2 import os, tempfile, heapq, binascii, traceback, array, stat, struct
3 from stat import S_IFREG, S_IFDIR
4 from time import time, strftime, localtime
6 from zope.interface import implements
7 from twisted.python import components
8 from twisted.application import service, strports
9 from twisted.conch.ssh import factory, keys, session
10 from twisted.conch.ssh.filetransfer import FileTransferServer, SFTPError, \
11 FX_NO_SUCH_FILE, FX_OP_UNSUPPORTED, FX_PERMISSION_DENIED, FX_EOF, \
12 FX_BAD_MESSAGE, FX_FAILURE, FX_OK
13 from twisted.conch.ssh.filetransfer import FXF_READ, FXF_WRITE, FXF_APPEND, \
14 FXF_CREAT, FXF_TRUNC, FXF_EXCL
15 from twisted.conch.interfaces import ISFTPServer, ISFTPFile, IConchUser, ISession
16 from twisted.conch.avatar import ConchUser
17 from twisted.conch.openssh_compat import primes
18 from twisted.cred import portal
19 from twisted.internet.error import ProcessDone, ProcessTerminated
20 from twisted.python.failure import Failure
21 from twisted.internet.interfaces import ITransport
23 from twisted.internet import defer
24 from twisted.internet.interfaces import IFinishableConsumer
25 from foolscap.api import eventually
26 from allmydata.util import deferredutil
28 from allmydata.util.consumer import download_to_data
29 from allmydata.interfaces import IFileNode, IDirectoryNode, ExistingChildError, \
30 NoSuchChildError, ChildOfWrongTypeError
31 from allmydata.mutable.common import NotWriteableError
32 from allmydata.immutable.upload import FileHandle
34 from pycryptopp.cipher.aes import AES
37 use_foolscap_logging = True
39 from allmydata.util.log import NOISY, OPERATIONAL, WEIRD, \
40 msg as _msg, err as _err, PrefixingLogMixin as _PrefixingLogMixin
42 if use_foolscap_logging:
43 (logmsg, logerr, PrefixingLogMixin) = (_msg, _err, _PrefixingLogMixin)
44 else: # pragma: no cover
45 def logmsg(s, level=None):
47 def logerr(s, level=None):
49 class PrefixingLogMixin:
50 def __init__(self, facility=None, prefix=''):
52 def log(self, s, level=None):
53 print "%r %s" % (self.prefix, s)
56 def eventually_callback(d):
57 return lambda res: eventually(d.callback, res)
59 def eventually_errback(d):
60 return lambda err: eventually(d.errback, err)
64 if isinstance(x, unicode):
65 return x.encode('utf-8')
66 if isinstance(x, str):
72 """SFTP times are unsigned 32-bit integers representing UTC seconds
73 (ignoring leap seconds) since the Unix epoch, January 1 1970 00:00 UTC.
74 A Tahoe time is the corresponding float."""
75 return long(t) & 0xFFFFFFFFL
78 def _convert_error(res, request):
79 if not isinstance(res, Failure):
81 if isinstance(res, str): logged_res = "<data of length %r>" % (len(res),)
82 logmsg("SUCCESS %r %r" % (request, logged_res,), level=OPERATIONAL)
86 logmsg("RAISE %r %r" % (request, err.value), level=OPERATIONAL)
88 if noisy: logmsg(traceback.format_exc(err.value), level=NOISY)
89 except: # pragma: no cover
92 # The message argument to SFTPError must not reveal information that
93 # might compromise anonymity.
95 if err.check(SFTPError):
96 # original raiser of SFTPError has responsibility to ensure anonymity
98 if err.check(NoSuchChildError):
99 childname = _utf8(err.value.args[0])
100 raise SFTPError(FX_NO_SUCH_FILE, childname)
101 if err.check(NotWriteableError) or err.check(ChildOfWrongTypeError):
102 msg = _utf8(err.value.args[0])
103 raise SFTPError(FX_PERMISSION_DENIED, msg)
104 if err.check(ExistingChildError):
105 # Versions of SFTP after v3 (which is what twisted.conch implements)
106 # define a specific error code for this case: FX_FILE_ALREADY_EXISTS.
107 # However v3 doesn't; instead, other servers such as sshd return
108 # FX_FAILURE. The gvfs SFTP backend, for example, depends on this
109 # to translate the error to the equivalent of POSIX EEXIST, which is
110 # necessary for some picky programs (such as gedit).
111 msg = _utf8(err.value.args[0])
112 raise SFTPError(FX_FAILURE, msg)
113 if err.check(NotImplementedError):
114 raise SFTPError(FX_OP_UNSUPPORTED, _utf8(err.value))
115 if err.check(EOFError):
116 raise SFTPError(FX_EOF, "end of file reached")
117 if err.check(defer.FirstError):
118 _convert_error(err.value.subFailure, request)
120 # We assume that the error message is not anonymity-sensitive.
121 raise SFTPError(FX_FAILURE, _utf8(err.value))
124 def _repr_flags(flags):
125 return "|".join([f for f in
126 [(flags & FXF_READ) and "FXF_READ" or None,
127 (flags & FXF_WRITE) and "FXF_WRITE" or None,
128 (flags & FXF_APPEND) and "FXF_APPEND" or None,
129 (flags & FXF_CREAT) and "FXF_CREAT" or None,
130 (flags & FXF_TRUNC) and "FXF_TRUNC" or None,
131 (flags & FXF_EXCL) and "FXF_EXCL" or None,
136 def _lsLine(name, attrs):
139 st_mtime = attrs.get("mtime", 0)
140 st_mode = attrs["permissions"]
141 # TODO: check that clients are okay with this being a "?".
142 # (They should be because the longname is intended for human
144 st_size = attrs.get("size", "?")
145 # We don't know how many links there really are to this object.
148 # Based on <http://twistedmatrix.com/trac/browser/trunk/twisted/conch/ls.py?rev=25412>.
149 # We can't call the version in Twisted because we might have a version earlier than
150 # <http://twistedmatrix.com/trac/changeset/25412> (released in Twisted 8.2).
153 perms = array.array('c', '-'*10)
154 ft = stat.S_IFMT(mode)
155 if stat.S_ISDIR(ft): perms[0] = 'd'
156 elif stat.S_ISREG(ft): perms[0] = '-'
159 if mode&stat.S_IRUSR: perms[1] = 'r'
160 if mode&stat.S_IWUSR: perms[2] = 'w'
161 if mode&stat.S_IXUSR: perms[3] = 'x'
163 if mode&stat.S_IRGRP: perms[4] = 'r'
164 if mode&stat.S_IWGRP: perms[5] = 'w'
165 if mode&stat.S_IXGRP: perms[6] = 'x'
167 if mode&stat.S_IROTH: perms[7] = 'r'
168 if mode&stat.S_IWOTH: perms[8] = 'w'
169 if mode&stat.S_IXOTH: perms[9] = 'x'
170 # suid/sgid never set
173 l += str(st_nlink).rjust(5) + ' '
184 if st_mtime + sixmo < now or st_mtime > now + day:
185 # mtime is more than 6 months ago, or more than one day in the future
186 l += strftime("%b %d %Y ", localtime(st_mtime))
188 l += strftime("%b %d %H:%M ", localtime(st_mtime))
193 def _is_readonly(parent_readonly, child):
194 """Whether child should be listed as having read-only permissions in parent."""
196 if child.is_unknown():
198 elif child.is_mutable():
199 return child.is_readonly()
201 return parent_readonly
204 def _populate_attrs(childnode, metadata, size=None):
207 # The permissions must have the S_IFDIR (040000) or S_IFREG (0100000)
208 # bits, otherwise the client may refuse to open a directory.
209 # Also, sshfs run as a non-root user requires files and directories
210 # to be world-readable/writeable.
212 # Directories and unknown nodes have no size, and SFTP doesn't
213 # require us to make one up.
215 # childnode might be None, meaning that the file doesn't exist yet,
216 # but we're going to write it later.
218 if childnode and childnode.is_unknown():
220 elif childnode and IDirectoryNode.providedBy(childnode):
221 perms = S_IFDIR | 0777
223 # For files, omit the size if we don't immediately know it.
224 if childnode and size is None:
225 size = childnode.get_size()
227 assert isinstance(size, (int, long)) and not isinstance(size, bool), repr(size)
229 perms = S_IFREG | 0666
232 assert 'readonly' in metadata, metadata
233 if metadata['readonly']:
234 perms &= S_IFDIR | S_IFREG | 0555 # clear 'w' bits
236 # see webapi.txt for what these times mean
237 if 'linkmotime' in metadata.get('tahoe', {}):
238 attrs['mtime'] = _to_sftp_time(metadata['tahoe']['linkmotime'])
239 elif 'mtime' in metadata:
240 # We would prefer to omit atime, but SFTP version 3 can only
241 # accept mtime if atime is also set.
242 attrs['mtime'] = _to_sftp_time(metadata['mtime'])
243 attrs['atime'] = attrs['mtime']
245 if 'linkcrtime' in metadata.get('tahoe', {}):
246 attrs['createtime'] = _to_sftp_time(metadata['tahoe']['linkcrtime'])
248 if 'ctime' in metadata:
249 attrs['ctime'] = _to_sftp_time(metadata['ctime'])
251 attrs['permissions'] = perms
253 # twisted.conch.ssh.filetransfer only implements SFTP version 3,
254 # which doesn't include SSH_FILEXFER_ATTR_FLAGS.
259 class EncryptedTemporaryFile(PrefixingLogMixin):
260 # not implemented: next, readline, readlines, xreadlines, writelines
263 PrefixingLogMixin.__init__(self, facility="tahoe.sftp")
264 self.file = tempfile.TemporaryFile()
265 self.key = os.urandom(16) # AES-128
267 def _crypt(self, offset, data):
268 # TODO: use random-access AES (pycryptopp ticket #18)
269 offset_big = offset // 16
270 offset_small = offset % 16
271 iv = binascii.unhexlify("%032x" % offset_big)
272 cipher = AES(self.key, iv=iv)
273 cipher.process("\x00"*offset_small)
274 return cipher.process(data)
282 def seek(self, offset, whence=os.SEEK_SET):
283 if noisy: self.log(".seek(%r, %r)" % (offset, whence), level=NOISY)
284 self.file.seek(offset, whence)
287 offset = self.file.tell()
288 if noisy: self.log(".tell() = %r" % (offset,), level=NOISY)
291 def read(self, size=-1):
292 if noisy: self.log(".read(%r)" % (size,), level=NOISY)
293 index = self.file.tell()
294 ciphertext = self.file.read(size)
295 plaintext = self._crypt(index, ciphertext)
298 def write(self, plaintext):
299 if noisy: self.log(".write(<data of length %r>)" % (len(plaintext),), level=NOISY)
300 index = self.file.tell()
301 ciphertext = self._crypt(index, plaintext)
302 self.file.write(ciphertext)
304 def truncate(self, newsize):
305 if noisy: self.log(".truncate(%r)" % (newsize,), level=NOISY)
306 self.file.truncate(newsize)
309 class OverwriteableFileConsumer(PrefixingLogMixin):
310 implements(IFinishableConsumer)
311 """I act both as a consumer for the download of the original file contents, and as a
312 wrapper for a temporary file that records the downloaded data and any overwrites.
313 I use a priority queue to keep track of which regions of the file have been overwritten
314 but not yet downloaded, so that the download does not clobber overwritten data.
315 I use another priority queue to record milestones at which to make callbacks
316 indicating that a given number of bytes have been downloaded.
318 The temporary file reflects the contents of the file that I represent, except that:
319 - regions that have neither been downloaded nor overwritten, if present,
321 - the temporary file may be shorter than the represented file (it is never longer).
322 The latter's current size is stored in self.current_size.
324 This abstraction is mostly independent of SFTP. Consider moving it, if it is found
325 useful for other frontends."""
327 def __init__(self, download_size, tempfile_maker):
328 PrefixingLogMixin.__init__(self, facility="tahoe.sftp")
329 if noisy: self.log(".__init__(%r, %r)" % (download_size, tempfile_maker), level=NOISY)
330 self.download_size = download_size
331 self.current_size = download_size
332 self.f = tempfile_maker()
334 self.milestones = [] # empty heap of (offset, d)
335 self.overwrites = [] # empty heap of (start, end)
336 self.is_closed = False
337 self.done = self.when_reached(download_size) # adds a milestone
339 def _signal_done(ign):
340 if noisy: self.log("DONE", level=NOISY)
342 self.done.addCallback(_signal_done)
348 def get_current_size(self):
349 return self.current_size
351 def set_current_size(self, size):
352 if noisy: self.log(".set_current_size(%r), current_size = %r, downloaded = %r" %
353 (size, self.current_size, self.downloaded), level=NOISY)
354 if size < self.current_size or size < self.downloaded:
355 self.f.truncate(size)
356 if size > self.current_size:
357 self.overwrite(self.current_size, "\x00" * (size - self.current_size))
358 self.current_size = size
360 # invariant: self.download_size <= self.current_size
361 if size < self.download_size:
362 self.download_size = size
363 if self.downloaded >= self.download_size:
366 def registerProducer(self, p, streaming):
367 if noisy: self.log(".registerProducer(%r, streaming=%r)" % (p, streaming), level=NOISY)
370 # call resumeProducing once to start things off
379 def write(self, data):
380 if noisy: self.log(".write(<data of length %r>)" % (len(data),), level=NOISY)
384 if self.downloaded >= self.download_size:
387 next_downloaded = self.downloaded + len(data)
388 if next_downloaded > self.download_size:
389 data = data[:(self.download_size - self.downloaded)]
391 while len(self.overwrites) > 0:
392 (start, end) = self.overwrites[0]
393 if start >= next_downloaded:
394 # This and all remaining overwrites are after the data we just downloaded.
396 if start > self.downloaded:
397 # The data we just downloaded has been partially overwritten.
398 # Write the prefix of it that precedes the overwritten region.
399 self.f.seek(self.downloaded)
400 self.f.write(data[:(start - self.downloaded)])
402 # This merges consecutive overwrites if possible, which allows us to detect the
403 # case where the download can be stopped early because the remaining region
404 # to download has already been fully overwritten.
405 heapq.heappop(self.overwrites)
406 while len(self.overwrites) > 0:
407 (start1, end1) = self.overwrites[0]
411 heapq.heappop(self.overwrites)
413 if end >= next_downloaded:
414 # This overwrite extends past the downloaded data, so there is no
415 # more data to consider on this call.
416 heapq.heappush(self.overwrites, (next_downloaded, end))
417 self._update_downloaded(next_downloaded)
419 elif end >= self.downloaded:
420 data = data[(end - self.downloaded):]
421 self._update_downloaded(end)
423 self.f.seek(self.downloaded)
425 self._update_downloaded(next_downloaded)
427 def _update_downloaded(self, new_downloaded):
428 self.downloaded = new_downloaded
429 milestone = new_downloaded
430 if len(self.overwrites) > 0:
431 (start, end) = self.overwrites[0]
432 if start <= new_downloaded and end > milestone:
435 while len(self.milestones) > 0:
436 (next, d) = self.milestones[0]
439 if noisy: self.log("MILESTONE %r %r" % (next, d), level=NOISY)
440 heapq.heappop(self.milestones)
441 eventually_callback(d)(None)
443 if milestone >= self.download_size:
446 def overwrite(self, offset, data):
447 if noisy: self.log(".overwrite(%r, <data of length %r>)" % (offset, len(data)), level=NOISY)
448 if offset > self.current_size:
449 # Normally writing at an offset beyond the current end-of-file
450 # would leave a hole that appears filled with zeroes. However, an
451 # EncryptedTemporaryFile doesn't behave like that (if there is a
452 # hole in the file on disk, the zeroes that are read back will be
453 # XORed with the keystream). So we must explicitly write zeroes in
454 # the gap between the current EOF and the offset.
456 self.f.seek(self.current_size)
457 self.f.write("\x00" * (offset - self.current_size))
458 start = self.current_size
464 end = offset + len(data)
465 self.current_size = max(self.current_size, end)
466 if end > self.downloaded:
467 heapq.heappush(self.overwrites, (start, end))
469 def read(self, offset, length):
470 """When the data has been read, callback the Deferred that we return with this data.
471 Otherwise errback the Deferred that we return.
472 The caller must perform no more overwrites until the Deferred has fired."""
474 if noisy: self.log(".read(%r, %r), current_size = %r" % (offset, length, self.current_size), level=NOISY)
475 if offset >= self.current_size:
476 def _eof(): raise EOFError("read past end of file")
477 return defer.execute(_eof)
479 if offset + length > self.current_size:
480 length = self.current_size - offset
481 if noisy: self.log("truncating read to %r bytes" % (length,), level=NOISY)
483 needed = min(offset + length, self.download_size)
484 d = self.when_reached(needed)
486 # It is not necessarily the case that self.downloaded >= needed, because
487 # the file might have been truncated (thus truncating the download) and
490 assert self.current_size >= offset + length, (self.current_size, offset, length)
491 if noisy: self.log("self.f = %r" % (self.f,), level=NOISY)
493 return self.f.read(length)
494 d.addCallback(_reached)
497 def when_reached(self, index):
498 if noisy: self.log(".when_reached(%r)" % (index,), level=NOISY)
499 if index <= self.downloaded: # already reached
500 if noisy: self.log("already reached %r" % (index,), level=NOISY)
501 return defer.succeed(None)
504 if noisy: self.log("reached %r" % (index,), level=NOISY)
506 d.addCallback(_reached)
507 heapq.heappush(self.milestones, (index, d))
514 while len(self.milestones) > 0:
515 (next, d) = self.milestones[0]
516 if noisy: self.log("MILESTONE FINISH %r %r" % (next, d), level=NOISY)
517 heapq.heappop(self.milestones)
518 # The callback means that the milestone has been reached if
519 # it is ever going to be. Note that the file may have been
520 # truncated to before the milestone.
521 eventually_callback(d)(None)
523 # FIXME: causes spurious failures
524 #self.unregisterProducer()
527 self.is_closed = True
531 except EnvironmentError as e:
532 self.log("suppressed %r from close of temporary file %r" % (e, self.f), level=WEIRD)
534 def unregisterProducer(self):
536 self.producer.stopProducing()
540 SIZE_THRESHOLD = 1000
543 class ShortReadOnlySFTPFile(PrefixingLogMixin):
544 implements(ISFTPFile)
545 """I represent a file handle to a particular file on an SFTP connection.
546 I am used only for short immutable files opened in read-only mode.
547 The file contents are downloaded to memory when I am created."""
549 def __init__(self, userpath, filenode, metadata):
550 PrefixingLogMixin.__init__(self, facility="tahoe.sftp", prefix=userpath)
551 if noisy: self.log(".__init__(%r, %r, %r)" % (userpath, filenode, metadata), level=NOISY)
553 assert IFileNode.providedBy(filenode), filenode
554 self.filenode = filenode
555 self.metadata = metadata
556 self.async = download_to_data(filenode)
559 def readChunk(self, offset, length):
560 request = ".readChunk(%r, %r)" % (offset, length)
561 self.log(request, level=OPERATIONAL)
564 def _closed(): raise SFTPError(FX_BAD_MESSAGE, "cannot read from a closed file handle")
565 return defer.execute(_closed)
569 if noisy: self.log("_read(<data of length %r>) in readChunk(%r, %r)" % (len(data), offset, length), level=NOISY)
571 # "In response to this request, the server will read as many bytes as it
572 # can from the file (up to 'len'), and return them in a SSH_FXP_DATA
573 # message. If an error occurs or EOF is encountered before reading any
574 # data, the server will respond with SSH_FXP_STATUS. For normal disk
575 # files, it is guaranteed that this will read the specified number of
576 # bytes, or up to end of file."
578 # i.e. we respond with an EOF error iff offset is already at EOF.
580 if offset >= len(data):
581 eventually_errback(d)(SFTPError(FX_EOF, "read at or past end of file"))
583 eventually_callback(d)(data[offset:min(offset+length, len(data))])
585 self.async.addCallbacks(_read, eventually_errback(d))
586 d.addBoth(_convert_error, request)
589 def writeChunk(self, offset, data):
590 self.log(".writeChunk(%r, <data of length %r>) denied" % (offset, len(data)), level=OPERATIONAL)
592 def _denied(): raise SFTPError(FX_PERMISSION_DENIED, "file handle was not opened for writing")
593 return defer.execute(_denied)
596 self.log(".close()", level=OPERATIONAL)
599 return defer.succeed(None)
602 request = ".getAttrs()"
603 self.log(request, level=OPERATIONAL)
606 def _closed(): raise SFTPError(FX_BAD_MESSAGE, "cannot get attributes for a closed file handle")
607 return defer.execute(_closed)
609 d = defer.execute(_populate_attrs, self.filenode, self.metadata)
610 d.addBoth(_convert_error, request)
613 def setAttrs(self, attrs):
614 self.log(".setAttrs(%r) denied" % (attrs,), level=OPERATIONAL)
615 def _denied(): raise SFTPError(FX_PERMISSION_DENIED, "file handle was not opened for writing")
616 return defer.execute(_denied)
619 class GeneralSFTPFile(PrefixingLogMixin):
620 implements(ISFTPFile)
621 """I represent a file handle to a particular file on an SFTP connection.
622 I wrap an instance of OverwriteableFileConsumer, which is responsible for
623 storing the file contents. In order to allow write requests to be satisfied
624 immediately, there is effectively a FIFO queue between requests made to this
625 file handle, and requests to my OverwriteableFileConsumer. This queue is
626 implemented by the callback chain of self.async.
628 When first constructed, I am in an 'unopened' state that causes most
629 operations to be delayed until 'open' is called."""
631 def __init__(self, userpath, flags, close_notify, convergence):
632 PrefixingLogMixin.__init__(self, facility="tahoe.sftp", prefix=userpath)
633 if noisy: self.log(".__init__(%r, %r = %r, %r, <convergence censored>)" %
634 (userpath, flags, _repr_flags(flags), close_notify), level=NOISY)
636 self.userpath = userpath
638 self.close_notify = close_notify
639 self.convergence = convergence
640 self.async = defer.Deferred()
641 # Creating or truncating the file is a change, but if FXF_EXCL is set, a zero-length file has already been created.
642 self.has_changed = (flags & (FXF_CREAT | FXF_TRUNC)) and not (flags & FXF_EXCL)
644 self.abandoned = False
646 self.childname = None
650 # self.consumer should only be relied on in callbacks for self.async, since it might
651 # not be set before then.
654 def open(self, parent=None, childname=None, filenode=None, metadata=None):
655 self.log(".open(parent=%r, childname=%r, filenode=%r, metadata=%r)" %
656 (parent, childname, filenode, metadata), level=OPERATIONAL)
658 # If the file has been renamed, the new (parent, childname) takes precedence.
659 if self.parent is None:
661 if self.childname is None:
662 self.childname = childname
663 self.filenode = filenode
664 self.metadata = metadata
667 tempfile_maker = EncryptedTemporaryFile
669 if (self.flags & FXF_TRUNC) or not filenode:
670 # We're either truncating or creating the file, so we don't need the old contents.
671 self.consumer = OverwriteableFileConsumer(0, tempfile_maker)
672 self.consumer.finish()
674 assert IFileNode.providedBy(filenode), filenode
676 # TODO: use download interface described in #993 when implemented.
677 if filenode.is_mutable():
678 self.async.addCallback(lambda ign: filenode.download_best_version())
679 def _downloaded(data):
680 self.consumer = OverwriteableFileConsumer(len(data), tempfile_maker)
681 self.consumer.write(data)
682 self.consumer.finish()
684 self.async.addCallback(_downloaded)
686 download_size = filenode.get_size()
687 assert download_size is not None, "download_size is None"
688 self.consumer = OverwriteableFileConsumer(download_size, tempfile_maker)
690 if noisy: self.log("_read immutable", level=NOISY)
691 filenode.read(self.consumer, 0, None)
692 self.async.addCallback(_read)
694 eventually_callback(self.async)(None)
696 if noisy: self.log("open done", level=NOISY)
699 def rename(self, new_userpath, new_parent, new_childname):
700 self.log(".rename(%r, %r, %r)" % (new_userpath, new_parent, new_childname), level=OPERATIONAL)
702 self.userpath = new_userpath
703 self.parent = new_parent
704 self.childname = new_childname
707 self.log(".abandon()", level=OPERATIONAL)
709 self.abandoned = True
712 self.log(".sync()", level=OPERATIONAL)
715 self.async.addBoth(eventually_callback(d))
718 def readChunk(self, offset, length):
719 request = ".readChunk(%r, %r)" % (offset, length)
720 self.log(request, level=OPERATIONAL)
722 if not (self.flags & FXF_READ):
723 def _denied(): raise SFTPError(FX_PERMISSION_DENIED, "file handle was not opened for reading")
724 return defer.execute(_denied)
727 def _closed(): raise SFTPError(FX_BAD_MESSAGE, "cannot read from a closed file handle")
728 return defer.execute(_closed)
732 if noisy: self.log("_read in readChunk(%r, %r)" % (offset, length), level=NOISY)
733 d2 = self.consumer.read(offset, length)
734 d2.addCallbacks(eventually_callback(d), eventually_errback(d))
735 # It is correct to drop d2 here.
737 self.async.addCallbacks(_read, eventually_errback(d))
738 d.addBoth(_convert_error, request)
741 def writeChunk(self, offset, data):
742 self.log(".writeChunk(%r, <data of length %r>)" % (offset, len(data)), level=OPERATIONAL)
744 if not (self.flags & FXF_WRITE):
745 def _denied(): raise SFTPError(FX_PERMISSION_DENIED, "file handle was not opened for writing")
746 return defer.execute(_denied)
749 def _closed(): raise SFTPError(FX_BAD_MESSAGE, "cannot write to a closed file handle")
750 return defer.execute(_closed)
752 self.has_changed = True
754 # Note that we return without waiting for the write to occur. Reads and
755 # close wait for prior writes, and will fail if any prior operation failed.
756 # This is ok because SFTP makes no guarantee that the write completes
757 # before the request does. In fact it explicitly allows write errors to be
758 # delayed until close:
759 # "One should note that on some server platforms even a close can fail.
760 # This can happen e.g. if the server operating system caches writes,
761 # and an error occurs while flushing cached writes during the close."
764 if noisy: self.log("_write in .writeChunk(%r, <data of length %r>), current_size = %r" %
765 (offset, len(data), self.consumer.get_current_size()), level=NOISY)
766 # FXF_APPEND means that we should always write at the current end of file.
767 write_offset = offset
768 if self.flags & FXF_APPEND:
769 write_offset = self.consumer.get_current_size()
771 self.consumer.overwrite(write_offset, data)
772 if noisy: self.log("overwrite done", level=NOISY)
774 self.async.addCallback(_write)
775 # don't addErrback to self.async, just allow subsequent async ops to fail.
776 return defer.succeed(None)
780 self.log(request, level=OPERATIONAL)
783 return defer.succeed(None)
785 # This means that close has been called, not that the close has succeeded.
788 if not (self.flags & (FXF_WRITE | FXF_CREAT)):
789 def _readonly_close():
791 self.consumer.close()
792 return defer.execute(_readonly_close)
794 # We must capture the abandoned, parent, and childname variables synchronously
795 # at the close call. This is needed by the correctness arguments in the comments
796 # for _abandon_any_heisenfiles and _rename_heisenfiles.
797 abandoned = self.abandoned
799 childname = self.childname
802 d2 = defer.succeed(None)
803 if self.has_changed and not abandoned:
804 d2.addCallback(lambda ign: self.consumer.when_done())
805 if self.filenode and self.filenode.is_mutable():
806 self.log("update mutable file %r childname=%r" % (self.filenode, self.childname,), level=OPERATIONAL)
807 d2.addCallback(lambda ign: self.consumer.get_current_size())
808 d2.addCallback(lambda size: self.consumer.read(0, size))
809 d2.addCallback(lambda new_contents: self.filenode.overwrite(new_contents))
812 self.log("_add_file childname=%r" % (childname,), level=OPERATIONAL)
813 u = FileHandle(self.consumer.get_file(), self.convergence)
814 return parent.add_file(childname, u)
815 d2.addCallback(_add_file)
818 if noisy: self.log("_committed(%r)" % (res,), level=NOISY)
820 self.consumer.close()
822 # We must close_notify before re-firing self.async.
823 if self.close_notify:
824 self.close_notify(self.userpath, self.parent, self.childname, self)
826 d2.addBoth(_committed)
829 self.async.addCallback(_close)
832 self.async.addCallbacks(eventually_callback(d), eventually_errback(d))
833 d.addBoth(_convert_error, request)
837 request = ".getAttrs()"
838 self.log(request, level=OPERATIONAL)
841 def _closed(): raise SFTPError(FX_BAD_MESSAGE, "cannot get attributes for a closed file handle")
842 return defer.execute(_closed)
844 # Optimization for read-only handles, when we already know the metadata.
845 if not(self.flags & (FXF_WRITE | FXF_CREAT)) and self.metadata and self.filenode and not self.filenode.is_mutable():
846 return defer.succeed(_populate_attrs(self.filenode, self.metadata))
850 # self.filenode might be None, but that's ok.
851 attrs = _populate_attrs(self.filenode, self.metadata, size=self.consumer.get_current_size())
852 eventually_callback(d)(attrs)
854 self.async.addCallbacks(_get, eventually_errback(d))
855 d.addBoth(_convert_error, request)
858 def setAttrs(self, attrs):
859 request = ".setAttrs(attrs) %r" % (attrs,)
860 self.log(request, level=OPERATIONAL)
862 if not (self.flags & FXF_WRITE):
863 def _denied(): raise SFTPError(FX_PERMISSION_DENIED, "file handle was not opened for writing")
864 return defer.execute(_denied)
867 def _closed(): raise SFTPError(FX_BAD_MESSAGE, "cannot set attributes for a closed file handle")
868 return defer.execute(_closed)
870 if not "size" in attrs:
871 return defer.succeed(None)
874 if not isinstance(size, (int, long)) or size < 0:
875 def _bad(): raise SFTPError(FX_BAD_MESSAGE, "new size is not a valid nonnegative integer")
876 return defer.execute(_bad)
880 self.consumer.set_current_size(size)
881 eventually_callback(d)(None)
883 self.async.addCallbacks(_resize, eventually_errback(d))
884 d.addBoth(_convert_error, request)
889 def __init__(self, items):
899 def __init__(self, value):
903 # A "heisenfile" is a file that has been opened with write flags
904 # (FXF_WRITE and/or FXF_CREAT) and not yet close-notified.
905 # 'all_heisenfiles' maps from a direntry string to
906 # (list_of_GeneralSFTPFile, open_time_utc).
907 # A direntry string is parent_write_uri + "/" + childname_utf8 for
908 # an immutable file, or file_write_uri for a mutable file.
909 # Updates to this dict are single-threaded.
914 class SFTPUserHandler(ConchUser, PrefixingLogMixin):
915 implements(ISFTPServer)
916 def __init__(self, client, rootnode, username):
917 ConchUser.__init__(self)
918 PrefixingLogMixin.__init__(self, facility="tahoe.sftp", prefix=username)
919 if noisy: self.log(".__init__(%r, %r, %r)" % (client, rootnode, username), level=NOISY)
921 self.channelLookup["session"] = session.SSHSession
922 self.subsystemLookup["sftp"] = FileTransferServer
924 self._client = client
925 self._root = rootnode
926 self._username = username
927 self._convergence = client.convergence
929 # maps from UTF-8 paths for this user, to files written and still open
930 self._heisenfiles = {}
932 def gotVersion(self, otherVersion, extData):
933 self.log(".gotVersion(%r, %r)" % (otherVersion, extData), level=OPERATIONAL)
935 # advertise the same extensions as the OpenSSH SFTP server
936 # <http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL?rev=1.15>
937 return {'posix-rename@openssh.com': '1',
938 'statvfs@openssh.com': '2',
939 'fstatvfs@openssh.com': '2',
943 self.log(".logout()", level=OPERATIONAL)
945 for files in self._heisenfiles.itervalues():
949 def _add_heisenfiles_by_path(self, userpath, files):
950 if noisy: self.log("._add_heisenfiles_by_path(%r, %r)" % (userpath, files), level=NOISY)
952 if userpath in self._heisenfiles:
953 self._heisenfiles[userpath] += files
955 self._heisenfiles[userpath] = files
957 def _add_heisenfiles_by_direntry(self, direntry, files_to_add):
958 if noisy: self.log("._add_heisenfiles_by_direntry(%r, %r)" % (direntry, files_to_add), level=NOISY)
961 if direntry in all_heisenfiles:
962 (old_files, opentime) = all_heisenfiles[direntry]
963 all_heisenfiles[direntry] = (old_files + files_to_add, opentime)
965 all_heisenfiles[direntry] = (files_to_add, time())
967 def _abandon_any_heisenfiles(self, userpath, direntry):
968 if noisy: self.log("._abandon_any_heisenfiles(%r, %r)" % (userpath, direntry), level=NOISY)
970 # First we synchronously mark all heisenfiles matching the userpath or direntry
971 # as abandoned, and remove them from the two heisenfile dicts. Then we .sync()
972 # each file that we abandoned.
974 # For each file, the call to .abandon() occurs:
975 # * before the file is closed, in which case it will never be committed
976 # (uploaded+linked or published); or
977 # * after it is closed but before it has been close_notified, in which case the
978 # .sync() ensures that it has been committed (successfully or not) before we
981 # This avoids a race that might otherwise cause the file to be committed after
982 # the remove operation has completed.
984 # We return a Deferred that fires with True if any files were abandoned (this
985 # does not mean that they were not committed; it is used to determine whether
986 # a NoSuchChildError from the attempt to delete the file should be suppressed).
989 if direntry in all_heisenfiles:
990 (files, opentime) = all_heisenfiles[direntry]
991 del all_heisenfiles[direntry]
992 if userpath in self._heisenfiles:
993 files += self._heisenfiles[userpath]
994 del self._heisenfiles[userpath]
999 d = defer.succeed(None)
1001 d.addBoth(lambda ign: f.sync())
1003 d.addBoth(lambda ign: len(files) > 0)
1006 def _rename_heisenfiles(self, from_userpath, from_parent, from_childname,
1007 to_userpath, to_parent, to_childname, overwrite=True):
1008 if noisy: self.log("._rename_heisenfiles(%r, %r, %r, %r, %r, %r, overwrite=%r)" %
1009 (from_userpath, from_parent, from_childname,
1010 to_userpath, to_parent, to_childname, overwrite), level=NOISY)
1012 # First we synchronously rename all heisenfiles matching the userpath or direntry.
1013 # Then we .sync() each file that we renamed.
1015 # For each file, the call to .rename occurs:
1016 # * before the file is closed, in which case it will be committed at the
1018 # * after it is closed but before it has been close_notified, in which case the
1019 # .sync() ensures that it has been committed (successfully or not) before we
1022 # This avoids a race that might otherwise cause the file to be committed at the
1023 # old name after the rename operation has completed.
1025 # Note that if overwrite is False, the caller should already have checked
1026 # whether a real direntry exists at the destination. It is possible that another
1027 # direntry (heisen or real) comes to exist at the destination after that check,
1028 # but in that case it is correct for the rename to succeed (and for the commit
1029 # of the heisenfile at the destination to possibly clobber the other entry, since
1030 # that can happen anyway when we have concurrent write handles to the same direntry).
1032 # We return a Deferred that fires with True if any files were renamed (this
1033 # does not mean that they were not committed; it is used to determine whether
1034 # a NoSuchChildError from the rename attempt should be suppressed). If overwrite
1035 # is False and there were already heisenfiles at the destination userpath or
1036 # direntry, we return a Deferred that fails with SFTPError(FX_PERMISSION_DENIED).
1038 from_direntry = self._direntry_for(from_parent, from_childname)
1039 to_direntry = self._direntry_for(to_parent, to_childname)
1041 if not overwrite and (to_userpath in self._heisenfiles or to_direntry in all_heisenfiles):
1042 def _existing(): raise SFTPError(FX_PERMISSION_DENIED, "cannot rename to existing path " + to_userpath)
1043 return defer.execute(_existing)
1046 if from_direntry in all_heisenfiles:
1047 (from_files, opentime) = all_heisenfiles[from_direntry]
1048 del all_heisenfiles[from_direntry]
1049 if from_userpath in self._heisenfiles:
1050 from_files += self._heisenfiles[from_userpath]
1051 del self._heisenfiles[from_userpath]
1053 self._add_heisenfiles_by_direntry(to_direntry, from_files)
1054 self._add_heisenfiles_by_path(to_userpath, from_files)
1056 for f in from_files:
1057 f.rename(to_userpath, to_parent, to_childname)
1059 d = defer.succeed(None)
1060 for f in from_files:
1061 d.addBoth(lambda ign: f.sync())
1063 d.addBoth(lambda ign: len(from_files) > 0)
1066 def _sync_heisenfiles(self, userpath, direntry, ignore=None):
1067 if noisy: self.log("._sync_heisenfiles(%r, %r)" % (userpath, direntry), level=NOISY)
1070 if direntry in all_heisenfiles:
1071 (files, opentime) = all_heisenfiles[direntry]
1072 if userpath in self._heisenfiles:
1073 files += self._heisenfiles[userpath]
1075 d = defer.succeed(None)
1078 d.addCallback(lambda ign: f.sync())
1081 def _remove_heisenfile(self, userpath, parent, childname, file_to_remove):
1082 if noisy: self.log("._remove_file(%r, %r, %r, %r)" % (userpath, parent, childname, file_to_remove), level=NOISY)
1084 direntry = self._direntry_for(parent, childname)
1085 if direntry in all_heisenfiles:
1086 (all_old_files, opentime) = all_heisenfiles[direntry]
1087 all_new_files = [f for f in all_old_files if f is not file_to_remove]
1088 if len(all_new_files) > 0:
1089 all_heisenfiles[direntry] = (all_new_files, opentime)
1091 del all_heisenfiles[direntry]
1093 if userpath in self._heisenfiles:
1094 old_files = self._heisenfiles[userpath]
1095 new_files = [f for f in old_files if f is not file_to_remove]
1096 if len(new_files) > 0:
1097 self._heisenfiles[userpath] = new_files
1099 del self._heisenfiles[userpath]
1101 def _direntry_for(self, filenode_or_parent, childname=None):
1102 if filenode_or_parent:
1103 rw_uri = filenode_or_parent.get_write_uri()
1104 if rw_uri and childname:
1105 return rw_uri + "/" + childname.encode('utf-8')
1111 def _make_file(self, existing_file, userpath, flags, parent=None, childname=None, filenode=None, metadata=None):
1112 if noisy: self.log("._make_file(%r, %r, %r = %r, parent=%r, childname=%r, filenode=%r, metadata=%r)" %
1113 (existing_file, userpath, flags, _repr_flags(flags), parent, childname, filenode, metadata),
1116 assert metadata is None or 'readonly' in metadata, metadata
1118 writing = (flags & (FXF_WRITE | FXF_CREAT)) != 0
1120 direntry = self._direntry_for(parent, childname)
1122 direntry = self._direntry_for(filenode)
1124 d = self._sync_heisenfiles(userpath, direntry, ignore=existing_file)
1126 if not writing and (flags & FXF_READ) and filenode and not filenode.is_mutable() and filenode.get_size() <= SIZE_THRESHOLD:
1127 d.addCallback(lambda ign: ShortReadOnlySFTPFile(userpath, filenode, metadata))
1131 close_notify = self._remove_heisenfile
1133 d.addCallback(lambda ign: existing_file or GeneralSFTPFile(userpath, flags, close_notify, self._convergence))
1134 def _got_file(file):
1136 self._add_heisenfiles_by_direntry(direntry, [file])
1137 return file.open(parent=parent, childname=childname, filenode=filenode, metadata=metadata)
1138 d.addCallback(_got_file)
1141 def openFile(self, pathstring, flags, attrs):
1142 request = ".openFile(%r, %r = %r, %r)" % (pathstring, flags, _repr_flags(flags), attrs)
1143 self.log(request, level=OPERATIONAL)
1145 # This is used for both reading and writing.
1146 # First exclude invalid combinations of flags, and empty paths.
1148 if not (flags & (FXF_READ | FXF_WRITE)):
1149 def _bad_readwrite():
1150 raise SFTPError(FX_BAD_MESSAGE, "invalid file open flags: at least one of FXF_READ and FXF_WRITE must be set")
1151 return defer.execute(_bad_readwrite)
1153 if (flags & FXF_EXCL) and not (flags & FXF_CREAT):
1154 def _bad_exclcreat():
1155 raise SFTPError(FX_BAD_MESSAGE, "invalid file open flags: FXF_EXCL cannot be set without FXF_CREAT")
1156 return defer.execute(_bad_exclcreat)
1158 path = self._path_from_string(pathstring)
1160 def _emptypath(): raise SFTPError(FX_NO_SUCH_FILE, "path cannot be empty")
1161 return defer.execute(_emptypath)
1163 # The combination of flags is potentially valid.
1165 # To work around clients that have race condition bugs, a getAttr, rename, or
1166 # remove request following an 'open' request with FXF_WRITE or FXF_CREAT flags,
1167 # should succeed even if the 'open' request has not yet completed. So we now
1168 # synchronously add a file object into the self._heisenfiles dict, indexed
1169 # by its UTF-8 userpath. (We can't yet add it to the all_heisenfiles dict,
1170 # because we don't yet have a user-independent path for the file.) The file
1171 # object does not know its filenode, parent, or childname at this point.
1173 userpath = self._path_to_utf8(path)
1175 if flags & (FXF_WRITE | FXF_CREAT):
1176 file = GeneralSFTPFile(userpath, flags, self._remove_heisenfile, self._convergence)
1177 self._add_heisenfiles_by_path(userpath, [file])
1179 # We haven't decided which file implementation to use yet.
1182 # Now there are two major cases:
1184 # 1. The path is specified as /uri/FILECAP, with no parent directory.
1185 # If the FILECAP is mutable and writeable, then we can open it in write-only
1186 # or read/write mode (non-exclusively), otherwise we can only open it in
1187 # read-only mode. The open should succeed immediately as long as FILECAP is
1188 # a valid known filecap that grants the required permission.
1190 # 2. The path is specified relative to a parent. We find the parent dirnode and
1191 # get the child's URI and metadata if it exists. There are four subcases:
1192 # a. the child does not exist: FXF_CREAT must be set, and we must be able
1193 # to write to the parent directory.
1194 # b. the child exists but is not a valid known filecap: fail
1195 # c. the child is mutable: if we are trying to open it write-only or
1196 # read/write, then we must be able to write to the file.
1197 # d. the child is immutable: if we are trying to open it write-only or
1198 # read/write, then we must be able to write to the parent directory.
1200 # To reduce latency, open normally succeeds as soon as these conditions are
1201 # met, even though there might be a failure in downloading the existing file
1202 # or uploading a new one. However, there is an exception: if a file has been
1203 # written, then closed, and is now being reopened, then we have to delay the
1204 # open until the previous upload/publish has completed. This is necessary
1205 # because sshfs does not wait for the result of an FXF_CLOSE message before
1206 # reporting to the client that a file has been closed. It applies both to
1207 # mutable files, and to directory entries linked to an immutable file.
1209 # Note that the permission checks below are for more precise error reporting on
1210 # the open call; later operations would fail even if we did not make these checks.
1212 d = self._get_root(path)
1213 def _got_root( (root, path) ):
1214 if root.is_unknown():
1215 raise SFTPError(FX_PERMISSION_DENIED,
1216 "cannot open an unknown cap (or child of an unknown directory). "
1217 "Upgrading the gateway to a later Tahoe-LAFS version may help")
1220 if noisy: self.log("case 1: root = %r, path[:-1] = %r" % (root, path[:-1]), level=NOISY)
1221 if not IFileNode.providedBy(root):
1222 raise SFTPError(FX_PERMISSION_DENIED,
1223 "cannot open a directory cap")
1224 if (flags & FXF_WRITE) and root.is_readonly():
1225 raise SFTPError(FX_PERMISSION_DENIED,
1226 "cannot write to a non-writeable filecap without a parent directory")
1227 if flags & FXF_EXCL:
1228 raise SFTPError(FX_FAILURE,
1229 "cannot create a file exclusively when it already exists")
1231 # The file does not need to be added to all_heisenfiles, because it is not
1232 # associated with a directory entry that needs to be updated.
1234 return self._make_file(file, userpath, flags, filenode=root)
1237 childname = path[-1]
1238 if noisy: self.log("case 2: root = %r, childname = %r, path[:-1] = %r" %
1239 (root, childname, path[:-1]), level=NOISY)
1240 d2 = root.get_child_at_path(path[:-1])
1241 def _got_parent(parent):
1242 if noisy: self.log("_got_parent(%r)" % (parent,), level=NOISY)
1243 if parent.is_unknown():
1244 raise SFTPError(FX_PERMISSION_DENIED,
1245 "cannot open an unknown cap (or child of an unknown directory). "
1246 "Upgrading the gateway to a later Tahoe-LAFS version may help")
1248 parent_readonly = parent.is_readonly()
1249 d3 = defer.succeed(None)
1250 if flags & FXF_EXCL:
1251 # FXF_EXCL means that the link to the file (not the file itself) must
1252 # be created atomically wrt updates by this storage client.
1253 # That is, we need to create the link before returning success to the
1254 # SFTP open request (and not just on close, as would normally be the
1255 # case). We make the link initially point to a zero-length LIT file,
1256 # which is consistent with what might happen on a POSIX filesystem.
1259 raise SFTPError(FX_FAILURE,
1260 "cannot create a file exclusively when the parent directory is read-only")
1262 # 'overwrite=False' ensures failure if the link already exists.
1263 # FIXME: should use a single call to set_uri and return (child, metadata) (#1035)
1265 zero_length_lit = "URI:LIT:"
1266 if noisy: self.log("%r.set_uri(%r, None, readcap=%r, overwrite=False)" %
1267 (parent, zero_length_lit, childname), level=NOISY)
1268 d3.addCallback(lambda ign: parent.set_uri(childname, None, readcap=zero_length_lit, overwrite=False))
1269 def _seturi_done(child):
1270 if noisy: self.log("%r.get_metadata_for(%r)" % (parent, childname), level=NOISY)
1271 d4 = parent.get_metadata_for(childname)
1272 d4.addCallback(lambda metadata: (child, metadata))
1274 d3.addCallback(_seturi_done)
1276 if noisy: self.log("%r.get_child_and_metadata(%r)" % (parent, childname), level=NOISY)
1277 d3.addCallback(lambda ign: parent.get_child_and_metadata(childname))
1279 def _got_child( (filenode, metadata) ):
1280 if noisy: self.log("_got_child( (%r, %r) )" % (filenode, metadata), level=NOISY)
1282 if filenode.is_unknown():
1283 raise SFTPError(FX_PERMISSION_DENIED,
1284 "cannot open an unknown cap. Upgrading the gateway "
1285 "to a later Tahoe-LAFS version may help")
1286 if not IFileNode.providedBy(filenode):
1287 raise SFTPError(FX_PERMISSION_DENIED,
1288 "cannot open a directory as if it were a file")
1289 if (flags & FXF_WRITE) and filenode.is_mutable() and filenode.is_readonly():
1290 raise SFTPError(FX_PERMISSION_DENIED,
1291 "cannot open a read-only mutable file for writing")
1292 if (flags & FXF_WRITE) and parent_readonly:
1293 raise SFTPError(FX_PERMISSION_DENIED,
1294 "cannot open a file for writing when the parent directory is read-only")
1296 metadata['readonly'] = _is_readonly(parent_readonly, filenode)
1297 return self._make_file(file, userpath, flags, parent=parent, childname=childname,
1298 filenode=filenode, metadata=metadata)
1300 if noisy: self.log("_no_child(%r)" % (f,), level=NOISY)
1301 f.trap(NoSuchChildError)
1303 if not (flags & FXF_CREAT):
1304 raise SFTPError(FX_NO_SUCH_FILE,
1305 "the file does not exist, and was not opened with the creation (CREAT) flag")
1307 raise SFTPError(FX_PERMISSION_DENIED,
1308 "cannot create a file when the parent directory is read-only")
1310 return self._make_file(file, userpath, flags, parent=parent, childname=childname)
1311 d3.addCallbacks(_got_child, _no_child)
1314 d2.addCallback(_got_parent)
1317 d.addCallback(_got_root)
1318 def _remove_on_error(err):
1320 self._remove_heisenfile(userpath, None, None, file)
1322 d.addErrback(_remove_on_error)
1323 d.addBoth(_convert_error, request)
1326 def renameFile(self, from_pathstring, to_pathstring, overwrite=False):
1327 request = ".renameFile(%r, %r)" % (from_pathstring, to_pathstring)
1328 self.log(request, level=OPERATIONAL)
1330 from_path = self._path_from_string(from_pathstring)
1331 to_path = self._path_from_string(to_pathstring)
1332 from_userpath = self._path_to_utf8(from_path)
1333 to_userpath = self._path_to_utf8(to_path)
1335 # the target directory must already exist
1336 d = deferredutil.gatherResults([self._get_parent_or_node(from_path),
1337 self._get_parent_or_node(to_path)])
1338 def _got( (from_pair, to_pair) ):
1339 if noisy: self.log("_got( (%r, %r) ) in .renameFile(%r, %r, overwrite=%r)" %
1340 (from_pair, to_pair, from_pathstring, to_pathstring, overwrite), level=NOISY)
1341 (from_parent, from_childname) = from_pair
1342 (to_parent, to_childname) = to_pair
1344 if from_childname is None:
1345 raise SFTPError(FX_NO_SUCH_FILE, "cannot rename a source object specified by URI")
1346 if to_childname is None:
1347 raise SFTPError(FX_NO_SUCH_FILE, "cannot rename to a destination specified by URI")
1349 # <http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02#section-6.5>
1350 # "It is an error if there already exists a file with the name specified
1352 # OpenSSH's SFTP server returns FX_PERMISSION_DENIED for this error.
1354 # For the standard SSH_FXP_RENAME operation, overwrite=False.
1355 # We also support the posix-rename@openssh.com extension, which uses overwrite=True.
1357 d2 = defer.fail(NoSuchChildError())
1359 d2.addCallback(lambda ign: to_parent.get(to_childname))
1360 def _expect_fail(res):
1361 if not isinstance(res, Failure):
1362 raise SFTPError(FX_PERMISSION_DENIED, "cannot rename to existing path " + to_userpath)
1364 # It is OK if we fail for errors other than NoSuchChildError, since that probably
1365 # indicates some problem accessing the destination directory.
1366 res.trap(NoSuchChildError)
1367 d2.addBoth(_expect_fail)
1369 # If there are heisenfiles to be written at the 'from' direntry, then ensure
1370 # they will now be written at the 'to' direntry instead.
1371 d2.addCallback(lambda ign:
1372 self._rename_heisenfiles(from_userpath, from_parent, from_childname,
1373 to_userpath, to_parent, to_childname, overwrite=overwrite))
1376 # FIXME: use move_child_to_path to avoid possible data loss due to #943
1377 #d3 = from_parent.move_child_to_path(from_childname, to_root, to_path, overwrite=overwrite)
1379 d3 = from_parent.move_child_to(from_childname, to_parent, to_childname, overwrite=overwrite)
1381 if noisy: self.log("_check(%r) in .renameFile(%r, %r, overwrite=%r)" %
1382 (err, from_pathstring, to_pathstring, overwrite), level=NOISY)
1384 if not isinstance(err, Failure) or (renamed and err.check(NoSuchChildError)):
1386 if not overwrite and err.check(ExistingChildError):
1387 raise SFTPError(FX_PERMISSION_DENIED, "cannot rename to existing path " + to_userpath)
1392 d2.addCallback(_move)
1395 d.addBoth(_convert_error, request)
1398 def makeDirectory(self, pathstring, attrs):
1399 request = ".makeDirectory(%r, %r)" % (pathstring, attrs)
1400 self.log(request, level=OPERATIONAL)
1402 path = self._path_from_string(pathstring)
1403 metadata = self._attrs_to_metadata(attrs)
1404 d = self._get_root(path)
1405 d.addCallback(lambda (root, path):
1406 self._get_or_create_directories(root, path, metadata))
1407 d.addBoth(_convert_error, request)
1410 def _get_or_create_directories(self, node, path, metadata):
1411 if not IDirectoryNode.providedBy(node):
1412 # TODO: provide the name of the blocking file in the error message.
1413 def _blocked(): raise SFTPError(FX_FAILURE, "cannot create directory because there "
1414 "is a file in the way") # close enough
1415 return defer.execute(_blocked)
1418 return defer.succeed(node)
1419 d = node.get(path[0])
1420 def _maybe_create(f):
1421 f.trap(NoSuchChildError)
1422 return node.create_subdirectory(path[0])
1423 d.addErrback(_maybe_create)
1424 d.addCallback(self._get_or_create_directories, path[1:], metadata)
1427 def removeFile(self, pathstring):
1428 request = ".removeFile(%r)" % (pathstring,)
1429 self.log(request, level=OPERATIONAL)
1431 path = self._path_from_string(pathstring)
1432 d = self._remove_object(path, must_be_file=True)
1433 d.addBoth(_convert_error, request)
1436 def removeDirectory(self, pathstring):
1437 request = ".removeDirectory(%r)" % (pathstring,)
1438 self.log(request, level=OPERATIONAL)
1440 path = self._path_from_string(pathstring)
1441 d = self._remove_object(path, must_be_directory=True)
1442 d.addBoth(_convert_error, request)
1445 def _remove_object(self, path, must_be_directory=False, must_be_file=False):
1446 userpath = self._path_to_utf8(path)
1447 d = self._get_parent_or_node(path)
1448 def _got_parent( (parent, childname) ):
1449 if childname is None:
1450 raise SFTPError(FX_NO_SUCH_FILE, "cannot remove an object specified by URI")
1452 direntry = self._direntry_for(parent, childname)
1453 d2 = defer.succeed(False)
1454 if not must_be_directory:
1455 d2.addCallback(lambda ign: self._abandon_any_heisenfiles(userpath, direntry))
1457 d2.addCallback(lambda abandoned:
1458 parent.delete(childname, must_exist=not abandoned,
1459 must_be_directory=must_be_directory, must_be_file=must_be_file))
1461 d.addCallback(_got_parent)
1464 def openDirectory(self, pathstring):
1465 request = ".openDirectory(%r)" % (pathstring,)
1466 self.log(request, level=OPERATIONAL)
1468 path = self._path_from_string(pathstring)
1469 d = self._get_parent_or_node(path)
1470 def _got_parent_or_node( (parent_or_node, childname) ):
1471 if noisy: self.log("_got_parent_or_node( (%r, %r) ) in openDirectory(%r)" %
1472 (parent_or_node, childname, pathstring), level=NOISY)
1473 if childname is None:
1474 return parent_or_node
1476 return parent_or_node.get(childname)
1477 d.addCallback(_got_parent_or_node)
1479 if dirnode.is_unknown():
1480 raise SFTPError(FX_PERMISSION_DENIED,
1481 "cannot list an unknown cap as a directory. Upgrading the gateway "
1482 "to a later Tahoe-LAFS version may help")
1483 if not IDirectoryNode.providedBy(dirnode):
1484 raise SFTPError(FX_PERMISSION_DENIED,
1485 "cannot list a file as if it were a directory")
1488 def _render(children):
1489 parent_readonly = dirnode.is_readonly()
1491 for filename, (child, metadata) in children.iteritems():
1492 # The file size may be cached or absent.
1493 metadata['readonly'] = _is_readonly(parent_readonly, child)
1494 attrs = _populate_attrs(child, metadata)
1495 filename_utf8 = filename.encode('utf-8')
1496 longname = _lsLine(filename_utf8, attrs)
1497 results.append( (filename_utf8, longname, attrs) )
1498 return StoppableList(results)
1499 d2.addCallback(_render)
1501 d.addCallback(_list)
1502 d.addBoth(_convert_error, request)
1505 def getAttrs(self, pathstring, followLinks):
1506 request = ".getAttrs(%r, followLinks=%r)" % (pathstring, followLinks)
1507 self.log(request, level=OPERATIONAL)
1509 # When asked about a specific file, report its current size.
1510 # TODO: the modification time for a mutable file should be
1511 # reported as the update time of the best version. But that
1512 # information isn't currently stored in mutable shares, I think.
1514 # Some clients will incorrectly try to get the attributes
1515 # of a file immediately after opening it, before it has been put
1516 # into the all_heisenfiles table. This is a race condition bug in
1517 # the client, but we probably need to handle it anyway.
1519 path = self._path_from_string(pathstring)
1520 userpath = self._path_to_utf8(path)
1521 d = self._get_parent_or_node(path)
1522 def _got_parent_or_node( (parent_or_node, childname) ):
1523 if noisy: self.log("_got_parent_or_node( (%r, %r) )" % (parent_or_node, childname), level=NOISY)
1525 direntry = self._direntry_for(parent_or_node, childname)
1526 d2 = self._sync_heisenfiles(userpath, direntry)
1528 if childname is None:
1529 node = parent_or_node
1530 d2.addCallback(lambda ign: node.get_current_size())
1531 d2.addCallback(lambda size:
1532 _populate_attrs(node, {'readonly': node.is_unknown() or node.is_readonly()}, size=size))
1534 parent = parent_or_node
1535 d2.addCallback(lambda ign: parent.get_child_and_metadata_at_path([childname]))
1536 def _got( (child, metadata) ):
1537 if noisy: self.log("_got( (%r, %r) )" % (child, metadata), level=NOISY)
1538 assert IDirectoryNode.providedBy(parent), parent
1539 metadata['readonly'] = _is_readonly(parent.is_readonly(), child)
1540 d3 = child.get_current_size()
1541 d3.addCallback(lambda size: _populate_attrs(child, metadata, size=size))
1544 if noisy: self.log("_nosuch(%r)" % (err,), level=NOISY)
1545 err.trap(NoSuchChildError)
1546 direntry = self._direntry_for(parent, childname)
1547 if noisy: self.log("checking open files:\nself._heisenfiles = %r\nall_heisenfiles = %r\ndirentry=%r" %
1548 (self._heisenfiles, all_heisenfiles, direntry), level=NOISY)
1549 if direntry in all_heisenfiles:
1550 (files, opentime) = all_heisenfiles[direntry]
1551 sftptime = _to_sftp_time(opentime)
1552 # A file that has been opened for writing necessarily has permissions rw-rw-rw-.
1553 return {'permissions': S_IFREG | 0666,
1555 'createtime': sftptime,
1561 d2.addCallbacks(_got, _nosuch)
1563 d.addCallback(_got_parent_or_node)
1564 d.addBoth(_convert_error, request)
1567 def setAttrs(self, pathstring, attrs):
1568 self.log(".setAttrs(%r, %r)" % (pathstring, attrs), level=OPERATIONAL)
1571 # this would require us to download and re-upload the truncated/extended
1573 def _unsupported(): raise SFTPError(FX_OP_UNSUPPORTED, "setAttrs wth size attribute unsupported")
1574 return defer.execute(_unsupported)
1575 return defer.succeed(None)
1577 def readLink(self, pathstring):
1578 self.log(".readLink(%r)" % (pathstring,), level=OPERATIONAL)
1580 def _unsupported(): raise SFTPError(FX_OP_UNSUPPORTED, "readLink")
1581 return defer.execute(_unsupported)
1583 def makeLink(self, linkPathstring, targetPathstring):
1584 self.log(".makeLink(%r, %r)" % (linkPathstring, targetPathstring), level=OPERATIONAL)
1586 # If this is implemented, note the reversal of arguments described in point 7 of
1587 # <http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL?rev=1.15>.
1589 def _unsupported(): raise SFTPError(FX_OP_UNSUPPORTED, "makeLink")
1590 return defer.execute(_unsupported)
1592 def extendedRequest(self, extensionName, extensionData):
1593 self.log(".extendedRequest(%r, <data of length %r>)" % (extensionName, len(extensionData)), level=OPERATIONAL)
1595 # We implement the three main OpenSSH SFTP extensions; see
1596 # <http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL?rev=1.15>
1598 if extensionName == 'posix-rename@openssh.com':
1599 def _bad(): raise SFTPError(FX_BAD_MESSAGE, "could not parse posix-rename@openssh.com request")
1601 (fromPathLen,) = struct.unpack('>L', extensionData[0:4])
1602 if 8 + fromPathLen > len(extensionData): return defer.execute(_bad)
1604 (toPathLen,) = struct.unpack('>L', extensionData[(4 + fromPathLen):(8 + fromPathLen)])
1605 if 8 + fromPathLen + toPathLen != len(extensionData): return defer.execute(_bad)
1607 fromPathstring = extensionData[4:(4 + fromPathLen)]
1608 toPathstring = extensionData[(8 + fromPathLen):]
1609 d = self.renameFile(fromPathstring, toPathstring, overwrite=True)
1611 # Twisted conch assumes that the response from an extended request is either
1612 # an error, or an FXP_EXTENDED_REPLY. But it happens to do the right thing
1613 # (respond with an FXP_STATUS message) if we return a Failure with code FX_OK.
1614 def _succeeded(ign):
1615 raise SFTPError(FX_OK, "request succeeded")
1616 d.addCallback(_succeeded)
1619 if extensionName == 'statvfs@openssh.com' or extensionName == 'fstatvfs@openssh.com':
1620 return defer.succeed(struct.pack('>11Q',
1621 1024, # uint64 f_bsize /* file system block size */
1622 1024, # uint64 f_frsize /* fundamental fs block size */
1623 628318530, # uint64 f_blocks /* number of blocks (unit f_frsize) */
1624 314159265, # uint64 f_bfree /* free blocks in file system */
1625 314159265, # uint64 f_bavail /* free blocks for non-root */
1626 200000000, # uint64 f_files /* total file inodes */
1627 100000000, # uint64 f_ffree /* free file inodes */
1628 100000000, # uint64 f_favail /* free file inodes for non-root */
1629 0x1AF5, # uint64 f_fsid /* file system id */
1630 2, # uint64 f_flag /* bit mask = ST_NOSUID; not ST_RDONLY */
1631 65535, # uint64 f_namemax /* maximum filename length */
1634 def _unsupported(): raise SFTPError(FX_OP_UNSUPPORTED, "unsupported %r request <data of length %r>" %
1635 (extensionName, len(extensionData)))
1636 return defer.execute(_unsupported)
1638 def realPath(self, pathstring):
1639 self.log(".realPath(%r)" % (pathstring,), level=OPERATIONAL)
1641 return self._path_to_utf8(self._path_from_string(pathstring))
1643 def _path_to_utf8(self, path):
1644 return (u"/" + u"/".join(path)).encode('utf-8')
1646 def _path_from_string(self, pathstring):
1647 if noisy: self.log("CONVERT %r" % (pathstring,), level=NOISY)
1649 # The home directory is the root directory.
1650 pathstring = pathstring.strip("/")
1651 if pathstring == "" or pathstring == ".":
1654 path_utf8 = pathstring.split("/")
1656 # <http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02#section-6.2>
1657 # "Servers SHOULD interpret a path name component ".." as referring to
1658 # the parent directory, and "." as referring to the current directory."
1660 for p_utf8 in path_utf8:
1662 # ignore excess .. components at the root
1667 p = p_utf8.decode('utf-8', 'strict')
1668 except UnicodeError:
1669 raise SFTPError(FX_NO_SUCH_FILE, "path could not be decoded as UTF-8")
1672 if noisy: self.log(" PATH %r" % (path,), level=NOISY)
1675 def _get_root(self, path):
1676 # return Deferred (root, remaining_path)
1677 d = defer.succeed(None)
1678 if path and path[0] == u"uri":
1679 d.addCallback(lambda ign: self._client.create_node_from_uri(path[1].encode('utf-8')))
1680 d.addCallback(lambda root: (root, path[2:]))
1682 d.addCallback(lambda ign: (self._root, path))
1685 def _get_parent_or_node(self, path):
1686 # return Deferred (parent, childname) or (node, None)
1687 d = self._get_root(path)
1688 def _got_root( (root, remaining_path) ):
1689 if not remaining_path:
1692 d2 = root.get_child_at_path(remaining_path[:-1])
1693 d2.addCallback(lambda parent: (parent, remaining_path[-1]))
1695 d.addCallback(_got_root)
1698 def _attrs_to_metadata(self, attrs):
1702 if key == "mtime" or key == "ctime" or key == "createtime":
1703 metadata[key] = long(attrs[key])
1704 elif key.startswith("ext_"):
1705 metadata[key] = str(attrs[key])
1710 class SFTPUser(ConchUser, PrefixingLogMixin):
1711 implements(ISession)
1712 def __init__(self, check_abort, client, rootnode, username, convergence):
1713 ConchUser.__init__(self)
1714 PrefixingLogMixin.__init__(self, facility="tahoe.sftp")
1716 self.channelLookup["session"] = session.SSHSession
1717 self.subsystemLookup["sftp"] = FileTransferServer
1719 self.check_abort = check_abort
1720 self.client = client
1721 self.root = rootnode
1722 self.username = username
1723 self.convergence = convergence
1725 def getPty(self, terminal, windowSize, attrs):
1726 self.log(".getPty(%r, %r, %r)" % (terminal, windowSize, attrs), level=OPERATIONAL)
1727 raise NotImplementedError
1729 def openShell(self, protocol):
1730 self.log(".openShell(%r)" % (protocol,), level=OPERATIONAL)
1731 raise NotImplementedError
1733 def execCommand(self, protocol, cmd):
1734 self.log(".execCommand(%r, %r)" % (protocol, cmd), level=OPERATIONAL)
1735 raise NotImplementedError
1737 def windowChanged(self, newWindowSize):
1738 self.log(".windowChanged(%r)" % (newWindowSize,), level=OPERATIONAL)
1741 self.log(".eofReceived()", level=OPERATIONAL)
1744 self.log(".closed()", level=OPERATIONAL)
1747 # if you have an SFTPUser, and you want something that provides ISFTPServer,
1748 # then you get SFTPHandler(user)
1749 components.registerAdapter(SFTPHandler, SFTPUser, ISFTPServer)
1751 from auth import AccountURLChecker, AccountFileChecker, NeedRootcapLookupScheme
1754 implements(portal.IRealm)
1755 def __init__(self, client):
1756 self._client = client
1758 def requestAvatar(self, avatarID, mind, interface):
1759 assert interface == IConchUser, interface
1760 rootnode = self._client.create_node_from_uri(avatarID.rootcap)
1761 handler = SFTPUserHandler(self._client, rootnode, avatarID.username)
1762 return (interface, handler, handler.logout)
1765 class SFTPServer(service.MultiService):
1766 def __init__(self, client, accountfile, accounturl,
1767 sftp_portstr, pubkey_file, privkey_file):
1768 service.MultiService.__init__(self)
1770 r = Dispatcher(client)
1771 p = portal.Portal(r)
1774 c = AccountFileChecker(self, accountfile)
1775 p.registerChecker(c)
1777 c = AccountURLChecker(self, accounturl)
1778 p.registerChecker(c)
1779 if not accountfile and not accounturl:
1780 # we could leave this anonymous, with just the /uri/CAP form
1781 raise NeedRootcapLookupScheme("must provide an account file or URL")
1783 pubkey = keys.Key.fromFile(pubkey_file)
1784 privkey = keys.Key.fromFile(privkey_file)
1785 class SSHFactory(factory.SSHFactory):
1786 publicKeys = {pubkey.sshType(): pubkey}
1787 privateKeys = {privkey.sshType(): privkey}
1788 def getPrimes(self):
1790 # if present, this enables diffie-hellman-group-exchange
1791 return primes.parseModuliFile("/etc/ssh/moduli")
1798 s = strports.service(sftp_portstr, f)
1799 s.setServiceParent(self)