From: Brian Warner Date: Fri, 2 Nov 2007 06:46:47 +0000 (-0700) Subject: mutable: split dirnode stuff out to dirnode2.py, will be renamed later X-Git-Tag: allmydata-tahoe-0.7.0~297 X-Git-Url: https://git.rkrishnan.org/components/%22news.html/?a=commitdiff_plain;h=d772ea850d5fa692807b62a9afea01ecf478a61f;p=tahoe-lafs%2Ftahoe-lafs.git mutable: split dirnode stuff out to dirnode2.py, will be renamed later --- diff --git a/src/allmydata/client.py b/src/allmydata/client.py index 6dbb8598..5fde8980 100644 --- a/src/allmydata/client.py +++ b/src/allmydata/client.py @@ -210,14 +210,14 @@ class Client(node.Node, Referenceable, testutil.PollMixin): def create_empty_dirnode(self): - from allmydata.mutable import NewDirectoryNode + from allmydata.dirnode2 import NewDirectoryNode n = NewDirectoryNode(self) d = n.create() d.addCallback(lambda res: n) return d def create_dirnode_from_uri(self, u): - from allmydata.mutable import NewDirectoryNode + from allmydata.dirnode2 import NewDirectoryNode return NewDirectoryNode(self).init_from_uri(u) def create_mutable_file(self, contents=""): diff --git a/src/allmydata/dirnode2.py b/src/allmydata/dirnode2.py new file mode 100644 index 00000000..21eeeddc --- /dev/null +++ b/src/allmydata/dirnode2.py @@ -0,0 +1,351 @@ + +import os + +from zope.interface import implements +from twisted.internet import defer +import simplejson +from allmydata.interfaces import IMutableFileNode, IDirectoryNode,\ + IMutableFileURI, INewDirectoryURI, IURI, IFileNode, NotMutableError, \ + IVerifierURI +from allmydata.util import hashutil +from allmydata.util.hashutil import netstring +from allmydata.dirnode import IntegrityCheckError, FileNode +from allmydata.uri import NewDirectoryURI +from allmydata.Crypto.Cipher import AES + +from allmydata.mutable import MutableFileNode + +def split_netstring(data, numstrings, allow_leftover=False): + """like string.split(), but extracts netstrings. If allow_leftover=False, + returns numstrings elements, and throws ValueError if there was leftover + data. If allow_leftover=True, returns numstrings+1 elements, in which the + last element is the leftover data (possibly an empty string)""" + elements = [] + assert numstrings >= 0 + while data: + colon = data.index(":") + length = int(data[:colon]) + string = data[colon+1:colon+1+length] + assert len(string) == length + elements.append(string) + assert data[colon+1+length] == "," + data = data[colon+1+length+1:] + if len(elements) == numstrings: + break + if len(elements) < numstrings: + raise ValueError("ran out of netstrings") + if allow_leftover: + return tuple(elements + [data]) + if data: + raise ValueError("leftover data in netstrings") + return tuple(elements) + +class NewDirectoryNode: + implements(IDirectoryNode) + filenode_class = MutableFileNode + + def __init__(self, client): + self._client = client + def init_from_uri(self, myuri): + u = INewDirectoryURI(myuri) + self._uri = u + self._node = self.filenode_class(self._client) + self._node.init_from_uri(u.get_filenode_uri()) + return self + + def create(self): + # first we create a MutableFileNode with empty_contents, then use its + # URI to create our own. + self._node = self.filenode_class(self._client) + empty_contents = self._pack_contents({}) + d = self._node.create(empty_contents) + d.addCallback(self._filenode_created) + return d + def _filenode_created(self, res): + self._uri = NewDirectoryURI(self._node._uri) + return None + + def _read(self): + d = self._node.download_to_data() + d.addCallback(self._unpack_contents) + return d + + def _encrypt_rwcap(self, rwcap): + assert isinstance(rwcap, str) + IV = os.urandom(16) + key = hashutil.mutable_rwcap_key_hash(IV, self._node.writekey) + counterstart = "\x00"*16 + cryptor = AES.new(key=key, mode=AES.MODE_CTR, counterstart=counterstart) + crypttext = cryptor.encrypt(rwcap) + mac = hashutil.hmac(key, IV + crypttext) + assert len(mac) == 32 + return IV + crypttext + mac + + def _decrypt_rwcapdata(self, encwrcap): + IV = encwrcap[:16] + crypttext = encwrcap[16:-32] + mac = encwrcap[-32:] + key = hashutil.mutable_rwcap_key_hash(IV, self._node.writekey) + if mac != hashutil.hmac(key, IV+crypttext): + raise IntegrityCheckError("HMAC does not match, crypttext is corrupted") + counterstart = "\x00"*16 + cryptor = AES.new(key=key, mode=AES.MODE_CTR, counterstart=counterstart) + plaintext = cryptor.decrypt(crypttext) + return plaintext + + def _create_node(self, child_uri): + u = IURI(child_uri) + if INewDirectoryURI.providedBy(u): + return self._client.create_dirnode_from_uri(u) + if IFileNode.providedBy(u): + return self._client.create_file_from_uri(u) + if IMutableFileURI.providedBy(u): + return self._client.create_mutable_file_from_uri(u) + raise TypeError("cannot handle '%s' URI" % (u.__class__,)) + + def _unpack_contents(self, data): + # the directory is serialized as a list of netstrings, one per child. + # Each child is serialized as a list of four netstrings: (name, + # rocap, rwcap, metadata), in which the name,rocap,metadata are in + # cleartext. The rwcap is formatted as: + # pack("16ss32s", iv, AES(H(writekey+iv), plaintextrwcap), mac) + assert isinstance(data, str) + # an empty directory is serialized as an empty string + if data == "": + return {} + mutable = self.is_mutable() + children = {} + while len(data) > 0: + entry, data = split_netstring(data, 1, True) + name, rocap, rwcapdata, metadata_s = split_netstring(entry, 4) + if mutable: + rwcap = self._decrypt_rwcapdata(rwcapdata) + child = self._create_node(rwcap) + else: + child = self._create_node(rocap) + metadata = simplejson.loads(metadata_s) + assert isinstance(metadata, dict) + children[name] = (child, metadata) + return children + + def _pack_contents(self, children): + # expects children in the same format as _unpack_contents + assert isinstance(children, dict) + entries = [] + for name in sorted(children.keys()): + child, metadata = children[name] + assert (IFileNode.providedBy(child) + or IMutableFileNode.providedBy(child) + or IDirectoryNode.providedBy(child)) + assert isinstance(metadata, dict) + rwcap = child.get_uri() # might be RO if the child is not mutable + rocap = child.get_readonly() + entry = "".join([netstring(name), + netstring(rocap), + netstring(self._encrypt_rwcap(rwcap)), + netstring(simplejson.dumps(metadata))]) + entries.append(netstring(entry)) + return "".join(entries) + + def is_readonly(self): + return self._node.is_readonly() + def is_mutable(self): + return self._node.is_mutable() + + def get_uri(self): + return self._uri.to_string() + + def get_readonly(self): + return self._uri.get_readonly().to_string() + + def get_immutable_uri(self): + return self._uri.get_readonly().to_string() + + def get_verifier(self): + return self._uri.get_verifier().to_string() + + def check(self): + """Perform a file check. See IChecker.check for details.""" + pass # TODO + + def list(self): + """I return a Deferred that fires with a dictionary mapping child + name to an IFileNode or IDirectoryNode.""" + return self._read() + + def has_child(self, name): + """I return a Deferred that fires with a boolean, True if there + exists a child of the given name, False if not.""" + d = self._read() + d.addCallback(lambda children: children.has_key(name)) + return d + + def get(self, name): + """I return a Deferred that fires with a specific named child node, + either an IFileNode or an IDirectoryNode.""" + d = self._read() + d.addCallback(lambda children: children[name][0]) + return d + + def get_metadata_for(self, name): + d = self._read() + d.addCallback(lambda children: children[name][1]) + return d + + def get_child_at_path(self, path): + """Transform a child path into an IDirectoryNode or IFileNode. + + I perform a recursive series of 'get' operations to find the named + descendant node. I return a Deferred that fires with the node, or + errbacks with IndexError if the node could not be found. + + The path can be either a single string (slash-separated) or a list of + path-name elements. + """ + + if not path: + return defer.succeed(self) + if isinstance(path, (str, unicode)): + path = path.split("/") + childname = path[0] + remaining_path = path[1:] + d = self.get(childname) + if remaining_path: + def _got(node): + return node.get_child_at_path(remaining_path) + d.addCallback(_got) + return d + + def set_uri(self, name, child_uri, metadata={}): + """I add a child (by URI) at the specific name. I return a Deferred + that fires when the operation finishes. I will replace any existing + child of the same name. + + The child_uri could be for a file, or for a directory (either + read-write or read-only, using a URI that came from get_uri() ). + + If this directory node is read-only, the Deferred will errback with a + NotMutableError.""" + return self.set_node(name, self._create_node(child_uri), metadata) + + def set_node(self, name, child, metadata={}): + """I add a child at the specific name. I return a Deferred that fires + when the operation finishes. This Deferred will fire with the child + node that was just added. I will replace any existing child of the + same name. + + If this directory node is read-only, the Deferred will errback with a + NotMutableError.""" + if self.is_readonly(): + return defer.fail(NotMutableError()) + d = self._read() + def _add(children): + children[name] = (child, metadata) + new_contents = self._pack_contents(children) + return self._node.replace(new_contents) + d.addCallback(_add) + d.addCallback(lambda res: None) + return d + + def add_file(self, name, uploadable): + """I upload a file (using the given IUploadable), then attach the + resulting FileNode to the directory at the given name. I return a + Deferred that fires (with the IFileNode of the uploaded file) when + the operation completes.""" + if self.is_readonly(): + return defer.fail(NotMutableError()) + uploader = self._client.getServiceNamed("uploader") + d = uploader.upload(uploadable) + d.addCallback(lambda uri: self.set_node(name, + FileNode(uri, self._client))) + return d + + def delete(self, name): + """I remove the child at the specific name. I return a Deferred that + fires (with the node just removed) when the operation finishes.""" + if self.is_readonly(): + return defer.fail(NotMutableError()) + d = self._read() + def _delete(children): + old_child, metadata = children[name] + del children[name] + new_contents = self._pack_contents(children) + d = self._node.replace(new_contents) + def _done(res): + return old_child + d.addCallback(_done) + return d + d.addCallback(_delete) + return d + + def create_empty_directory(self, name): + """I create and attach an empty directory at the given name. I return + a Deferred that fires (with the new directory node) when the + operation finishes.""" + if self.is_readonly(): + return defer.fail(NotMutableError()) + d = self._client.create_empty_dirnode() + def _created(child): + d = self.set_node(name, child) + d.addCallback(lambda res: child) + return d + d.addCallback(_created) + return d + + def move_child_to(self, current_child_name, new_parent, + new_child_name=None): + """I take one of my children and move them to a new parent. The child + is referenced by name. On the new parent, the child will live under + 'new_child_name', which defaults to 'current_child_name'. I return a + Deferred that fires when the operation finishes.""" + if self.is_readonly() or new_parent.is_readonly(): + return defer.fail(NotMutableError()) + if new_child_name is None: + new_child_name = current_child_name + d = self.get(current_child_name) + d.addCallback(lambda child: new_parent.set_node(new_child_name, child)) + d.addCallback(lambda child: self.delete(current_child_name)) + return d + + def build_manifest(self): + """Return a frozenset of verifier-capability strings for all nodes + (directories and files) reachable from this one.""" + + # this is just a tree-walker, except that following each edge + # requires a Deferred. + + manifest = set() + manifest.add(self.get_verifier()) + + d = self._build_manifest_from_node(self, manifest) + def _done(res): + # LIT nodes have no verifier-capability: their data is stored + # inside the URI itself, so there is no need to refresh anything. + # They indicate this by returning None from their get_verifier + # method. We need to remove any such Nones from our set. We also + # want to convert all these caps into strings. + return frozenset([IVerifierURI(cap).to_string() + for cap in manifest + if cap is not None]) + d.addCallback(_done) + return d + + def _build_manifest_from_node(self, node, manifest): + d = node.list() + def _got_list(res): + dl = [] + for name, (child, metadata) in res.iteritems(): + verifier = child.get_verifier() + if verifier not in manifest: + manifest.add(verifier) + if IDirectoryNode.providedBy(child): + dl.append(self._build_manifest_from_node(child, + manifest)) + if dl: + return defer.DeferredList(dl) + d.addCallback(_got_list) + return d + +# use client.create_dirnode() to make one of these + + diff --git a/src/allmydata/mutable.py b/src/allmydata/mutable.py index d6757c81..b4b86035 100644 --- a/src/allmydata/mutable.py +++ b/src/allmydata/mutable.py @@ -1,16 +1,9 @@ -import os from zope.interface import implements from twisted.internet import defer -import simplejson -from allmydata.interfaces import IMutableFileNode, IDirectoryNode,\ - IMutableFileURI, INewDirectoryURI, IURI, IFileNode, NotMutableError, \ - IVerifierURI +from allmydata.interfaces import IMutableFileNode, IMutableFileURI from allmydata.util import hashutil -from allmydata.util.hashutil import netstring -from allmydata.dirnode import IntegrityCheckError, FileNode -from allmydata.uri import WriteableSSKFileURI, NewDirectoryURI -from allmydata.Crypto.Cipher import AES +from allmydata.uri import WriteableSSKFileURI class MutableFileNode: implements(IMutableFileNode) @@ -76,337 +69,3 @@ class MutableFileNode: return defer.succeed(None) # use client.create_mutable_file() to make one of these - -def split_netstring(data, numstrings, allow_leftover=False): - """like string.split(), but extracts netstrings. If allow_leftover=False, - returns numstrings elements, and throws ValueError if there was leftover - data. If allow_leftover=True, returns numstrings+1 elements, in which the - last element is the leftover data (possibly an empty string)""" - elements = [] - assert numstrings >= 0 - while data: - colon = data.index(":") - length = int(data[:colon]) - string = data[colon+1:colon+1+length] - assert len(string) == length - elements.append(string) - assert data[colon+1+length] == "," - data = data[colon+1+length+1:] - if len(elements) == numstrings: - break - if len(elements) < numstrings: - raise ValueError("ran out of netstrings") - if allow_leftover: - return tuple(elements + [data]) - if data: - raise ValueError("leftover data in netstrings") - return tuple(elements) - -class NewDirectoryNode: - implements(IDirectoryNode) - filenode_class = MutableFileNode - - def __init__(self, client): - self._client = client - def init_from_uri(self, myuri): - u = INewDirectoryURI(myuri) - self._uri = u - self._node = self.filenode_class(self._client) - self._node.init_from_uri(u.get_filenode_uri()) - return self - - def create(self): - # first we create a MutableFileNode with empty_contents, then use its - # URI to create our own. - self._node = self.filenode_class(self._client) - empty_contents = self._pack_contents({}) - d = self._node.create(empty_contents) - d.addCallback(self._filenode_created) - return d - def _filenode_created(self, res): - self._uri = NewDirectoryURI(self._node._uri) - return None - - def _read(self): - d = self._node.download_to_data() - d.addCallback(self._unpack_contents) - return d - - def _encrypt_rwcap(self, rwcap): - assert isinstance(rwcap, str) - IV = os.urandom(16) - key = hashutil.mutable_rwcap_key_hash(IV, self._node.writekey) - counterstart = "\x00"*16 - cryptor = AES.new(key=key, mode=AES.MODE_CTR, counterstart=counterstart) - crypttext = cryptor.encrypt(rwcap) - mac = hashutil.hmac(key, IV + crypttext) - assert len(mac) == 32 - return IV + crypttext + mac - - def _decrypt_rwcapdata(self, encwrcap): - IV = encwrcap[:16] - crypttext = encwrcap[16:-32] - mac = encwrcap[-32:] - key = hashutil.mutable_rwcap_key_hash(IV, self._node.writekey) - if mac != hashutil.hmac(key, IV+crypttext): - raise IntegrityCheckError("HMAC does not match, crypttext is corrupted") - counterstart = "\x00"*16 - cryptor = AES.new(key=key, mode=AES.MODE_CTR, counterstart=counterstart) - plaintext = cryptor.decrypt(crypttext) - return plaintext - - def _create_node(self, child_uri): - u = IURI(child_uri) - if INewDirectoryURI.providedBy(u): - return self._client.create_dirnode_from_uri(u) - if IFileNode.providedBy(u): - return self._client.create_file_from_uri(u) - if IMutableFileURI.providedBy(u): - return self._client.create_mutable_file_from_uri(u) - raise TypeError("cannot handle '%s' URI" % (u.__class__,)) - - def _unpack_contents(self, data): - # the directory is serialized as a list of netstrings, one per child. - # Each child is serialized as a list of four netstrings: (name, - # rocap, rwcap, metadata), in which the name,rocap,metadata are in - # cleartext. The rwcap is formatted as: - # pack("16ss32s", iv, AES(H(writekey+iv), plaintextrwcap), mac) - assert isinstance(data, str) - # an empty directory is serialized as an empty string - if data == "": - return {} - mutable = self.is_mutable() - children = {} - while len(data) > 0: - entry, data = split_netstring(data, 1, True) - name, rocap, rwcapdata, metadata_s = split_netstring(entry, 4) - if mutable: - rwcap = self._decrypt_rwcapdata(rwcapdata) - child = self._create_node(rwcap) - else: - child = self._create_node(rocap) - metadata = simplejson.loads(metadata_s) - assert isinstance(metadata, dict) - children[name] = (child, metadata) - return children - - def _pack_contents(self, children): - # expects children in the same format as _unpack_contents - assert isinstance(children, dict) - entries = [] - for name in sorted(children.keys()): - child, metadata = children[name] - assert (IFileNode.providedBy(child) - or IMutableFileNode.providedBy(child) - or IDirectoryNode.providedBy(child)) - assert isinstance(metadata, dict) - rwcap = child.get_uri() # might be RO if the child is not mutable - rocap = child.get_readonly() - entry = "".join([netstring(name), - netstring(rocap), - netstring(self._encrypt_rwcap(rwcap)), - netstring(simplejson.dumps(metadata))]) - entries.append(netstring(entry)) - return "".join(entries) - - def is_readonly(self): - return self._node.is_readonly() - def is_mutable(self): - return self._node.is_mutable() - - def get_uri(self): - return self._uri.to_string() - - def get_readonly(self): - return self._uri.get_readonly().to_string() - - def get_immutable_uri(self): - return self._uri.get_readonly().to_string() - - def get_verifier(self): - return self._uri.get_verifier().to_string() - - def check(self): - """Perform a file check. See IChecker.check for details.""" - pass # TODO - - def list(self): - """I return a Deferred that fires with a dictionary mapping child - name to an IFileNode or IDirectoryNode.""" - return self._read() - - def has_child(self, name): - """I return a Deferred that fires with a boolean, True if there - exists a child of the given name, False if not.""" - d = self._read() - d.addCallback(lambda children: children.has_key(name)) - return d - - def get(self, name): - """I return a Deferred that fires with a specific named child node, - either an IFileNode or an IDirectoryNode.""" - d = self._read() - d.addCallback(lambda children: children[name][0]) - return d - - def get_metadata_for(self, name): - d = self._read() - d.addCallback(lambda children: children[name][1]) - return d - - def get_child_at_path(self, path): - """Transform a child path into an IDirectoryNode or IFileNode. - - I perform a recursive series of 'get' operations to find the named - descendant node. I return a Deferred that fires with the node, or - errbacks with IndexError if the node could not be found. - - The path can be either a single string (slash-separated) or a list of - path-name elements. - """ - - if not path: - return defer.succeed(self) - if isinstance(path, (str, unicode)): - path = path.split("/") - childname = path[0] - remaining_path = path[1:] - d = self.get(childname) - if remaining_path: - def _got(node): - return node.get_child_at_path(remaining_path) - d.addCallback(_got) - return d - - def set_uri(self, name, child_uri, metadata={}): - """I add a child (by URI) at the specific name. I return a Deferred - that fires when the operation finishes. I will replace any existing - child of the same name. - - The child_uri could be for a file, or for a directory (either - read-write or read-only, using a URI that came from get_uri() ). - - If this directory node is read-only, the Deferred will errback with a - NotMutableError.""" - return self.set_node(name, self._create_node(child_uri), metadata) - - def set_node(self, name, child, metadata={}): - """I add a child at the specific name. I return a Deferred that fires - when the operation finishes. This Deferred will fire with the child - node that was just added. I will replace any existing child of the - same name. - - If this directory node is read-only, the Deferred will errback with a - NotMutableError.""" - if self.is_readonly(): - return defer.fail(NotMutableError()) - d = self._read() - def _add(children): - children[name] = (child, metadata) - new_contents = self._pack_contents(children) - return self._node.replace(new_contents) - d.addCallback(_add) - d.addCallback(lambda res: None) - return d - - def add_file(self, name, uploadable): - """I upload a file (using the given IUploadable), then attach the - resulting FileNode to the directory at the given name. I return a - Deferred that fires (with the IFileNode of the uploaded file) when - the operation completes.""" - if self.is_readonly(): - return defer.fail(NotMutableError()) - uploader = self._client.getServiceNamed("uploader") - d = uploader.upload(uploadable) - d.addCallback(lambda uri: self.set_node(name, - FileNode(uri, self._client))) - return d - - def delete(self, name): - """I remove the child at the specific name. I return a Deferred that - fires (with the node just removed) when the operation finishes.""" - if self.is_readonly(): - return defer.fail(NotMutableError()) - d = self._read() - def _delete(children): - old_child, metadata = children[name] - del children[name] - new_contents = self._pack_contents(children) - d = self._node.replace(new_contents) - def _done(res): - return old_child - d.addCallback(_done) - return d - d.addCallback(_delete) - return d - - def create_empty_directory(self, name): - """I create and attach an empty directory at the given name. I return - a Deferred that fires (with the new directory node) when the - operation finishes.""" - if self.is_readonly(): - return defer.fail(NotMutableError()) - d = self._client.create_empty_dirnode() - def _created(child): - d = self.set_node(name, child) - d.addCallback(lambda res: child) - return d - d.addCallback(_created) - return d - - def move_child_to(self, current_child_name, new_parent, - new_child_name=None): - """I take one of my children and move them to a new parent. The child - is referenced by name. On the new parent, the child will live under - 'new_child_name', which defaults to 'current_child_name'. I return a - Deferred that fires when the operation finishes.""" - if self.is_readonly() or new_parent.is_readonly(): - return defer.fail(NotMutableError()) - if new_child_name is None: - new_child_name = current_child_name - d = self.get(current_child_name) - d.addCallback(lambda child: new_parent.set_node(new_child_name, child)) - d.addCallback(lambda child: self.delete(current_child_name)) - return d - - def build_manifest(self): - """Return a frozenset of verifier-capability strings for all nodes - (directories and files) reachable from this one.""" - - # this is just a tree-walker, except that following each edge - # requires a Deferred. - - manifest = set() - manifest.add(self.get_verifier()) - - d = self._build_manifest_from_node(self, manifest) - def _done(res): - # LIT nodes have no verifier-capability: their data is stored - # inside the URI itself, so there is no need to refresh anything. - # They indicate this by returning None from their get_verifier - # method. We need to remove any such Nones from our set. We also - # want to convert all these caps into strings. - return frozenset([IVerifierURI(cap).to_string() - for cap in manifest - if cap is not None]) - d.addCallback(_done) - return d - - def _build_manifest_from_node(self, node, manifest): - d = node.list() - def _got_list(res): - dl = [] - for name, (child, metadata) in res.iteritems(): - verifier = child.get_verifier() - if verifier not in manifest: - manifest.add(verifier) - if IDirectoryNode.providedBy(child): - dl.append(self._build_manifest_from_node(child, - manifest)) - if dl: - return defer.DeferredList(dl) - d.addCallback(_got_list) - return d - -# use client.create_dirnode() to make one of these - diff --git a/src/allmydata/test/test_mutable.py b/src/allmydata/test/test_mutable.py index d7d78f4c..186112af 100644 --- a/src/allmydata/test/test_mutable.py +++ b/src/allmydata/test/test_mutable.py @@ -3,8 +3,8 @@ import itertools from twisted.trial import unittest from twisted.internet import defer -from allmydata import mutable, uri -from allmydata.mutable import split_netstring +from allmydata import mutable, uri, dirnode2 +from allmydata.dirnode2 import split_netstring from allmydata.util.hashutil import netstring class Netstring(unittest.TestCase): @@ -62,7 +62,7 @@ class FakeFilenode(mutable.MutableFileNode): def get_readonly(self): return "fake readonly" -class FakeNewDirectoryNode(mutable.NewDirectoryNode): +class FakeNewDirectoryNode(dirnode2.NewDirectoryNode): filenode_class = FakeFilenode class MyClient: