560 lines
19 KiB
Python
560 lines
19 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2014-2016 OpenMarket Ltd
|
|
# Copyright 2018 New Vector Ltd
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
|
|
import collections
|
|
import html
|
|
import http.client
|
|
import logging
|
|
import types
|
|
import urllib
|
|
from io import BytesIO
|
|
|
|
from canonicaljson import encode_canonical_json, encode_pretty_printed_json, json
|
|
|
|
from twisted.internet import defer
|
|
from twisted.python import failure
|
|
from twisted.web import resource
|
|
from twisted.web.server import NOT_DONE_YET
|
|
from twisted.web.static import NoRangeStaticProducer
|
|
from twisted.web.util import redirectTo
|
|
|
|
import synapse.events
|
|
import synapse.metrics
|
|
from synapse.api.errors import (
|
|
CodeMessageException,
|
|
Codes,
|
|
RedirectException,
|
|
SynapseError,
|
|
UnrecognizedRequestError,
|
|
)
|
|
from synapse.logging.context import preserve_fn
|
|
from synapse.logging.opentracing import trace_servlet
|
|
from synapse.util.caches import intern_dict
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
HTML_ERROR_TEMPLATE = """<!DOCTYPE html>
|
|
<html lang=en>
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<title>Error {code}</title>
|
|
</head>
|
|
<body>
|
|
<p>{msg}</p>
|
|
</body>
|
|
</html>
|
|
"""
|
|
|
|
|
|
def wrap_json_request_handler(h):
|
|
"""Wraps a request handler method with exception handling.
|
|
|
|
Also does the wrapping with request.processing as per wrap_async_request_handler.
|
|
|
|
The handler method must have a signature of "handle_foo(self, request)",
|
|
where "request" must be a SynapseRequest.
|
|
|
|
The handler must return a deferred or a coroutine. If the deferred succeeds
|
|
we assume that a response has been sent. If the deferred fails with a SynapseError we use
|
|
it to send a JSON response with the appropriate HTTP reponse code. If the
|
|
deferred fails with any other type of error we send a 500 reponse.
|
|
"""
|
|
|
|
async def wrapped_request_handler(self, request):
|
|
try:
|
|
await h(self, request)
|
|
except SynapseError as e:
|
|
code = e.code
|
|
logger.info("%s SynapseError: %s - %s", request, code, e.msg)
|
|
|
|
# Only respond with an error response if we haven't already started
|
|
# writing, otherwise lets just kill the connection
|
|
if request.startedWriting:
|
|
if request.transport:
|
|
try:
|
|
request.transport.abortConnection()
|
|
except Exception:
|
|
# abortConnection throws if the connection is already closed
|
|
pass
|
|
else:
|
|
respond_with_json(
|
|
request,
|
|
code,
|
|
e.error_dict(),
|
|
send_cors=True,
|
|
pretty_print=_request_user_agent_is_curl(request),
|
|
)
|
|
|
|
except Exception:
|
|
# failure.Failure() fishes the original Failure out
|
|
# of our stack, and thus gives us a sensible stack
|
|
# trace.
|
|
f = failure.Failure()
|
|
logger.error(
|
|
"Failed handle request via %r: %r",
|
|
request.request_metrics.name,
|
|
request,
|
|
exc_info=(f.type, f.value, f.getTracebackObject()),
|
|
)
|
|
# Only respond with an error response if we haven't already started
|
|
# writing, otherwise lets just kill the connection
|
|
if request.startedWriting:
|
|
if request.transport:
|
|
try:
|
|
request.transport.abortConnection()
|
|
except Exception:
|
|
# abortConnection throws if the connection is already closed
|
|
pass
|
|
else:
|
|
respond_with_json(
|
|
request,
|
|
500,
|
|
{"error": "Internal server error", "errcode": Codes.UNKNOWN},
|
|
send_cors=True,
|
|
pretty_print=_request_user_agent_is_curl(request),
|
|
)
|
|
|
|
return wrap_async_request_handler(wrapped_request_handler)
|
|
|
|
|
|
def wrap_html_request_handler(h):
|
|
"""Wraps a request handler method with exception handling.
|
|
|
|
Also does the wrapping with request.processing as per wrap_async_request_handler.
|
|
|
|
The handler method must have a signature of "handle_foo(self, request)",
|
|
where "request" must be a SynapseRequest.
|
|
"""
|
|
|
|
async def wrapped_request_handler(self, request):
|
|
try:
|
|
return await h(self, request)
|
|
except Exception:
|
|
f = failure.Failure()
|
|
return _return_html_error(f, request)
|
|
|
|
return wrap_async_request_handler(wrapped_request_handler)
|
|
|
|
|
|
def _return_html_error(f, request):
|
|
"""Sends an HTML error page corresponding to the given failure
|
|
|
|
Args:
|
|
f (twisted.python.failure.Failure):
|
|
request (twisted.web.server.Request):
|
|
"""
|
|
if f.check(CodeMessageException):
|
|
cme = f.value
|
|
code = cme.code
|
|
msg = cme.msg
|
|
|
|
if isinstance(cme, RedirectException):
|
|
logger.info("%s redirect to %s", request, cme.location)
|
|
request.setHeader(b"location", cme.location)
|
|
request.cookies.extend(cme.cookies)
|
|
elif isinstance(cme, SynapseError):
|
|
logger.info("%s SynapseError: %s - %s", request, code, msg)
|
|
else:
|
|
logger.error(
|
|
"Failed handle request %r",
|
|
request,
|
|
exc_info=(f.type, f.value, f.getTracebackObject()),
|
|
)
|
|
else:
|
|
code = http.client.INTERNAL_SERVER_ERROR
|
|
msg = "Internal server error"
|
|
|
|
logger.error(
|
|
"Failed handle request %r",
|
|
request,
|
|
exc_info=(f.type, f.value, f.getTracebackObject()),
|
|
)
|
|
|
|
body = HTML_ERROR_TEMPLATE.format(code=code, msg=html.escape(msg)).encode("utf-8")
|
|
request.setResponseCode(code)
|
|
request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
|
|
request.setHeader(b"Content-Length", b"%i" % (len(body),))
|
|
request.write(body)
|
|
finish_request(request)
|
|
|
|
|
|
def wrap_async_request_handler(h):
|
|
"""Wraps an async request handler so that it calls request.processing.
|
|
|
|
This helps ensure that work done by the request handler after the request is completed
|
|
is correctly recorded against the request metrics/logs.
|
|
|
|
The handler method must have a signature of "handle_foo(self, request)",
|
|
where "request" must be a SynapseRequest.
|
|
|
|
The handler may return a deferred, in which case the completion of the request isn't
|
|
logged until the deferred completes.
|
|
"""
|
|
|
|
async def wrapped_async_request_handler(self, request):
|
|
with request.processing():
|
|
await h(self, request)
|
|
|
|
# we need to preserve_fn here, because the synchronous render method won't yield for
|
|
# us (obviously)
|
|
return preserve_fn(wrapped_async_request_handler)
|
|
|
|
|
|
class HttpServer(object):
|
|
""" Interface for registering callbacks on a HTTP server
|
|
"""
|
|
|
|
def register_paths(self, method, path_patterns, callback):
|
|
""" Register a callback that gets fired if we receive a http request
|
|
with the given method for a path that matches the given regex.
|
|
|
|
If the regex contains groups these gets passed to the calback via
|
|
an unpacked tuple.
|
|
|
|
Args:
|
|
method (str): The method to listen to.
|
|
path_patterns (list<SRE_Pattern>): The regex used to match requests.
|
|
callback (function): The function to fire if we receive a matched
|
|
request. The first argument will be the request object and
|
|
subsequent arguments will be any matched groups from the regex.
|
|
This should return a tuple of (code, response).
|
|
"""
|
|
pass
|
|
|
|
|
|
class JsonResource(HttpServer, resource.Resource):
|
|
""" This implements the HttpServer interface and provides JSON support for
|
|
Resources.
|
|
|
|
Register callbacks via register_paths()
|
|
|
|
Callbacks can return a tuple of status code and a dict in which case the
|
|
the dict will automatically be sent to the client as a JSON object.
|
|
|
|
The JsonResource is primarily intended for returning JSON, but callbacks
|
|
may send something other than JSON, they may do so by using the methods
|
|
on the request object and instead returning None.
|
|
"""
|
|
|
|
isLeaf = True
|
|
|
|
_PathEntry = collections.namedtuple(
|
|
"_PathEntry", ["pattern", "callback", "servlet_classname"]
|
|
)
|
|
|
|
def __init__(self, hs, canonical_json=True):
|
|
resource.Resource.__init__(self)
|
|
|
|
self.canonical_json = canonical_json
|
|
self.clock = hs.get_clock()
|
|
self.path_regexs = {}
|
|
self.hs = hs
|
|
|
|
def register_paths(
|
|
self, method, path_patterns, callback, servlet_classname, trace=True
|
|
):
|
|
"""
|
|
Registers a request handler against a regular expression. Later request URLs are
|
|
checked against these regular expressions in order to identify an appropriate
|
|
handler for that request.
|
|
|
|
Args:
|
|
method (str): GET, POST etc
|
|
|
|
path_patterns (Iterable[str]): A list of regular expressions to which
|
|
the request URLs are compared.
|
|
|
|
callback (function): The handler for the request. Usually a Servlet
|
|
|
|
servlet_classname (str): The name of the handler to be used in prometheus
|
|
and opentracing logs.
|
|
|
|
trace (bool): Whether we should start a span to trace the servlet.
|
|
"""
|
|
method = method.encode("utf-8") # method is bytes on py3
|
|
|
|
if trace:
|
|
# We don't extract the context from the servlet because we can't
|
|
# trust the sender
|
|
callback = trace_servlet(servlet_classname)(callback)
|
|
|
|
for path_pattern in path_patterns:
|
|
logger.debug("Registering for %s %s", method, path_pattern.pattern)
|
|
self.path_regexs.setdefault(method, []).append(
|
|
self._PathEntry(path_pattern, callback, servlet_classname)
|
|
)
|
|
|
|
def render(self, request):
|
|
""" This gets called by twisted every time someone sends us a request.
|
|
"""
|
|
defer.ensureDeferred(self._async_render(request))
|
|
return NOT_DONE_YET
|
|
|
|
@wrap_json_request_handler
|
|
async def _async_render(self, request):
|
|
""" This gets called from render() every time someone sends us a request.
|
|
This checks if anyone has registered a callback for that method and
|
|
path.
|
|
"""
|
|
callback, servlet_classname, group_dict = self._get_handler_for_request(request)
|
|
|
|
# Make sure we have a name for this handler in prometheus.
|
|
request.request_metrics.name = servlet_classname
|
|
|
|
# Now trigger the callback. If it returns a response, we send it
|
|
# here. If it throws an exception, that is handled by the wrapper
|
|
# installed by @request_handler.
|
|
kwargs = intern_dict(
|
|
{
|
|
name: urllib.parse.unquote(value) if value else value
|
|
for name, value in group_dict.items()
|
|
}
|
|
)
|
|
|
|
callback_return = callback(request, **kwargs)
|
|
|
|
# Is it synchronous? We'll allow this for now.
|
|
if isinstance(callback_return, (defer.Deferred, types.CoroutineType)):
|
|
callback_return = await callback_return
|
|
|
|
if callback_return is not None:
|
|
code, response = callback_return
|
|
self._send_response(request, code, response)
|
|
|
|
def _get_handler_for_request(self, request):
|
|
"""Finds a callback method to handle the given request
|
|
|
|
Args:
|
|
request (twisted.web.http.Request):
|
|
|
|
Returns:
|
|
Tuple[Callable, str, dict[unicode, unicode]]: callback method, the
|
|
label to use for that method in prometheus metrics, and the
|
|
dict mapping keys to path components as specified in the
|
|
handler's path match regexp.
|
|
|
|
The callback will normally be a method registered via
|
|
register_paths, so will return (possibly via Deferred) either
|
|
None, or a tuple of (http code, response body).
|
|
"""
|
|
if request.method == b"OPTIONS":
|
|
return _options_handler, "options_request_handler", {}
|
|
|
|
request_path = request.path.decode("ascii")
|
|
|
|
# Loop through all the registered callbacks to check if the method
|
|
# and path regex match
|
|
for path_entry in self.path_regexs.get(request.method, []):
|
|
m = path_entry.pattern.match(request_path)
|
|
if m:
|
|
# We found a match!
|
|
return path_entry.callback, path_entry.servlet_classname, m.groupdict()
|
|
|
|
# Huh. No one wanted to handle that? Fiiiiiine. Send 400.
|
|
return _unrecognised_request_handler, "unrecognised_request_handler", {}
|
|
|
|
def _send_response(
|
|
self, request, code, response_json_object, response_code_message=None
|
|
):
|
|
# TODO: Only enable CORS for the requests that need it.
|
|
respond_with_json(
|
|
request,
|
|
code,
|
|
response_json_object,
|
|
send_cors=True,
|
|
response_code_message=response_code_message,
|
|
pretty_print=_request_user_agent_is_curl(request),
|
|
canonical_json=self.canonical_json,
|
|
)
|
|
|
|
|
|
class DirectServeResource(resource.Resource):
|
|
def render(self, request):
|
|
"""
|
|
Render the request, using an asynchronous render handler if it exists.
|
|
"""
|
|
async_render_callback_name = "_async_render_" + request.method.decode("ascii")
|
|
|
|
# Try and get the async renderer
|
|
callback = getattr(self, async_render_callback_name, None)
|
|
|
|
# No async renderer for this request method.
|
|
if not callback:
|
|
return super().render(request)
|
|
|
|
resp = trace_servlet(self.__class__.__name__)(callback)(request)
|
|
|
|
# If it's a coroutine, turn it into a Deferred
|
|
if isinstance(resp, types.CoroutineType):
|
|
defer.ensureDeferred(resp)
|
|
|
|
return NOT_DONE_YET
|
|
|
|
|
|
def _options_handler(request):
|
|
"""Request handler for OPTIONS requests
|
|
|
|
This is a request handler suitable for return from
|
|
_get_handler_for_request. It returns a 200 and an empty body.
|
|
|
|
Args:
|
|
request (twisted.web.http.Request):
|
|
|
|
Returns:
|
|
Tuple[int, dict]: http code, response body.
|
|
"""
|
|
return 200, {}
|
|
|
|
|
|
def _unrecognised_request_handler(request):
|
|
"""Request handler for unrecognised requests
|
|
|
|
This is a request handler suitable for return from
|
|
_get_handler_for_request. It actually just raises an
|
|
UnrecognizedRequestError.
|
|
|
|
Args:
|
|
request (twisted.web.http.Request):
|
|
"""
|
|
raise UnrecognizedRequestError()
|
|
|
|
|
|
class RootRedirect(resource.Resource):
|
|
"""Redirects the root '/' path to another path."""
|
|
|
|
def __init__(self, path):
|
|
resource.Resource.__init__(self)
|
|
self.url = path
|
|
|
|
def render_GET(self, request):
|
|
return redirectTo(self.url.encode("ascii"), request)
|
|
|
|
def getChild(self, name, request):
|
|
if len(name) == 0:
|
|
return self # select ourselves as the child to render
|
|
return resource.Resource.getChild(self, name, request)
|
|
|
|
|
|
def respond_with_json(
|
|
request,
|
|
code,
|
|
json_object,
|
|
send_cors=False,
|
|
response_code_message=None,
|
|
pretty_print=False,
|
|
canonical_json=True,
|
|
):
|
|
# could alternatively use request.notifyFinish() and flip a flag when
|
|
# the Deferred fires, but since the flag is RIGHT THERE it seems like
|
|
# a waste.
|
|
if request._disconnected:
|
|
logger.warning(
|
|
"Not sending response to request %s, already disconnected.", request
|
|
)
|
|
return
|
|
|
|
if pretty_print:
|
|
json_bytes = encode_pretty_printed_json(json_object) + b"\n"
|
|
else:
|
|
if canonical_json or synapse.events.USE_FROZEN_DICTS:
|
|
# canonicaljson already encodes to bytes
|
|
json_bytes = encode_canonical_json(json_object)
|
|
else:
|
|
json_bytes = json.dumps(json_object).encode("utf-8")
|
|
|
|
return respond_with_json_bytes(
|
|
request,
|
|
code,
|
|
json_bytes,
|
|
send_cors=send_cors,
|
|
response_code_message=response_code_message,
|
|
)
|
|
|
|
|
|
def respond_with_json_bytes(
|
|
request, code, json_bytes, send_cors=False, response_code_message=None
|
|
):
|
|
"""Sends encoded JSON in response to the given request.
|
|
|
|
Args:
|
|
request (twisted.web.http.Request): The http request to respond to.
|
|
code (int): The HTTP response code.
|
|
json_bytes (bytes): The json bytes to use as the response body.
|
|
send_cors (bool): Whether to send Cross-Origin Resource Sharing headers
|
|
http://www.w3.org/TR/cors/
|
|
Returns:
|
|
twisted.web.server.NOT_DONE_YET"""
|
|
|
|
request.setResponseCode(code, message=response_code_message)
|
|
request.setHeader(b"Content-Type", b"application/json")
|
|
request.setHeader(b"Content-Length", b"%d" % (len(json_bytes),))
|
|
request.setHeader(b"Cache-Control", b"no-cache, no-store, must-revalidate")
|
|
|
|
if send_cors:
|
|
set_cors_headers(request)
|
|
|
|
# todo: we can almost certainly avoid this copy and encode the json straight into
|
|
# the bytesIO, but it would involve faffing around with string->bytes wrappers.
|
|
bytes_io = BytesIO(json_bytes)
|
|
|
|
producer = NoRangeStaticProducer(request, bytes_io)
|
|
producer.start()
|
|
return NOT_DONE_YET
|
|
|
|
|
|
def set_cors_headers(request):
|
|
"""Set the CORs headers so that javascript running in a web browsers can
|
|
use this API
|
|
|
|
Args:
|
|
request (twisted.web.http.Request): The http request to add CORs to.
|
|
"""
|
|
request.setHeader(b"Access-Control-Allow-Origin", b"*")
|
|
request.setHeader(
|
|
b"Access-Control-Allow-Methods", b"GET, POST, PUT, DELETE, OPTIONS"
|
|
)
|
|
request.setHeader(
|
|
b"Access-Control-Allow-Headers",
|
|
b"Origin, X-Requested-With, Content-Type, Accept, Authorization",
|
|
)
|
|
|
|
|
|
def finish_request(request):
|
|
""" Finish writing the response to the request.
|
|
|
|
Twisted throws a RuntimeException if the connection closed before the
|
|
response was written but doesn't provide a convenient or reliable way to
|
|
determine if the connection was closed. So we catch and log the RuntimeException
|
|
|
|
You might think that ``request.notifyFinish`` could be used to tell if the
|
|
request was finished. However the deferred it returns won't fire if the
|
|
connection was already closed, meaning we'd have to have called the method
|
|
right at the start of the request. By the time we want to write the response
|
|
it will already be too late.
|
|
"""
|
|
try:
|
|
request.finish()
|
|
except RuntimeError as e:
|
|
logger.info("Connection disconnected before response was written: %r", e)
|
|
|
|
|
|
def _request_user_agent_is_curl(request):
|
|
user_agents = request.requestHeaders.getRawHeaders(b"User-Agent", default=[])
|
|
for user_agent in user_agents:
|
|
if b"curl" in user_agent:
|
|
return True
|
|
return False
|