diff options
Diffstat (limited to 'src/leap/soledad/common/l2db/remote/http_app.py')
| -rw-r--r-- | src/leap/soledad/common/l2db/remote/http_app.py | 660 |
1 files changed, 660 insertions, 0 deletions
diff --git a/src/leap/soledad/common/l2db/remote/http_app.py b/src/leap/soledad/common/l2db/remote/http_app.py new file mode 100644 index 00000000..a4eddb36 --- /dev/null +++ b/src/leap/soledad/common/l2db/remote/http_app.py @@ -0,0 +1,660 @@ +# Copyright 2011-2012 Canonical Ltd. +# Copyright 2016 LEAP Encryption Access Project +# +# This file is part of u1db. +# +# u1db is free software: you can redistribute it and/or modify +# it under the terms of the GNU Lesser General Public License version 3 +# as published by the Free Software Foundation. +# +# u1db 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 Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with u1db. If not, see <http://www.gnu.org/licenses/>. + +""" +HTTP Application exposing U1DB. +""" +# TODO -- deprecate, use twisted/txaio. + +import functools +import six.moves.http_client as httplib +import inspect +import json +import sys +import six.moves.urllib.parse as urlparse + +import routes.mapper + +from leap.soledad.common.l2db import ( + __version__ as _u1db_version, + DBNAME_CONSTRAINTS, Document, + errors, sync) +from leap.soledad.common.l2db.remote import http_errors, utils + + +def parse_bool(expression): + """Parse boolean querystring parameter.""" + if expression == 'true': + return True + return False + + +def parse_list(expression): + if not expression: + return [] + return [t.strip() for t in expression.split(',')] + + +def none_or_str(expression): + if expression is None: + return None + return str(expression) + + +class BadRequest(Exception): + """Bad request.""" + + +class _FencedReader(object): + """Read and get lines from a file but not past a given length.""" + + MAXCHUNK = 8192 + + def __init__(self, rfile, total, max_entry_size): + self.rfile = rfile + self.remaining = total + self.max_entry_size = max_entry_size + self._kept = None + + def read_chunk(self, atmost): + if self._kept is not None: + # ignore atmost, kept data should be a subchunk anyway + kept, self._kept = self._kept, None + return kept + if self.remaining == 0: + return '' + data = self.rfile.read(min(self.remaining, atmost)) + self.remaining -= len(data) + return data + + def getline(self): + line_parts = [] + size = 0 + while True: + chunk = self.read_chunk(self.MAXCHUNK) + if chunk == '': + break + nl = chunk.find("\n") + if nl != -1: + size += nl + 1 + if size > self.max_entry_size: + raise BadRequest + line_parts.append(chunk[:nl + 1]) + rest = chunk[nl + 1:] + self._kept = rest or None + break + else: + size += len(chunk) + if size > self.max_entry_size: + raise BadRequest + line_parts.append(chunk) + return ''.join(line_parts) + + +def http_method(**control): + """Decoration for handling of query arguments and content for a HTTP + method. + + args and content here are the query arguments and body of the incoming + HTTP requests. + + Match query arguments to python method arguments: + w = http_method()(f) + w(self, args, content) => args["content"]=content; + f(self, **args) + + JSON deserialize content to arguments: + w = http_method(content_as_args=True,...)(f) + w(self, args, content) => args.update(json.loads(content)); + f(self, **args) + + Support conversions (e.g int): + w = http_method(Arg=Conv,...)(f) + w(self, args, content) => args["Arg"]=Conv(args["Arg"]); + f(self, **args) + + Enforce no use of query arguments: + w = http_method(no_query=True,...)(f) + w(self, args, content) raises BadRequest if args is not empty + + Argument mismatches, deserialisation failures produce BadRequest. + """ + content_as_args = control.pop('content_as_args', False) + no_query = control.pop('no_query', False) + conversions = control.items() + + def wrap(f): + argspec = inspect.getargspec(f) + assert argspec.args[0] == "self" + nargs = len(argspec.args) + ndefaults = len(argspec.defaults or ()) + required_args = set(argspec.args[1:nargs - ndefaults]) + all_args = set(argspec.args) + + @functools.wraps(f) + def wrapper(self, args, content): + if no_query and args: + raise BadRequest() + if content is not None: + if content_as_args: + try: + args.update(json.loads(content)) + except ValueError: + raise BadRequest() + else: + args["content"] = content + if not (required_args <= set(args) <= all_args): + raise BadRequest("Missing required arguments.") + for name, conv in conversions: + if name not in args: + continue + try: + args[name] = conv(args[name]) + except ValueError: + raise BadRequest() + return f(self, **args) + + return wrapper + + return wrap + + +class URLToResource(object): + """Mappings from URLs to resources.""" + + def __init__(self): + self._map = routes.mapper.Mapper(controller_scan=None) + + def register(self, resource_cls): + # register + self._map.connect(None, resource_cls.url_pattern, + resource_cls=resource_cls, + requirements={"dbname": DBNAME_CONSTRAINTS}) + self._map.create_regs() + return resource_cls + + def match(self, path): + params = self._map.match(path) + if params is None: + return None, None + resource_cls = params.pop('resource_cls') + return resource_cls, params + + +url_to_resource = URLToResource() + + +@url_to_resource.register +class GlobalResource(object): + """Global (root) resource.""" + + url_pattern = "/" + + def __init__(self, state, responder): + self.state = state + self.responder = responder + + @http_method() + def get(self): + info = self.state.global_info() + info['version'] = _u1db_version + self.responder.send_response_json(**info) + + +@url_to_resource.register +class DatabaseResource(object): + """Database resource.""" + + url_pattern = "/{dbname}" + + def __init__(self, dbname, state, responder): + self.dbname = dbname + self.state = state + self.responder = responder + + @http_method() + def get(self): + self.state.check_database(self.dbname) + self.responder.send_response_json(200) + + @http_method(content_as_args=True) + def put(self): + self.state.ensure_database(self.dbname) + self.responder.send_response_json(200, ok=True) + + @http_method() + def delete(self): + self.state.delete_database(self.dbname) + self.responder.send_response_json(200, ok=True) + + +@url_to_resource.register +class DocsResource(object): + """Documents resource.""" + + url_pattern = "/{dbname}/docs" + + def __init__(self, dbname, state, responder): + self.responder = responder + self.db = state.open_database(dbname) + + @http_method(doc_ids=parse_list, check_for_conflicts=parse_bool, + include_deleted=parse_bool) + def get(self, doc_ids=None, check_for_conflicts=True, + include_deleted=False): + if doc_ids is None: + raise errors.MissingDocIds + docs = self.db.get_docs(doc_ids, include_deleted=include_deleted) + self.responder.content_type = 'application/json' + self.responder.start_response(200) + self.responder.start_stream(), + for doc in docs: + entry = dict( + doc_id=doc.doc_id, doc_rev=doc.rev, content=doc.get_json(), + has_conflicts=doc.has_conflicts) + self.responder.stream_entry(entry) + self.responder.end_stream() + self.responder.finish_response() + + +@url_to_resource.register +class AllDocsResource(object): + """All Documents resource.""" + + url_pattern = "/{dbname}/all-docs" + + def __init__(self, dbname, state, responder): + self.responder = responder + self.db = state.open_database(dbname) + + @http_method(include_deleted=parse_bool) + def get(self, include_deleted=False): + gen, docs = self.db.get_all_docs(include_deleted=include_deleted) + self.responder.content_type = 'application/json' + # returning a x-u1db-generation header is optional + # HTTPDatabase will fallback to return -1 if it's missing + self.responder.start_response(200, + headers={'x-u1db-generation': str(gen)}) + self.responder.start_stream(), + for doc in docs: + entry = dict( + doc_id=doc.doc_id, doc_rev=doc.rev, content=doc.get_json(), + has_conflicts=doc.has_conflicts) + self.responder.stream_entry(entry) + self.responder.end_stream() + self.responder.finish_response() + + +@url_to_resource.register +class DocResource(object): + """Document resource.""" + + url_pattern = "/{dbname}/doc/{id:.*}" + + def __init__(self, dbname, id, state, responder): + self.id = id + self.responder = responder + self.db = state.open_database(dbname) + + @http_method(old_rev=str) + def put(self, content, old_rev=None): + doc = Document(self.id, old_rev, content) + doc_rev = self.db.put_doc(doc) + if old_rev is None: + status = 201 # created + else: + status = 200 + self.responder.send_response_json(status, rev=doc_rev) + + @http_method(old_rev=str) + def delete(self, old_rev=None): + doc = Document(self.id, old_rev, None) + self.db.delete_doc(doc) + self.responder.send_response_json(200, rev=doc.rev) + + @http_method(include_deleted=parse_bool) + def get(self, include_deleted=False): + doc = self.db.get_doc(self.id, include_deleted=include_deleted) + if doc is None: + wire_descr = errors.DocumentDoesNotExist.wire_description + self.responder.send_response_json( + http_errors.wire_description_to_status[wire_descr], + error=wire_descr, + headers={ + 'x-u1db-rev': '', + 'x-u1db-has-conflicts': 'false' + }) + return + headers = { + 'x-u1db-rev': doc.rev, + 'x-u1db-has-conflicts': json.dumps(doc.has_conflicts) + } + if doc.is_tombstone(): + self.responder.send_response_json( + http_errors.wire_description_to_status[ + errors.DOCUMENT_DELETED], + error=errors.DOCUMENT_DELETED, + headers=headers) + else: + self.responder.send_response_content( + doc.get_json(), headers=headers) + + +@url_to_resource.register +class SyncResource(object): + """Sync endpoint resource.""" + + # maximum allowed request body size + max_request_size = 15 * 1024 * 1024 # 15Mb + # maximum allowed entry/line size in request body + max_entry_size = 10 * 1024 * 1024 # 10Mb + + url_pattern = "/{dbname}/sync-from/{source_replica_uid}" + + # pluggable + sync_exchange_class = sync.SyncExchange + + def __init__(self, dbname, source_replica_uid, state, responder): + self.source_replica_uid = source_replica_uid + self.responder = responder + self.state = state + self.dbname = dbname + self.replica_uid = None + + def get_target(self): + return self.state.open_database(self.dbname).get_sync_target() + + @http_method() + def get(self): + result = self.get_target().get_sync_info(self.source_replica_uid) + self.responder.send_response_json( + target_replica_uid=result[0], target_replica_generation=result[1], + target_replica_transaction_id=result[2], + source_replica_uid=self.source_replica_uid, + source_replica_generation=result[3], + source_transaction_id=result[4]) + + @http_method(generation=int, + content_as_args=True, no_query=True) + def put(self, generation, transaction_id): + self.get_target().record_sync_info(self.source_replica_uid, + generation, + transaction_id) + self.responder.send_response_json(ok=True) + + # Implements the same logic as LocalSyncTarget.sync_exchange + + @http_method(last_known_generation=int, last_known_trans_id=none_or_str, + content_as_args=True) + def post_args(self, last_known_generation, last_known_trans_id=None, + ensure=False): + if ensure: + db, self.replica_uid = self.state.ensure_database(self.dbname) + else: + db = self.state.open_database(self.dbname) + db.validate_gen_and_trans_id( + last_known_generation, last_known_trans_id) + self.sync_exch = self.sync_exchange_class( + db, self.source_replica_uid, last_known_generation) + + @http_method(content_as_args=True) + def post_stream_entry(self, id, rev, content, gen, trans_id): + doc = Document(id, rev, content) + self.sync_exch.insert_doc_from_source(doc, gen, trans_id) + + def post_end(self): + + def send_doc(doc, gen, trans_id): + entry = dict(id=doc.doc_id, rev=doc.rev, content=doc.get_json(), + gen=gen, trans_id=trans_id) + self.responder.stream_entry(entry) + + new_gen = self.sync_exch.find_changes_to_return() + self.responder.content_type = 'application/x-u1db-sync-stream' + self.responder.start_response(200) + self.responder.start_stream(), + header = {"new_generation": new_gen, + "new_transaction_id": self.sync_exch.new_trans_id} + if self.replica_uid is not None: + header['replica_uid'] = self.replica_uid + self.responder.stream_entry(header) + self.sync_exch.return_docs(send_doc) + self.responder.end_stream() + self.responder.finish_response() + + +class HTTPResponder(object): + """Encode responses from the server back to the client.""" + + # a multi document response will put args and documents + # each on one line of the response body + + def __init__(self, start_response): + self._started = False + self._stream_state = -1 + self._no_initial_obj = True + self.sent_response = False + self._start_response = start_response + self._write = None + self.content_type = 'application/json' + self.content = [] + + def start_response(self, status, obj_dic=None, headers={}): + """start sending response with optional first json object.""" + if self._started: + return + self._started = True + status_text = httplib.responses[status] + self._write = self._start_response( + '%d %s' % (status, status_text), + [('content-type', self.content_type), + ('cache-control', 'no-cache')] + + headers.items()) + # xxx version in headers + if obj_dic is not None: + self._no_initial_obj = False + self._write(json.dumps(obj_dic) + "\r\n") + + def finish_response(self): + """finish sending response.""" + self.sent_response = True + + def send_response_json(self, status=200, headers={}, **kwargs): + """send and finish response with json object body from keyword args.""" + content = json.dumps(kwargs) + "\r\n" + self.send_response_content(content, headers=headers, status=status) + + def send_response_content(self, content, status=200, headers={}): + """send and finish response with content""" + headers['content-length'] = str(len(content)) + self.start_response(status, headers=headers) + if self._stream_state == 1: + self.content = [',\r\n', content] + else: + self.content = [content] + self.finish_response() + + def start_stream(self): + "start stream (array) as part of the response." + assert self._started and self._no_initial_obj + self._stream_state = 0 + self._write("[") + + def stream_entry(self, entry): + "send stream entry as part of the response." + assert self._stream_state != -1 + if self._stream_state == 0: + self._stream_state = 1 + self._write('\r\n') + else: + self._write(',\r\n') + if type(entry) == dict: + entry = json.dumps(entry) + self._write(entry) + + def end_stream(self): + "end stream (array)." + assert self._stream_state != -1 + self._write("\r\n]\r\n") + + +class HTTPInvocationByMethodWithBody(object): + """Invoke methods on a resource.""" + + def __init__(self, resource, environ, parameters): + self.resource = resource + self.environ = environ + self.max_request_size = getattr( + resource, 'max_request_size', parameters.max_request_size) + self.max_entry_size = getattr( + resource, 'max_entry_size', parameters.max_entry_size) + + def _lookup(self, method): + try: + return getattr(self.resource, method) + except AttributeError: + raise BadRequest() + + def __call__(self): + args = urlparse.parse_qsl(self.environ['QUERY_STRING'], + strict_parsing=False) + try: + args = dict( + (k.decode('utf-8'), v.decode('utf-8')) for k, v in args) + except ValueError: + raise BadRequest() + method = self.environ['REQUEST_METHOD'].lower() + if method in ('get', 'delete'): + meth = self._lookup(method) + return meth(args, None) + else: + # we expect content-length > 0, reconsider if we move + # to support chunked enconding + try: + content_length = int(self.environ['CONTENT_LENGTH']) + except (ValueError, KeyError): + raise BadRequest + if content_length <= 0: + raise BadRequest + if content_length > self.max_request_size: + raise BadRequest + reader = _FencedReader(self.environ['wsgi.input'], content_length, + self.max_entry_size) + content_type = self.environ.get('CONTENT_TYPE', '') + content_type = content_type.split(';', 1)[0].strip() + if content_type == 'application/json': + meth = self._lookup(method) + body = reader.read_chunk(sys.maxint) + return meth(args, body) + elif content_type == 'application/x-u1db-sync-stream': + meth_args = self._lookup('%s_args' % method) + meth_entry = self._lookup('%s_stream_entry' % method) + meth_end = self._lookup('%s_end' % method) + body_getline = reader.getline + if body_getline().strip() != '[': + raise BadRequest() + line = body_getline() + line, comma = utils.check_and_strip_comma(line.strip()) + meth_args(args, line) + while True: + line = body_getline() + entry = line.strip() + if entry == ']': + break + if not entry or not comma: # empty or no prec comma + raise BadRequest + entry, comma = utils.check_and_strip_comma(entry) + meth_entry({}, entry) + if comma or body_getline(): # extra comma or data + raise BadRequest + return meth_end() + else: + raise BadRequest() + + +class HTTPApp(object): + + # maximum allowed request body size + max_request_size = 15 * 1024 * 1024 # 15Mb + # maximum allowed entry/line size in request body + max_entry_size = 10 * 1024 * 1024 # 10Mb + + def __init__(self, state): + self.state = state + + def _lookup_resource(self, environ, responder): + resource_cls, params = url_to_resource.match(environ['PATH_INFO']) + if resource_cls is None: + raise BadRequest # 404 instead? + resource = resource_cls( + state=self.state, responder=responder, **params) + return resource + + def __call__(self, environ, start_response): + responder = HTTPResponder(start_response) + self.request_begin(environ) + try: + resource = self._lookup_resource(environ, responder) + HTTPInvocationByMethodWithBody(resource, environ, self)() + except errors.U1DBError as e: + self.request_u1db_error(environ, e) + status = http_errors.wire_description_to_status.get( + e.wire_description, 500) + responder.send_response_json(status, error=e.wire_description) + except BadRequest: + self.request_bad_request(environ) + responder.send_response_json(400, error="bad request") + except KeyboardInterrupt: + raise + except: + self.request_failed(environ) + raise + else: + self.request_done(environ) + return responder.content + + # hooks for tracing requests + + def request_begin(self, environ): + """Hook called at the beginning of processing a request.""" + pass + + def request_done(self, environ): + """Hook called when done processing a request.""" + pass + + def request_u1db_error(self, environ, exc): + """Hook called when processing a request resulted in a U1DBError. + + U1DBError passed as exc. + """ + pass + + def request_bad_request(self, environ): + """Hook called when processing a bad request. + + No actual processing was done. + """ + pass + + def request_failed(self, environ): + """Hook called when processing a request failed unexpectedly. + + Invoked from an except block, so there's interpreter exception + information available. + """ + pass |