# Copyright (C) 2006-2010 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""Infrastructure for server-side request handlers.
Interesting module attributes:
* The request_handlers registry maps verb names to SmartServerRequest
classes.
* The jail_info threading.local() object is used to prevent accidental
opening of BzrDirs outside of the backing transport, or any other
transports placed in jail_info.transports. The jail_info is reset on
every call into a request handler (which can happen an arbitrary number
of times during a request).
"""
# XXX: The class names are a little confusing: the protocol will instantiate a
# SmartServerRequestHandler, whose dispatch_command method creates an instance
# of a SmartServerRequest subclass.
import tempfile
import thread
import threading
from bzrlib import (
bzrdir,
debug,
errors,
osutils,
registry,
revision,
trace,
urlutils,
)
from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
from bzrlib.bundle import serializer
""")
jail_info = threading.local()
jail_info.transports = None
def _install_hook():
bzrdir.BzrDir.hooks.install_named_hook(
'pre_open', _pre_open_hook, 'checking server jail')
def _pre_open_hook(transport):
allowed_transports = getattr(jail_info, 'transports', None)
if allowed_transports is None:
return
abspath = transport.base
for allowed_transport in allowed_transports:
try:
allowed_transport.relpath(abspath)
except errors.PathNotChild:
continue
else:
return
raise errors.JailBreak(abspath)
_install_hook()
class SmartServerRequest(object):
"""Base class for request handlers.
To define a new request, subclass this class and override the `do` method
(and if appropriate, `do_body` as well). Request implementors should take
care to call `translate_client_path` and `transport_from_client_path` as
appropriate when dealing with paths received from the client.
"""
# XXX: rename this class to BaseSmartServerRequestHandler ? A request
# *handler* is a different concept to the request.
def __init__(self, backing_transport, root_client_path='/', jail_root=None):
"""Constructor.
:param backing_transport: the base transport to be used when performing
this request.
:param root_client_path: the client path that maps to the root of
backing_transport. This is used to interpret relpaths received
from the client. Clients will not be able to refer to paths above
this root. If root_client_path is None, then no translation will
be performed on client paths. Default is '/'.
:param jail_root: if specified, the root of the BzrDir.open jail to use
instead of backing_transport.
"""
self._backing_transport = backing_transport
if jail_root is None:
jail_root = backing_transport
self._jail_root = jail_root
if root_client_path is not None:
if not root_client_path.startswith('/'):
root_client_path = '/' + root_client_path
if not root_client_path.endswith('/'):
root_client_path += '/'
self._root_client_path = root_client_path
self._body_chunks = []
def _check_enabled(self):
"""Raises DisabledMethod if this method is disabled."""
pass
def do(self, *args):
"""Mandatory extension point for SmartServerRequest subclasses.
Subclasses must implement this.
This should return a SmartServerResponse if this command expects to
receive no body.
"""
raise NotImplementedError(self.do)
def execute(self, *args):
"""Public entry point to execute this request.
It will return a SmartServerResponse if the command does not expect a
body.
:param *args: the arguments of the request.
"""
self._check_enabled()
return self.do(*args)
def do_body(self, body_bytes):
"""Called if the client sends a body with the request.
The do() method is still called, and must have returned None.
Must return a SmartServerResponse.
"""
if body_bytes != '':
raise errors.SmartProtocolError('Request does not expect a body')
def do_chunk(self, chunk_bytes):
"""Called with each body chunk if the request has a streamed body.
The do() method is still called, and must have returned None.
"""
self._body_chunks.append(chunk_bytes)
def do_end(self):
"""Called when the end of the request has been received."""
body_bytes = ''.join(self._body_chunks)
self._body_chunks = None
return self.do_body(body_bytes)
def setup_jail(self):
jail_info.transports = [self._jail_root]
def teardown_jail(self):
jail_info.transports = None
def translate_client_path(self, client_path):
"""Translate a path received from a network client into a local
relpath.
All paths received from the client *must* be translated.
:param client_path: the path from the client.
:returns: a relpath that may be used with self._backing_transport
(unlike the untranslated client_path, which must not be used with
the backing transport).
"""
if self._root_client_path is None:
# no translation necessary!
return client_path
if not client_path.startswith('/'):
client_path = '/' + client_path
if client_path + '/' == self._root_client_path:
return '.'
if client_path.startswith(self._root_client_path):
path = client_path[len(self._root_client_path):]
relpath = urlutils.joinpath('/', path)
if not relpath.startswith('/'):
raise ValueError(relpath)
return urlutils.escape('.' + relpath)
else:
raise errors.PathNotChild(client_path, self._root_client_path)
def transport_from_client_path(self, client_path):
"""Get a backing transport corresponding to the location referred to by
a network client.
:seealso: translate_client_path
:returns: a transport cloned from self._backing_transport
"""
relpath = self.translate_client_path(client_path)
return self._backing_transport.clone(relpath)
class SmartServerResponse(object):
"""A response to a client request.
This base class should not be used. Instead use
SuccessfulSmartServerResponse and FailedSmartServerResponse as appropriate.
"""
def __init__(self, args, body=None, body_stream=None):
"""Constructor.
:param args: tuple of response arguments.
:param body: string of a response body.
:param body_stream: iterable of bytestrings to be streamed to the
client.
"""
self.args = args
if body is not None and body_stream is not None:
raise errors.BzrError(
"'body' and 'body_stream' are mutually exclusive.")
self.body = body
self.body_stream = body_stream
def __eq__(self, other):
if other is None:
return False
return (other.args == self.args and
other.body == self.body and
other.body_stream is self.body_stream)
def __repr__(self):
return "<%s args=%r body=%r>" % (self.__class__.__name__,
self.args, self.body)
class FailedSmartServerResponse(SmartServerResponse):
"""A SmartServerResponse for a request which failed."""
def is_successful(self):
"""FailedSmartServerResponse are not successful."""
return False
class SuccessfulSmartServerResponse(SmartServerResponse):
"""A SmartServerResponse for a successfully completed request."""
def is_successful(self):
"""SuccessfulSmartServerResponse are successful."""
return True
class SmartServerRequestHandler(object):
"""Protocol logic for smart server.
This doesn't handle serialization at all, it just processes requests and
creates responses.
"""
# IMPORTANT FOR IMPLEMENTORS: It is important that SmartServerRequestHandler
# not contain encoding or decoding logic to allow the wire protocol to vary
# from the object protocol: we will want to tweak the wire protocol separate
# from the object model, and ideally we will be able to do that without
# having a SmartServerRequestHandler subclass for each wire protocol, rather
# just a Protocol subclass.
# TODO: Better way of representing the body for commands that take it,
# and allow it to be streamed into the server.
def __init__(self, backing_transport, commands, root_client_path,
jail_root=None):
"""Constructor.
:param backing_transport: a Transport to handle requests for.
:param commands: a registry mapping command names to SmartServerRequest
subclasses. e.g. bzrlib.transport.smart.vfs.vfs_commands.
"""
self._backing_transport = backing_transport
self._root_client_path = root_client_path
self._commands = commands
if jail_root is None:
jail_root = backing_transport
self._jail_root = jail_root
self.response = None
self.finished_reading = False
self._command = None
if 'hpss' in debug.debug_flags:
self._request_start_time = osutils.timer_func()
self._thread_id = thread.get_ident()
def _trace(self, action, message, extra_bytes=None, include_time=False):
# It is a bit of a shame that this functionality overlaps with that of
# ProtocolThreeRequester._trace. However, there is enough difference
# that just putting it in a helper doesn't help a lot. And some state
# is taken from the instance.
if include_time:
t = '%5.3fs ' % (osutils.timer_func() - self._request_start_time)
else:
t = ''
if extra_bytes is None:
extra = ''
else:
extra = ' ' + repr(extra_bytes[:40])
if len(extra) > 33:
extra = extra[:29] + extra[-1] + '...'
trace.mutter('%12s: [%s] %s%s%s'
% (action, self._thread_id, t, message, extra))
def accept_body(self, bytes):
"""Accept body data."""
if self._command is None:
# no active command object, so ignore the event.
return
self._run_handler_code(self._command.do_chunk, (bytes,), {})
if 'hpss' in debug.debug_flags:
self._trace('accept body',
'%d bytes' % (len(bytes),), bytes)
def end_of_body(self):
"""No more body data will be received."""
self._run_handler_code(self._command.do_end, (), {})
# cannot read after this.
self.finished_reading = True
if 'hpss' in debug.debug_flags:
self._trace('end of body', '', include_time=True)
def _run_handler_code(self, callable, args, kwargs):
"""Run some handler specific code 'callable'.
If a result is returned, it is considered to be the commands response,
and finished_reading is set true, and its assigned to self.response.
Any exceptions caught are translated and a response object created
from them.
"""
result = self._call_converting_errors(callable, args, kwargs)
if result is not None:
self.response = result
self.finished_reading = True
def _call_converting_errors(self, callable, args, kwargs):
"""Call callable converting errors to Response objects."""
# XXX: most of this error conversion is VFS-related, and thus ought to
# be in SmartServerVFSRequestHandler somewhere.
try:
self._command.setup_jail()
try:
return callable(*args, **kwargs)
finally:
self._command.teardown_jail()
except (KeyboardInterrupt, SystemExit):
raise
except Exception, err:
err_struct = _translate_error(err)
return FailedSmartServerResponse(err_struct)
def headers_received(self, headers):
# Just a no-op at the moment.
if 'hpss' in debug.debug_flags:
self._trace('headers', repr(headers))
def args_received(self, args):
cmd = args[0]
args = args[1:]
try:
command = self._commands.get(cmd)
except LookupError:
if 'hpss' in debug.debug_flags:
self._trace('hpss unknown request',
cmd, repr(args)[1:-1])
raise errors.UnknownSmartMethod(cmd)
if 'hpss' in debug.debug_flags:
from bzrlib.smart import vfs
if issubclass(command, vfs.VfsRequest):
action = 'hpss vfs req'
else:
action = 'hpss request'
self._trace(action,
'%s %s' % (cmd, repr(args)[1:-1]))
self._command = command(
self._backing_transport, self._root_client_path, self._jail_root)
self._run_handler_code(self._command.execute, args, {})
def end_received(self):
if self._command is None:
# no active command object, so ignore the event.
return
self._run_handler_code(self._command.do_end, (), {})
if 'hpss' in debug.debug_flags:
self._trace('end', '', include_time=True)
def post_body_error_received(self, error_args):
# Just a no-op at the moment.
pass
def _translate_error(err):
if isinstance(err, errors.NoSuchFile):
return ('NoSuchFile', err.path)
elif isinstance(err, errors.FileExists):
return ('FileExists', err.path)
elif isinstance(err, errors.DirectoryNotEmpty):
return ('DirectoryNotEmpty', err.path)
elif isinstance(err, errors.IncompatibleRepositories):
return ('IncompatibleRepositories', str(err.source), str(err.target),
str(err.details))
elif isinstance(err, errors.ShortReadvError):
return ('ShortReadvError', err.path, str(err.offset), str(err.length),
str(err.actual))
elif isinstance(err, errors.UnstackableRepositoryFormat):
return (('UnstackableRepositoryFormat', str(err.format), err.url))
elif isinstance(err, errors.UnstackableBranchFormat):
return ('UnstackableBranchFormat', str(err.format), err.url)
elif isinstance(err, errors.NotStacked):
return ('NotStacked',)
elif isinstance(err, UnicodeError):
# If it is a DecodeError, than most likely we are starting
# with a plain string
str_or_unicode = err.object
if isinstance(str_or_unicode, unicode):
# XXX: UTF-8 might have \x01 (our protocol v1 and v2 seperator
# byte) in it, so this encoding could cause broken responses.
# Newer clients use protocol v3, so will be fine.
val = 'u:' + str_or_unicode.encode('utf-8')
else:
val = 's:' + str_or_unicode.encode('base64')
# This handles UnicodeEncodeError or UnicodeDecodeError
return (err.__class__.__name__, err.encoding, val, str(err.start),
str(err.end), err.reason)
elif isinstance(err, errors.TransportNotPossible):
if err.msg == "readonly transport":
return ('ReadOnlyError', )
elif isinstance(err, errors.ReadError):
# cannot read the file
return ('ReadError', err.path)
elif isinstance(err, errors.PermissionDenied):
return ('PermissionDenied', err.path, err.extra)
elif isinstance(err, errors.TokenMismatch):
return ('TokenMismatch', err.given_token, err.lock_token)
elif isinstance(err, errors.LockContention):
return ('LockContention',)
# Unserialisable error. Log it, and return a generic error
trace.log_exception_quietly()
return ('error', str(err))
class HelloRequest(SmartServerRequest):
"""Answer a version request with the highest protocol version this server
supports.
"""
def do(self):
return SuccessfulSmartServerResponse(('ok', '2'))
class GetBundleRequest(SmartServerRequest):
"""Get a bundle of from the null revision to the specified revision."""
def do(self, path, revision_id):
# open transport relative to our base
t = self.transport_from_client_path(path)
control, extra_path = bzrdir.BzrDir.open_containing_from_transport(t)
repo = control.open_repository()
tmpf = tempfile.TemporaryFile()
base_revision = revision.NULL_REVISION
serializer.write_bundle(repo, revision_id, base_revision, tmpf)
tmpf.seek(0)
return SuccessfulSmartServerResponse((), tmpf.read())
class SmartServerIsReadonly(SmartServerRequest):
# XXX: this request method belongs somewhere else.
def do(self):
if self._backing_transport.is_readonly():
answer = 'yes'
else:
answer = 'no'
return SuccessfulSmartServerResponse((answer,))
request_handlers = registry.Registry()
request_handlers.register_lazy(
'append', 'bzrlib.smart.vfs', 'AppendRequest')
request_handlers.register_lazy(
'Branch.get_config_file', 'bzrlib.smart.branch',
'SmartServerBranchGetConfigFile')
request_handlers.register_lazy(
'Branch.get_parent', 'bzrlib.smart.branch', 'SmartServerBranchGetParent')
request_handlers.register_lazy(
'Branch.get_tags_bytes', 'bzrlib.smart.branch',
'SmartServerBranchGetTagsBytes')
request_handlers.register_lazy(
'Branch.set_tags_bytes', 'bzrlib.smart.branch',
'SmartServerBranchSetTagsBytes')
request_handlers.register_lazy(
'Branch.get_stacked_on_url', 'bzrlib.smart.branch', 'SmartServerBranchRequestGetStackedOnURL')
request_handlers.register_lazy(
'Branch.last_revision_info', 'bzrlib.smart.branch', 'SmartServerBranchRequestLastRevisionInfo')
request_handlers.register_lazy(
'Branch.lock_write', 'bzrlib.smart.branch', 'SmartServerBranchRequestLockWrite')
request_handlers.register_lazy( 'Branch.revision_history',
'bzrlib.smart.branch', 'SmartServerRequestRevisionHistory')
request_handlers.register_lazy( 'Branch.set_config_option',
'bzrlib.smart.branch', 'SmartServerBranchRequestSetConfigOption')
request_handlers.register_lazy( 'Branch.set_config_option_dict',
'bzrlib.smart.branch', 'SmartServerBranchRequestSetConfigOptionDict')
request_handlers.register_lazy( 'Branch.set_last_revision',
'bzrlib.smart.branch', 'SmartServerBranchRequestSetLastRevision')
request_handlers.register_lazy(
'Branch.set_last_revision_info', 'bzrlib.smart.branch',
'SmartServerBranchRequestSetLastRevisionInfo')
request_handlers.register_lazy(
'Branch.set_last_revision_ex', 'bzrlib.smart.branch',
'SmartServerBranchRequestSetLastRevisionEx')
request_handlers.register_lazy(
'Branch.set_parent_location', 'bzrlib.smart.branch',
'SmartServerBranchRequestSetParentLocation')
request_handlers.register_lazy(
'Branch.unlock', 'bzrlib.smart.branch', 'SmartServerBranchRequestUnlock')
request_handlers.register_lazy(
'BzrDir.cloning_metadir', 'bzrlib.smart.bzrdir',
'SmartServerBzrDirRequestCloningMetaDir')
request_handlers.register_lazy(
'BzrDir.create_branch', 'bzrlib.smart.bzrdir',
'SmartServerRequestCreateBranch')
request_handlers.register_lazy(
'BzrDir.create_repository', 'bzrlib.smart.bzrdir',
'SmartServerRequestCreateRepository')
request_handlers.register_lazy(
'BzrDir.find_repository', 'bzrlib.smart.bzrdir',
'SmartServerRequestFindRepositoryV1')
request_handlers.register_lazy(
'BzrDir.find_repositoryV2', 'bzrlib.smart.bzrdir',
'SmartServerRequestFindRepositoryV2')
request_handlers.register_lazy(
'BzrDir.find_repositoryV3', 'bzrlib.smart.bzrdir',
'SmartServerRequestFindRepositoryV3')
request_handlers.register_lazy(
'BzrDir.get_config_file', 'bzrlib.smart.bzrdir',
'SmartServerBzrDirRequestConfigFile')
request_handlers.register_lazy(
'BzrDirFormat.initialize', 'bzrlib.smart.bzrdir',
'SmartServerRequestInitializeBzrDir')
request_handlers.register_lazy(
'BzrDirFormat.initialize_ex_1.16', 'bzrlib.smart.bzrdir',
'SmartServerRequestBzrDirInitializeEx')
request_handlers.register_lazy(
'BzrDir.open', 'bzrlib.smart.bzrdir', 'SmartServerRequestOpenBzrDir')
request_handlers.register_lazy(
'BzrDir.open_2.1', 'bzrlib.smart.bzrdir', 'SmartServerRequestOpenBzrDir_2_1')
request_handlers.register_lazy(
'BzrDir.open_branch', 'bzrlib.smart.bzrdir',
'SmartServerRequestOpenBranch')
request_handlers.register_lazy(
'BzrDir.open_branchV2', 'bzrlib.smart.bzrdir',
'SmartServerRequestOpenBranchV2')
request_handlers.register_lazy(
'BzrDir.open_branchV3', 'bzrlib.smart.bzrdir',
'SmartServerRequestOpenBranchV3')
request_handlers.register_lazy(
'delete', 'bzrlib.smart.vfs', 'DeleteRequest')
request_handlers.register_lazy(
'get', 'bzrlib.smart.vfs', 'GetRequest')
request_handlers.register_lazy(
'get_bundle', 'bzrlib.smart.request', 'GetBundleRequest')
request_handlers.register_lazy(
'has', 'bzrlib.smart.vfs', 'HasRequest')
request_handlers.register_lazy(
'hello', 'bzrlib.smart.request', 'HelloRequest')
request_handlers.register_lazy(
'iter_files_recursive', 'bzrlib.smart.vfs', 'IterFilesRecursiveRequest')
request_handlers.register_lazy(
'list_dir', 'bzrlib.smart.vfs', 'ListDirRequest')
request_handlers.register_lazy(
'mkdir', 'bzrlib.smart.vfs', 'MkdirRequest')
request_handlers.register_lazy(
'move', 'bzrlib.smart.vfs', 'MoveRequest')
request_handlers.register_lazy(
'put', 'bzrlib.smart.vfs', 'PutRequest')
request_handlers.register_lazy(
'put_non_atomic', 'bzrlib.smart.vfs', 'PutNonAtomicRequest')
request_handlers.register_lazy(
'readv', 'bzrlib.smart.vfs', 'ReadvRequest')
request_handlers.register_lazy(
'rename', 'bzrlib.smart.vfs', 'RenameRequest')
request_handlers.register_lazy(
'PackRepository.autopack', 'bzrlib.smart.packrepository',
'SmartServerPackRepositoryAutopack')
request_handlers.register_lazy('Repository.gather_stats',
'bzrlib.smart.repository',
'SmartServerRepositoryGatherStats')
request_handlers.register_lazy('Repository.get_parent_map',
'bzrlib.smart.repository',
'SmartServerRepositoryGetParentMap')
request_handlers.register_lazy(
'Repository.get_revision_graph', 'bzrlib.smart.repository', 'SmartServerRepositoryGetRevisionGraph')
request_handlers.register_lazy(
'Repository.has_revision', 'bzrlib.smart.repository', 'SmartServerRequestHasRevision')
request_handlers.register_lazy(
'Repository.insert_stream', 'bzrlib.smart.repository', 'SmartServerRepositoryInsertStream')
request_handlers.register_lazy(
'Repository.insert_stream_1.19', 'bzrlib.smart.repository', 'SmartServerRepositoryInsertStream_1_19')
request_handlers.register_lazy(
'Repository.insert_stream_locked', 'bzrlib.smart.repository', 'SmartServerRepositoryInsertStreamLocked')
request_handlers.register_lazy(
'Repository.is_shared', 'bzrlib.smart.repository', 'SmartServerRepositoryIsShared')
request_handlers.register_lazy(
'Repository.lock_write', 'bzrlib.smart.repository', 'SmartServerRepositoryLockWrite')
request_handlers.register_lazy(
'Repository.set_make_working_trees', 'bzrlib.smart.repository',
'SmartServerRepositorySetMakeWorkingTrees')
request_handlers.register_lazy(
'Repository.unlock', 'bzrlib.smart.repository', 'SmartServerRepositoryUnlock')
request_handlers.register_lazy(
'Repository.get_rev_id_for_revno', 'bzrlib.smart.repository',
'SmartServerRepositoryGetRevIdForRevno')
request_handlers.register_lazy(
'Repository.get_stream', 'bzrlib.smart.repository',
'SmartServerRepositoryGetStream')
request_handlers.register_lazy(
'Repository.get_stream_1.19', 'bzrlib.smart.repository',
'SmartServerRepositoryGetStream_1_19')
request_handlers.register_lazy(
'Repository.tarball', 'bzrlib.smart.repository',
'SmartServerRepositoryTarball')
request_handlers.register_lazy(
'rmdir', 'bzrlib.smart.vfs', 'RmdirRequest')
request_handlers.register_lazy(
'stat', 'bzrlib.smart.vfs', 'StatRequest')
request_handlers.register_lazy(
'Transport.is_readonly', 'bzrlib.smart.request', 'SmartServerIsReadonly')
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