tahoe-lafs/src/allmydata/upload.py

669 lines
26 KiB
Python

import os
from zope.interface import implements
from twisted.python import log, failure
from twisted.internet import defer
from twisted.application import service
from foolscap import Referenceable
from allmydata.util.hashutil import file_renewal_secret_hash, \
file_cancel_secret_hash, bucket_renewal_secret_hash, \
bucket_cancel_secret_hash, plaintext_hasher, \
storage_index_chk_hash, plaintext_segment_hasher, key_hasher
from allmydata import encode, storage, hashtree, uri
from allmydata.util import idlib, mathutil
from allmydata.interfaces import IUploadable, IUploader, IEncryptedUploadable
from pycryptopp.cipher.aes import AES
from cStringIO import StringIO
class HaveAllPeersError(Exception):
# we use this to jump out of the loop
pass
# this wants to live in storage, not here
class TooFullError(Exception):
pass
# our current uri_extension is 846 bytes for small files, a few bytes
# more for larger ones (since the filesize is encoded in decimal in a
# few places). Ask for a little bit more just in case we need it. If
# the extension changes size, we can change EXTENSION_SIZE to
# allocate a more accurate amount of space.
EXTENSION_SIZE = 1000
class PeerTracker:
def __init__(self, peerid, permutedid, connection,
sharesize, blocksize, num_segments, num_share_hashes,
storage_index,
bucket_renewal_secret, bucket_cancel_secret):
self.peerid = peerid
self.permutedid = permutedid
self.connection = connection # to an RIClient
self.buckets = {} # k: shareid, v: IRemoteBucketWriter
self.sharesize = sharesize
#print "PeerTracker", peerid, permutedid, sharesize
as = storage.allocated_size(sharesize,
num_segments,
num_share_hashes,
EXTENSION_SIZE)
self.allocated_size = as
self.blocksize = blocksize
self.num_segments = num_segments
self.num_share_hashes = num_share_hashes
self.storage_index = storage_index
self._storageserver = None
self.renew_secret = bucket_renewal_secret
self.cancel_secret = bucket_cancel_secret
def __repr__(self):
return ("<PeerTracker for peer %s and SI %s>"
% (idlib.b2a(self.peerid)[:4],
idlib.b2a(self.storage_index)[:6]))
def query(self, sharenums):
if not self._storageserver:
d = self.connection.callRemote("get_service", "storageserver")
d.addCallback(self._got_storageserver)
d.addCallback(lambda res: self._query(sharenums))
return d
return self._query(sharenums)
def _got_storageserver(self, storageserver):
self._storageserver = storageserver
def _query(self, sharenums):
#print " query", self.peerid, len(sharenums)
d = self._storageserver.callRemote("allocate_buckets",
self.storage_index,
self.renew_secret,
self.cancel_secret,
sharenums,
self.allocated_size,
canary=Referenceable())
d.addCallback(self._got_reply)
return d
def _got_reply(self, (alreadygot, buckets)):
#log.msg("%s._got_reply(%s)" % (self, (alreadygot, buckets)))
b = {}
for sharenum, rref in buckets.iteritems():
bp = storage.WriteBucketProxy(rref, self.sharesize,
self.blocksize,
self.num_segments,
self.num_share_hashes,
EXTENSION_SIZE)
b[sharenum] = bp
self.buckets.update(b)
return (alreadygot, set(b.keys()))
class Tahoe2PeerSelector:
def __init__(self, upload_id):
self.upload_id = upload_id
self.query_count, self.good_query_count, self.bad_query_count = 0,0,0
self.error_count = 0
self.num_peers_contacted = 0
self.last_failure_msg = None
def __repr__(self):
return "<Tahoe2PeerSelector for upload %s>" % self.upload_id
def get_shareholders(self, client,
storage_index, share_size, block_size,
num_segments, total_shares, shares_of_happiness,
push_to_ourselves):
"""
@return: a set of PeerTracker instances that have agreed to hold some
shares for us
"""
self.total_shares = total_shares
self.shares_of_happiness = shares_of_happiness
self.homeless_shares = range(total_shares)
# self.uncontacted_peers = list() # peers we haven't asked yet
self.contacted_peers = [] # peers worth asking again
self.contacted_peers2 = [] # peers that we have asked again
self.use_peers = set() # PeerTrackers that have shares assigned to them
self.preexisting_shares = {} # sharenum -> PeerTracker holding the share
peers = client.get_permuted_peers(storage_index, push_to_ourselves)
if not peers:
raise encode.NotEnoughPeersError("client gave us zero peers")
# figure out how much space to ask for
# this needed_hashes computation should mirror
# Encoder.send_all_share_hash_trees. We use an IncompleteHashTree
# (instead of a HashTree) because we don't require actual hashing
# just to count the levels.
ht = hashtree.IncompleteHashTree(total_shares)
num_share_hashes = len(ht.needed_hashes(0, include_leaf=True))
# decide upon the renewal/cancel secrets, to include them in the
# allocat_buckets query.
client_renewal_secret = client.get_renewal_secret()
client_cancel_secret = client.get_cancel_secret()
file_renewal_secret = file_renewal_secret_hash(client_renewal_secret,
storage_index)
file_cancel_secret = file_cancel_secret_hash(client_cancel_secret,
storage_index)
trackers = [ PeerTracker(peerid, permutedid, conn,
share_size, block_size,
num_segments, num_share_hashes,
storage_index,
bucket_renewal_secret_hash(file_renewal_secret,
peerid),
bucket_cancel_secret_hash(file_cancel_secret,
peerid),
)
for permutedid, peerid, conn in peers ]
self.uncontacted_peers = trackers
d = defer.maybeDeferred(self._loop)
return d
def _loop(self):
if not self.homeless_shares:
# all done
msg = ("placed all %d shares, "
"sent %d queries to %d peers, "
"%d queries placed some shares, %d placed none, "
"got %d errors" %
(self.total_shares,
self.query_count, self.num_peers_contacted,
self.good_query_count, self.bad_query_count,
self.error_count))
log.msg("peer selection successful for %s: %s" % (self, msg))
return self.use_peers
if self.uncontacted_peers:
peer = self.uncontacted_peers.pop(0)
# TODO: don't pre-convert all peerids to PeerTrackers
assert isinstance(peer, PeerTracker)
shares_to_ask = set([self.homeless_shares.pop(0)])
self.query_count += 1
self.num_peers_contacted += 1
d = peer.query(shares_to_ask)
d.addBoth(self._got_response, peer, shares_to_ask,
self.contacted_peers)
return d
elif self.contacted_peers:
# ask a peer that we've already asked.
num_shares = mathutil.div_ceil(len(self.homeless_shares),
len(self.contacted_peers))
peer = self.contacted_peers.pop(0)
shares_to_ask = set(self.homeless_shares[:num_shares])
self.homeless_shares[:num_shares] = []
self.query_count += 1
d = peer.query(shares_to_ask)
d.addBoth(self._got_response, peer, shares_to_ask,
self.contacted_peers2)
return d
elif self.contacted_peers2:
# we've finished the second-or-later pass. Move all the remaining
# peers back into self.contacted_peers for the next pass.
self.contacted_peers.extend(self.contacted_peers2)
self.contacted_peers[:] = []
return self._loop()
else:
# no more peers. If we haven't placed enough shares, we fail.
placed_shares = self.total_shares - len(self.homeless_shares)
if placed_shares < self.shares_of_happiness:
msg = ("placed %d shares out of %d total (%d homeless), "
"sent %d queries to %d peers, "
"%d queries placed some shares, %d placed none, "
"got %d errors" %
(self.total_shares - len(self.homeless_shares),
self.total_shares, len(self.homeless_shares),
self.query_count, self.num_peers_contacted,
self.good_query_count, self.bad_query_count,
self.error_count))
msg = "peer selection failed for %s: %s" % (self, msg)
if self.last_failure_msg:
msg += " (%s)" % (self.last_failure_msg,)
log.msg(msg)
raise encode.NotEnoughPeersError(msg)
else:
# we placed enough to be happy, so we're done
return self.use_peers
def _got_response(self, res, peer, shares_to_ask, put_peer_here):
if isinstance(res, failure.Failure):
# This is unusual, and probably indicates a bug or a network
# problem.
log.msg("%s got error during peer selection: %s" % (peer, res))
self.error_count += 1
self.homeless_shares = list(shares_to_ask) + self.homeless_shares
if (self.uncontacted_peers
or self.contacted_peers
or self.contacted_peers2):
# there is still hope, so just loop
pass
else:
# No more peers, so this upload might fail (it depends upon
# whether we've hit shares_of_happiness or not). Log the last
# failure we got: if a coding error causes all peers to fail
# in the same way, this allows the common failure to be seen
# by the uploader and should help with debugging
msg = ("last failure (from %s) was: %s" % (peer, res))
self.last_failure_msg = msg
else:
(alreadygot, allocated) = res
progress = False
for s in alreadygot:
self.preexisting_shares[s] = peer
if s in self.homeless_shares:
self.homeless_shares.remove(s)
progress = True
# the PeerTracker will remember which shares were allocated on
# that peer. We just have to remember to use them.
if allocated:
self.use_peers.add(peer)
progress = True
not_yet_present = set(shares_to_ask) - set(alreadygot)
still_homeless = not_yet_present - set(allocated)
if progress:
# they accepted or already had at least one share, so
# progress has been made
self.good_query_count += 1
else:
self.bad_query_count += 1
if still_homeless:
# In networks with lots of space, this is very unusual and
# probably indicates an error. In networks with peers that
# are full, it is merely unusual. In networks that are very
# full, it is common, and many uploads will fail. In most
# cases, this is obviously not fatal, and we'll just use some
# other peers.
# some shares are still homeless, keep trying to find them a
# home. The ones that were rejected get first priority.
self.homeless_shares = (list(still_homeless)
+ self.homeless_shares)
# Since they were unable to accept all of our requests, so it
# is safe to assume that asking them again won't help.
else:
# if they *were* able to accept everything, they might be
# willing to accept even more.
put_peer_here.append(peer)
# now loop
return self._loop()
class EncryptAnUploadable:
"""This is a wrapper that takes an IUploadable and provides
IEncryptedUploadable."""
implements(IEncryptedUploadable)
def __init__(self, original):
self.original = original
self._encryptor = None
self._plaintext_hasher = plaintext_hasher()
self._plaintext_segment_hasher = None
self._plaintext_segment_hashes = []
self._params = None
def get_size(self):
return self.original.get_size()
def set_serialized_encoding_parameters(self, params):
self._params = params
def _get_encryptor(self):
if self._encryptor:
return defer.succeed(self._encryptor)
if self._params is not None:
self.original.set_serialized_encoding_parameters(self._params)
d = self.original.get_encryption_key()
def _got(key):
e = AES(key)
self._encryptor = e
storage_index = storage_index_chk_hash(key)
assert isinstance(storage_index, str)
# There's no point to having the SI be longer than the key, so we
# specify that it is truncated to the same 128 bits as the AES key.
assert len(storage_index) == 16 # SHA-256 truncated to 128b
self._storage_index = storage_index
return e
d.addCallback(_got)
return d
def get_storage_index(self):
d = self._get_encryptor()
d.addCallback(lambda res: self._storage_index)
return d
def set_segment_size(self, segsize):
self._segment_size = segsize
def _get_segment_hasher(self):
p = self._plaintext_segment_hasher
if p:
left = self._segment_size - self._plaintext_segment_hashed_bytes
return p, left
p = plaintext_segment_hasher()
self._plaintext_segment_hasher = p
self._plaintext_segment_hashed_bytes = 0
return p, self._segment_size
def _update_segment_hash(self, chunk):
offset = 0
while offset < len(chunk):
p, segment_left = self._get_segment_hasher()
chunk_left = len(chunk) - offset
this_segment = min(chunk_left, segment_left)
p.update(chunk[offset:offset+this_segment])
self._plaintext_segment_hashed_bytes += this_segment
if self._plaintext_segment_hashed_bytes == self._segment_size:
# we've filled this segment
self._plaintext_segment_hashes.append(p.digest())
self._plaintext_segment_hasher = None
offset += this_segment
def read_encrypted(self, length):
d = self._get_encryptor()
d.addCallback(lambda res: self.original.read(length))
def _got(data):
assert isinstance(data, (tuple, list)), type(data)
data = list(data)
cryptdata = []
# we use data.pop(0) instead of 'for chunk in data' to save
# memory: each chunk is destroyed as soon as we're done with it.
while data:
chunk = data.pop(0)
self._plaintext_hasher.update(chunk)
self._update_segment_hash(chunk)
cryptdata.append(self._encryptor.process(chunk))
del chunk
return cryptdata
d.addCallback(_got)
return d
def get_plaintext_segment_hashtree_nodes(self, num_segments):
if len(self._plaintext_segment_hashes) < num_segments:
# close out the last one
assert len(self._plaintext_segment_hashes) == num_segments-1
p, segment_left = self._get_segment_hasher()
self._plaintext_segment_hashes.append(p.digest())
del self._plaintext_segment_hasher
assert len(self._plaintext_segment_hashes) == num_segments
ht = hashtree.HashTree(self._plaintext_segment_hashes)
return defer.succeed(list(ht))
def get_plaintext_hash(self):
h = self._plaintext_hasher.digest()
return defer.succeed(h)
class CHKUploader:
peer_selector_class = Tahoe2PeerSelector
def __init__(self, client, options={}, wait_for_numpeers=None):
assert wait_for_numpeers is None or isinstance(wait_for_numpeers, int), wait_for_numpeers
self._client = client
self._wait_for_numpeers = wait_for_numpeers
self._options = options
self._log_number = self._client.log("CHKUploader starting")
def set_params(self, encoding_parameters):
self._encoding_parameters = encoding_parameters
def log(self, msg, parent=None):
if parent is None:
parent = self._log_number
return self._client.log(msg, parent=parent)
def start(self, uploadable):
"""Start uploading the file.
This method returns a Deferred that will fire with the URI (a
string)."""
uploadable = IUploadable(uploadable)
self.log("starting upload of %s" % uploadable)
eu = EncryptAnUploadable(uploadable)
d = self.start_encrypted(eu)
def _uploaded(res):
d1 = uploadable.get_encryption_key()
d1.addCallback(lambda key: self._compute_uri(res, key))
return d1
d.addCallback(_uploaded)
return d
def start_encrypted(self, encrypted):
eu = IEncryptedUploadable(encrypted)
e = encode.Encoder(self._options, self)
e.set_params(self._encoding_parameters)
d = e.set_encrypted_uploadable(eu)
def _wait_for_peers(res):
wait_for_numpeers = self._wait_for_numpeers
if wait_for_numpeers is None:
# wait_for_numpeers = e.get_param("share_counts")[0] # XXX
wait_for_numpeers = 1
d1 = self._client.introducer_client.when_enough_peers(wait_for_numpeers)
d1.addCallback(lambda dummy: res)
return d1
d.addCallback(_wait_for_peers)
d.addCallback(self.locate_all_shareholders)
d.addCallback(self.set_shareholders, e)
d.addCallback(lambda res: e.start())
# this fires with the uri_extension_hash and other data
return d
def locate_all_shareholders(self, encoder):
storage_index = encoder.get_param("storage_index")
upload_id = idlib.b2a(storage_index)[:6]
self.log("using storage index %s" % upload_id)
peer_selector = self.peer_selector_class(upload_id)
share_size = encoder.get_param("share_size")
block_size = encoder.get_param("block_size")
num_segments = encoder.get_param("num_segments")
k,desired,n = encoder.get_param("share_counts")
push_to_ourselves = self._options.get("push_to_ourselves", False)
gs = peer_selector.get_shareholders
d = gs(self._client, storage_index, share_size, block_size,
num_segments, n, desired, push_to_ourselves)
return d
def set_shareholders(self, used_peers, encoder):
"""
@param used_peers: a sequence of PeerTracker objects
"""
self.log("_send_shares, used_peers is %s" % (used_peers,))
for peer in used_peers:
assert isinstance(peer, PeerTracker)
buckets = {}
for peer in used_peers:
buckets.update(peer.buckets)
assert len(buckets) == sum([len(peer.buckets) for peer in used_peers])
encoder.set_shareholders(buckets)
def _compute_uri(self, (uri_extension_hash,
needed_shares, total_shares, size),
key):
u = uri.CHKFileURI(key=key,
uri_extension_hash=uri_extension_hash,
needed_shares=needed_shares,
total_shares=total_shares,
size=size,
)
return u.to_string()
def read_this_many_bytes(uploadable, size, prepend_data=[]):
if size == 0:
return defer.succeed([])
d = uploadable.read(size)
def _got(data):
assert isinstance(data, list)
bytes = sum([len(piece) for piece in data])
assert bytes > 0
assert bytes <= size
remaining = size - bytes
if remaining:
return read_this_many_bytes(uploadable, remaining,
prepend_data + data)
return prepend_data + data
d.addCallback(_got)
return d
class LiteralUploader:
def __init__(self, client, wait_for_numpeers, options={}):
self._client = client
self._options = options
def set_params(self, encoding_parameters):
pass
def start(self, uploadable):
uploadable = IUploadable(uploadable)
d = uploadable.get_size()
d.addCallback(lambda size: read_this_many_bytes(uploadable, size))
d.addCallback(lambda data: uri.LiteralFileURI("".join(data)))
d.addCallback(lambda u: u.to_string())
return d
def close(self):
pass
class ConvergentUploadMixin:
# to use this, the class it is mixed in to must have a seekable
# filehandle named self._filehandle
_params = None
_key = None
def set_serialized_encoding_parameters(self, params):
self._params = params
# ignored for now
def get_encryption_key(self):
if self._key is None:
f = self._filehandle
enckey_hasher = key_hasher()
#enckey_hasher.update(encoding_parameters) # TODO
f.seek(0)
BLOCKSIZE = 64*1024
while True:
data = f.read(BLOCKSIZE)
if not data:
break
enckey_hasher.update(data)
f.seek(0)
self._key = enckey_hasher.digest()[:16]
return defer.succeed(self._key)
class NonConvergentUploadMixin:
_key = None
def set_serialized_encoding_parameters(self, params):
pass
def get_encryption_key(self):
if self._key is None:
self._key = os.urandom(16)
return defer.succeed(self._key)
class FileHandle(ConvergentUploadMixin):
implements(IUploadable)
def __init__(self, filehandle):
self._filehandle = filehandle
def get_size(self):
self._filehandle.seek(0,2)
size = self._filehandle.tell()
self._filehandle.seek(0)
return defer.succeed(size)
def read(self, length):
return defer.succeed([self._filehandle.read(length)])
def close(self):
# the originator of the filehandle reserves the right to close it
pass
class FileName(FileHandle):
def __init__(self, filename):
FileHandle.__init__(self, open(filename, "rb"))
def close(self):
FileHandle.close(self)
self._filehandle.close()
class Data(FileHandle):
def __init__(self, data):
FileHandle.__init__(self, StringIO(data))
class Uploader(service.MultiService):
"""I am a service that allows file uploading.
"""
implements(IUploader)
name = "uploader"
uploader_class = CHKUploader
URI_LIT_SIZE_THRESHOLD = 55
DEFAULT_ENCODING_PARAMETERS = (25, 75, 100)
# this is a tuple of (needed, desired, total). 'needed' is the number of
# shares required to reconstruct a file. 'desired' means that we will
# abort an upload unless we can allocate space for at least this many.
# 'total' is the total number of shares created by encoding. If everybody
# has room then this is is how many we will upload.
def upload(self, uploadable, options={}, wait_for_numpeers=None):
assert wait_for_numpeers is None or isinstance(wait_for_numpeers, int), wait_for_numpeers
# this returns the URI
assert self.parent
assert self.running
push_to_ourselves = self.parent.get_push_to_ourselves()
if push_to_ourselves is not None:
options["push_to_ourselves"] = push_to_ourselves
uploadable = IUploadable(uploadable)
d = uploadable.get_size()
def _got_size(size):
uploader_class = self.uploader_class
if size <= self.URI_LIT_SIZE_THRESHOLD:
uploader_class = LiteralUploader
uploader = uploader_class(self.parent, options, wait_for_numpeers)
uploader.set_params(self.parent.get_encoding_parameters()
or self.DEFAULT_ENCODING_PARAMETERS)
return uploader.start(uploadable)
d.addCallback(_got_size)
def _done(res):
uploadable.close()
return res
d.addBoth(_done)
return d
# utility functions
def upload_data(self, data, options={}):
return self.upload(Data(data), options)
def upload_filename(self, filename, options={}):
return self.upload(FileName(filename), options)
def upload_filehandle(self, filehandle, options={}):
return self.upload(FileHandle(filehandle), options)