. * * @return SFTP protocol version, i.e., "3". */ public int getProtocolVersion() { return protocol_version; } /** * Queries the channel state * @return True if the underlying session is in open state */ public boolean isConnected() { return sess.getState() == Channel.STATE_OPEN; } /** * Close this SFTP session. NEVER forget to call this method to free up * resources - even if you got an exception from one of the other methods. * Sometimes these other methods may throw an exception, saying that the * underlying channel is closed (this can happen, e.g., if the other server * sent a close message.) However, as long as you have not called the * close() method, you are likely wasting resources. */ public void close() { sess.close(); } /** * List the contents of a directory. * * @param dirName See the {@link SFTPv3Client comment} for the class for more details. * @return A Vector containing {@link SFTPv3DirectoryEntry} objects. * @throws IOException */ public List ls(String dirName) throws IOException { SFTPv3FileHandle handle = openDirectory(dirName); List result = scanDirectory(handle.fileHandle); closeFile(handle); return result; } /** * Create a new directory. * * @param dirName See the {@link SFTPv3Client comment} for the class for more details. * @param posixPermissions the permissions for this directory, e.g., "0700" (remember that * this is octal noation). The server will likely apply a umask. * @throws IOException */ public void mkdir(String dirName, int posixPermissions) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(dirName, charsetName); tw.writeUINT32(AttribFlags.SSH_FILEXFER_ATTR_PERMISSIONS); tw.writeUINT32(posixPermissions); sendMessage(Packet.SSH_FXP_MKDIR, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } /** * Remove a file. * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @throws IOException */ public void rm(String fileName) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(fileName, charsetName); sendMessage(Packet.SSH_FXP_REMOVE, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } /** * Remove an empty directory. * * @param dirName See the {@link SFTPv3Client comment} for the class for more details. * @throws IOException */ public void rmdir(String dirName) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(dirName, charsetName); sendMessage(Packet.SSH_FXP_RMDIR, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } /** * Move a file or directory. * * @param oldPath See the {@link SFTPv3Client comment} for the class for more details. * @param newPath See the {@link SFTPv3Client comment} for the class for more details. * @throws IOException */ public void mv(String oldPath, String newPath) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(oldPath, charsetName); tw.writeString(newPath, charsetName); sendMessage(Packet.SSH_FXP_RENAME, req_id, tw.getBytes()); expectStatusOKMessage(req_id); } /** * Open the file for reading. */ public static final int SSH_FXF_READ = 0x00000001; /** * Open the file for writing. If both this and SSH_FXF_READ are * specified, the file is opened for both reading and writing. */ public static final int SSH_FXF_WRITE = 0x00000002; /** * Force all writes to append data at the end of the file. */ public static final int SSH_FXF_APPEND = 0x00000004; /** * If this flag is specified, then a new file will be created if one * does not alread exist (if O_TRUNC is specified, the new file will * be truncated to zero length if it previously exists). */ public static final int SSH_FXF_CREAT = 0x00000008; /** * Forces an existing file with the same name to be truncated to zero * length when creating a file by specifying SSH_FXF_CREAT. * SSH_FXF_CREAT MUST also be specified if this flag is used. */ public static final int SSH_FXF_TRUNC = 0x00000010; /** * Causes the request to fail if the named file already exists. */ public static final int SSH_FXF_EXCL = 0x00000020; /** * Open a file for reading. * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle openFileRO(String fileName) throws IOException { return openFile(fileName, SSH_FXF_READ, null); } /** * Open a file for reading and writing. * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle openFileRW(String fileName) throws IOException { return openFile(fileName, SSH_FXF_READ | SSH_FXF_WRITE, null); } /** * Open a file in append mode. The SFTP v3 draft says nothing but assuming normal POSIX * behavior, all writes will be appendend to the end of the file, no matter which offset * one specifies. *

* A side note for the curious: OpenSSH does an lseek() to the specified writing offset before each write(), * even for writes to files opened in O_APPEND mode. However, bear in mind that when working * in the O_APPEND mode, each write() includes an implicit lseek() to the end of the file * (well, this is what the newsgroups say). * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle openFileRWAppend(String fileName) throws IOException { return openFile(fileName, SSH_FXF_READ | SSH_FXF_WRITE | SSH_FXF_APPEND, null); } /** * Open a file in append mode. The SFTP v3 draft says nothing but assuming normal POSIX * behavior, all writes will be appendend to the end of the file, no matter which offset * one specifies. *

* A side note for the curious: OpenSSH does an lseek() to the specified writing offset before each write(), * even for writes to files opened in O_APPEND mode. However, bear in mind that when working * in the O_APPEND mode, each write() includes an implicit lseek() to the end of the file * (well, this is what the newsgroups say). * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle openFileWAppend(String fileName) throws IOException { return openFile(fileName, SSH_FXF_WRITE | SSH_FXF_APPEND, null); } /** * Create a file and open it for reading and writing. * Same as {@link #createFile(String, SFTPv3FileAttributes) createFile(fileName, null)}. * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle createFile(String fileName) throws IOException { return createFile(fileName, null); } /** * Create a file and open it for reading and writing. * You can specify the default attributes of the file (the server may or may * not respect your wishes). * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @param attr may be null to use server defaults. Probably only * the uid, gid and permissions * (remember the server may apply a umask) entries of the {@link SFTPv3FileHandle} * structure make sense. You need only to set those fields where you want * to override the server's defaults. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle createFile(String fileName, SFTPv3FileAttributes attr) throws IOException { return openFile(fileName, SSH_FXF_CREAT | SSH_FXF_READ | SSH_FXF_WRITE, attr); } /** * Create a file (truncate it if it already exists) and open it for writing. * Same as {@link #createFileTruncate(String, SFTPv3FileAttributes) createFileTruncate(fileName, null)}. * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle createFileTruncate(String fileName) throws IOException { return createFileTruncate(fileName, null); } /** * reate a file (truncate it if it already exists) and open it for writing. * You can specify the default attributes of the file (the server may or may * not respect your wishes). * * @param fileName See the {@link SFTPv3Client comment} for the class for more details. * @param attr may be null to use server defaults. Probably only * the uid, gid and permissions * (remember the server may apply a umask) entries of the {@link SFTPv3FileHandle} * structure make sense. You need only to set those fields where you want * to override the server's defaults. * @return a SFTPv3FileHandle handle * @throws IOException */ public SFTPv3FileHandle createFileTruncate(String fileName, SFTPv3FileAttributes attr) throws IOException { return openFile(fileName, SSH_FXF_CREAT | SSH_FXF_TRUNC | SSH_FXF_WRITE, attr); } private byte[] createAttrs(SFTPv3FileAttributes attr) { TypesWriter tw = new TypesWriter(); int attrFlags = 0; if (attr == null) { tw.writeUINT32(0); } else { if (attr.size != null) { attrFlags = attrFlags | AttribFlags.SSH_FILEXFER_ATTR_SIZE; } if ((attr.uid != null) && (attr.gid != null)) { attrFlags = attrFlags | AttribFlags.SSH_FILEXFER_ATTR_V3_UIDGID; } if (attr.permissions != null) { attrFlags = attrFlags | AttribFlags.SSH_FILEXFER_ATTR_PERMISSIONS; } if ((attr.atime != null) && (attr.mtime != null)) { attrFlags = attrFlags | AttribFlags.SSH_FILEXFER_ATTR_V3_ACMODTIME; } tw.writeUINT32(attrFlags); if (attr.size != null) { tw.writeUINT64(attr.size); } if ((attr.uid != null) && (attr.gid != null)) { tw.writeUINT32(attr.uid); tw.writeUINT32(attr.gid); } if (attr.permissions != null) { tw.writeUINT32(attr.permissions); } if ((attr.atime != null) && (attr.mtime != null)) { tw.writeUINT32(attr.atime); tw.writeUINT32(attr.mtime); } } return tw.getBytes(); } public SFTPv3FileHandle openFile(String fileName, int flags, SFTPv3FileAttributes attr) throws IOException { int req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(fileName, charsetName); tw.writeUINT32(flags); tw.writeBytes(createAttrs(attr)); log.debug("Sending SSH_FXP_OPEN..."); sendMessage(Packet.SSH_FXP_OPEN, req_id, tw.getBytes()); byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); int rep_id = tr.readUINT32(); if (rep_id != req_id) { throw new RequestMismatchException(); } if (t == Packet.SSH_FXP_HANDLE) { log.debug("Got SSH_FXP_HANDLE."); return new SFTPv3FileHandle(this, tr.readByteString()); } if (t != Packet.SSH_FXP_STATUS) { throw new PacketTypeException(t); } int errorCode = tr.readUINT32(); String errorMessage = tr.readString(); listener.read(errorMessage); throw new SFTPException(errorMessage, errorCode); } /** * A read is divided into multiple requests sent sequentially before * reading any status from the server */ private static class OutstandingReadRequest { int req_id; /** * Read offset to request on server starting at the file offset for the first request. */ long serverOffset; /** * Length of requested data */ int len; /** * Offset in destination buffer */ int dstOffset; /** * Temporary buffer */ byte[] buffer; } private void sendReadRequest(int id, SFTPv3FileHandle handle, long offset, int len) throws IOException { TypesWriter tw = new TypesWriter(); tw.writeString(handle.fileHandle, 0, handle.fileHandle.length); tw.writeUINT64(offset); tw.writeUINT32(len); log.debug("Sending SSH_FXP_READ (" + id + ") " + offset + "/" + len); sendMessage(Packet.SSH_FXP_READ, id, tw.getBytes()); } /** * Parallel read requests maximum size. */ private static final int DEFAULT_MAX_PARALLELISM = 64; /** * Parallel read requests. */ private int parallelism = DEFAULT_MAX_PARALLELISM; /** * @param parallelism */ public void setRequestParallelism(int parallelism) { this.parallelism = Math.min(parallelism, DEFAULT_MAX_PARALLELISM); } /** * Mapping request ID to request. */ private Map pendingReadQueue = new HashMap(); /** * Read bytes from a file in a parallel fashion. As many bytes as you want will be read. *

*

    *
  • The server will read as many bytes as it can from the file (up to len), * and return them.
  • *
  • If EOF is encountered before reading any data, -1 is returned. *
  • If an error occurs, an exception is thrown
  • . *
  • For normal disk files, it is guaranteed that the server will return the specified * number of bytes, or up to end of file. For, e.g., device files this may return * fewer bytes than requested.
  • *
* * @param handle a SFTPv3FileHandle handle * @param fileOffset offset (in bytes) in the file * @param dst the destination byte array * @param dstoff offset in the destination byte array * @param len how many bytes to read, 0 < len * @return the number of bytes that could be read, may be less than requested if * the end of the file is reached, -1 is returned in case of EOF * @throws IOException */ public int read(SFTPv3FileHandle handle, long fileOffset, byte[] dst, int dstoff, int len) throws IOException { boolean errorOccured = false; checkHandleValidAndOpen(handle); int remaining = len * parallelism; //int clientOffset = dstoff; long serverOffset = fileOffset; for (OutstandingReadRequest r : pendingReadQueue.values()) { // Server offset should take pending requests into account. serverOffset += r.len; } while (true) { // Stop if there was an error and no outstanding request if ((pendingReadQueue.size() == 0) && errorOccured) { break; } // Send as many requests as we are allowed to while (pendingReadQueue.size() < parallelism) { if (errorOccured) { break; } // Send the next read request OutstandingReadRequest req = new OutstandingReadRequest(); req.req_id = generateNextRequestID(); req.serverOffset = serverOffset; req.len = (remaining > len) ? len : remaining; req.buffer = dst; req.dstOffset = dstoff; serverOffset += req.len; //clientOffset += req.len; remaining -= req.len; sendReadRequest(req.req_id, handle, req.serverOffset, req.len); pendingReadQueue.put(req.req_id, req); } if (pendingReadQueue.size() == 0) { break; } // Receive a single answer byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); // Search the pending queue OutstandingReadRequest req = pendingReadQueue.remove(tr.readUINT32()); if (null == req) { throw new RequestMismatchException(); } // Evaluate the answer if (t == Packet.SSH_FXP_STATUS) { /* In any case, stop sending more packets */ int code = tr.readUINT32(); String msg = tr.readString(); listener.read(msg); if (log.isDebugEnabled()) { String[] desc = ErrorCodes.getDescription(code); log.debug("Got SSH_FXP_STATUS (" + req.req_id + ") (" + ((desc != null) ? desc[0] : "UNKNOWN") + ")"); } // Flag to read all pending requests but don't send any more. errorOccured = true; if (pendingReadQueue.isEmpty()) { if (ErrorCodes.SSH_FX_EOF == code) { return -1; } throw new SFTPException(msg, code); } } else if (t == Packet.SSH_FXP_DATA) { // OK, collect data int readLen = tr.readUINT32(); if ((readLen < 0) || (readLen > req.len)) { throw new IOException("The server sent an invalid length field in a SSH_FXP_DATA packet."); } if (log.isDebugEnabled()) { log.debug("Got SSH_FXP_DATA (" + req.req_id + ") " + req.serverOffset + "/" + readLen + " (requested: " + req.len + ")"); } // Read bytes into buffer tr.readBytes(req.buffer, req.dstOffset, readLen); if (readLen < req.len) { /* Send this request packet again to request the remaing data in this slot. */ req.req_id = generateNextRequestID(); req.serverOffset += readLen; req.len -= readLen; log.debug("Requesting again: " + req.serverOffset + "/" + req.len); sendReadRequest(req.req_id, handle, req.serverOffset, req.len); pendingReadQueue.put(req.req_id, req); } return readLen; } else { throw new PacketTypeException(t); } } // Should never reach here. throw new SFTPException("No EOF reached", -1); } /** * A read is divided into multiple requests sent sequentially before * reading any status from the server */ private static class OutstandingStatusRequest { int req_id; } /** * Mapping request ID to request. */ private Map pendingStatusQueue = new HashMap(); /** * Write bytes to a file. If len > 32768, then the write operation will * be split into multiple writes. * * @param handle a SFTPv3FileHandle handle. * @param fileOffset offset (in bytes) in the file. * @param src the source byte array. * @param srcoff offset in the source byte array. * @param len how many bytes to write. * @throws IOException */ public void write(SFTPv3FileHandle handle, long fileOffset, byte[] src, int srcoff, int len) throws IOException { checkHandleValidAndOpen(handle); while (len > 0) { int writeRequestLen = len; if (writeRequestLen > 32768) { writeRequestLen = 32768; } // Send the next write request OutstandingStatusRequest req = new OutstandingStatusRequest(); req.req_id = generateNextRequestID(); TypesWriter tw = new TypesWriter(); tw.writeString(handle.fileHandle, 0, handle.fileHandle.length); tw.writeUINT64(fileOffset); tw.writeString(src, srcoff, writeRequestLen); log.debug("Sending SSH_FXP_WRITE..."); sendMessage(Packet.SSH_FXP_WRITE, req.req_id, tw.getBytes()); pendingStatusQueue.put(req.req_id, req); // Only read next status if parallelism reached while (pendingStatusQueue.size() >= parallelism) { this.readStatus(); } fileOffset += writeRequestLen; srcoff += writeRequestLen; len -= writeRequestLen; } } private void readStatus() throws IOException { byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); // Search the pending queue OutstandingStatusRequest status = pendingStatusQueue.remove(tr.readUINT32()); if (null == status) { throw new RequestMismatchException(); } // Evaluate the answer if (t == Packet.SSH_FXP_STATUS) { // In any case, stop sending more packets int code = tr.readUINT32(); if (log.isDebugEnabled()) { String[] desc = ErrorCodes.getDescription(code); log.debug("Got SSH_FXP_STATUS (" + status.req_id + ") (" + ((desc != null) ? desc[0] : "UNKNOWN") + ")"); } if (code == ErrorCodes.SSH_FX_OK) { return; } String msg = tr.readString(); listener.read(msg); throw new SFTPException(msg, code); } throw new PacketTypeException(t); } private void readPendingReadStatus() throws IOException { byte[] resp = receiveMessage(34000); TypesReader tr = new TypesReader(resp); int t = tr.readByte(); listener.read(Packet.forName(t)); // Search the pending queue OutstandingReadRequest status = pendingReadQueue.remove(tr.readUINT32()); if (null == status) { throw new RequestMismatchException(); } // Evaluate the answer if (t == Packet.SSH_FXP_STATUS) { // In any case, stop sending more packets int code = tr.readUINT32(); if (log.isDebugEnabled()) { String[] desc = ErrorCodes.getDescription(code); log.debug("Got SSH_FXP_STATUS (" + status.req_id + ") (" + ((desc != null) ? desc[0] : "UNKNOWN") + ")"); } if (code == ErrorCodes.SSH_FX_OK) { return; } if (code == ErrorCodes.SSH_FX_EOF) { return; } String msg = tr.readString(); listener.read(msg); throw new SFTPException(msg, code); } throw new PacketTypeException(t); } /** * Close a file. * * @param handle a SFTPv3FileHandle handle * @throws IOException */ public void closeFile(SFTPv3FileHandle handle) throws IOException { try { while (!pendingReadQueue.isEmpty()) { this.readPendingReadStatus(); } while (!pendingStatusQueue.isEmpty()) { this.readStatus(); } if (!handle.isClosed) { closeHandle(handle.fileHandle); } } finally { handle.isClosed = true; } } }




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