forked-synapse/synapse/http/matrixfederationclient.py
Patrick Cloke 58114f8a17
Create a SynapseReactor type which incorporates the necessary reactor interfaces. (#9528)
This helps fix some type hints when running with Twisted 21.2.0.
2021-03-08 08:25:43 -05:00

1069 lines
37 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 cgi
import logging
import random
import sys
import urllib.parse
from io import BytesIO
from typing import Callable, Dict, List, Optional, Tuple, Union
import attr
import treq
from canonicaljson import encode_canonical_json
from prometheus_client import Counter
from signedjson.sign import sign_json
from twisted.internet import defer
from twisted.internet.error import DNSLookupError
from twisted.internet.interfaces import IReactorTime
from twisted.internet.task import _EPSILON, Cooperator
from twisted.web.http_headers import Headers
from twisted.web.iweb import IBodyProducer, IResponse
import synapse.metrics
import synapse.util.retryutils
from synapse.api.errors import (
Codes,
FederationDeniedError,
HttpResponseException,
RequestSendFailed,
SynapseError,
)
from synapse.http import QuieterFileBodyProducer
from synapse.http.client import (
BlacklistingAgentWrapper,
BlacklistingReactorWrapper,
BodyExceededMaxSize,
encode_query_args,
read_body_with_max_size,
)
from synapse.http.federation.matrix_federation_agent import MatrixFederationAgent
from synapse.logging.context import make_deferred_yieldable
from synapse.logging.opentracing import (
inject_active_span_byte_dict,
set_tag,
start_active_span,
tags,
)
from synapse.types import ISynapseReactor, JsonDict
from synapse.util import json_decoder
from synapse.util.async_helpers import timeout_deferred
from synapse.util.metrics import Measure
logger = logging.getLogger(__name__)
outgoing_requests_counter = Counter(
"synapse_http_matrixfederationclient_requests", "", ["method"]
)
incoming_responses_counter = Counter(
"synapse_http_matrixfederationclient_responses", "", ["method", "code"]
)
MAX_LONG_RETRIES = 10
MAX_SHORT_RETRIES = 3
MAXINT = sys.maxsize
_next_id = 1
QueryArgs = Dict[str, Union[str, List[str]]]
@attr.s(slots=True, frozen=True)
class MatrixFederationRequest:
method = attr.ib(type=str)
"""HTTP method
"""
path = attr.ib(type=str)
"""HTTP path
"""
destination = attr.ib(type=str)
"""The remote server to send the HTTP request to.
"""
json = attr.ib(default=None, type=Optional[JsonDict])
"""JSON to send in the body.
"""
json_callback = attr.ib(default=None, type=Optional[Callable[[], JsonDict]])
"""A callback to generate the JSON.
"""
query = attr.ib(default=None, type=Optional[dict])
"""Query arguments.
"""
txn_id = attr.ib(default=None, type=Optional[str])
"""Unique ID for this request (for logging)
"""
uri = attr.ib(init=False, type=bytes)
"""The URI of this request
"""
def __attrs_post_init__(self) -> None:
global _next_id
txn_id = "%s-O-%s" % (self.method, _next_id)
_next_id = (_next_id + 1) % (MAXINT - 1)
object.__setattr__(self, "txn_id", txn_id)
destination_bytes = self.destination.encode("ascii")
path_bytes = self.path.encode("ascii")
if self.query:
query_bytes = encode_query_args(self.query)
else:
query_bytes = b""
# The object is frozen so we can pre-compute this.
uri = urllib.parse.urlunparse(
(b"matrix", destination_bytes, path_bytes, None, query_bytes, b"")
)
object.__setattr__(self, "uri", uri)
def get_json(self) -> Optional[JsonDict]:
if self.json_callback:
return self.json_callback()
return self.json
async def _handle_json_response(
reactor: IReactorTime,
timeout_sec: float,
request: MatrixFederationRequest,
response: IResponse,
start_ms: int,
) -> JsonDict:
"""
Reads the JSON body of a response, with a timeout
Args:
reactor: twisted reactor, for the timeout
timeout_sec: number of seconds to wait for response to complete
request: the request that triggered the response
response: response to the request
start_ms: Timestamp when request was made
Returns:
The parsed JSON response
"""
try:
check_content_type_is_json(response.headers)
# Use the custom JSON decoder (partially re-implements treq.json_content).
d = treq.text_content(response, encoding="utf-8")
d.addCallback(json_decoder.decode)
d = timeout_deferred(d, timeout=timeout_sec, reactor=reactor)
body = await make_deferred_yieldable(d)
except ValueError as e:
# The JSON content was invalid.
logger.warning(
"{%s} [%s] Failed to parse JSON response - %s %s",
request.txn_id,
request.destination,
request.method,
request.uri.decode("ascii"),
)
raise RequestSendFailed(e, can_retry=False) from e
except defer.TimeoutError as e:
logger.warning(
"{%s} [%s] Timed out reading response - %s %s",
request.txn_id,
request.destination,
request.method,
request.uri.decode("ascii"),
)
raise RequestSendFailed(e, can_retry=True) from e
except Exception as e:
logger.warning(
"{%s} [%s] Error reading response %s %s: %s",
request.txn_id,
request.destination,
request.method,
request.uri.decode("ascii"),
e,
)
raise
time_taken_secs = reactor.seconds() - start_ms / 1000
logger.info(
"{%s} [%s] Completed request: %d %s in %.2f secs - %s %s",
request.txn_id,
request.destination,
response.code,
response.phrase.decode("ascii", errors="replace"),
time_taken_secs,
request.method,
request.uri.decode("ascii"),
)
return body
class MatrixFederationHttpClient:
"""HTTP client used to talk to other homeservers over the federation
protocol. Send client certificates and signs requests.
Attributes:
agent (twisted.web.client.Agent): The twisted Agent used to send the
requests.
"""
def __init__(self, hs, tls_client_options_factory):
self.hs = hs
self.signing_key = hs.signing_key
self.server_name = hs.hostname
# We need to use a DNS resolver which filters out blacklisted IP
# addresses, to prevent DNS rebinding.
self.reactor = BlacklistingReactorWrapper(
hs.get_reactor(), None, hs.config.federation_ip_range_blacklist
) # type: ISynapseReactor
user_agent = hs.version_string
if hs.config.user_agent_suffix:
user_agent = "%s %s" % (user_agent, hs.config.user_agent_suffix)
user_agent = user_agent.encode("ascii")
federation_agent = MatrixFederationAgent(
self.reactor,
tls_client_options_factory,
user_agent,
hs.config.federation_ip_range_blacklist,
)
# Use a BlacklistingAgentWrapper to prevent circumventing the IP
# blacklist via IP literals in server names
self.agent = BlacklistingAgentWrapper(
federation_agent,
ip_blacklist=hs.config.federation_ip_range_blacklist,
)
self.clock = hs.get_clock()
self._store = hs.get_datastore()
self.version_string_bytes = hs.version_string.encode("ascii")
self.default_timeout = 60
def schedule(x):
self.reactor.callLater(_EPSILON, x)
self._cooperator = Cooperator(scheduler=schedule)
async def _send_request_with_optional_trailing_slash(
self,
request: MatrixFederationRequest,
try_trailing_slash_on_400: bool = False,
**send_request_args
) -> IResponse:
"""Wrapper for _send_request which can optionally retry the request
upon receiving a combination of a 400 HTTP response code and a
'M_UNRECOGNIZED' errcode. This is a workaround for Synapse <= v0.99.3
due to #3622.
Args:
request: details of request to be sent
try_trailing_slash_on_400: Whether on receiving a 400
'M_UNRECOGNIZED' from the server to retry the request with a
trailing slash appended to the request path.
send_request_args: A dictionary of arguments to pass to `_send_request()`.
Raises:
HttpResponseException: If we get an HTTP response code >= 300
(except 429).
Returns:
Parsed JSON response body.
"""
try:
response = await self._send_request(request, **send_request_args)
except HttpResponseException as e:
# Received an HTTP error > 300. Check if it meets the requirements
# to retry with a trailing slash
if not try_trailing_slash_on_400:
raise
if e.code != 400 or e.to_synapse_error().errcode != "M_UNRECOGNIZED":
raise
# Retry with a trailing slash if we received a 400 with
# 'M_UNRECOGNIZED' which some endpoints can return when omitting a
# trailing slash on Synapse <= v0.99.3.
logger.info("Retrying request with trailing slash")
# Request is frozen so we create a new instance
request = attr.evolve(request, path=request.path + "/")
response = await self._send_request(request, **send_request_args)
return response
async def _send_request(
self,
request: MatrixFederationRequest,
retry_on_dns_fail: bool = True,
timeout: Optional[int] = None,
long_retries: bool = False,
ignore_backoff: bool = False,
backoff_on_404: bool = False,
) -> IResponse:
"""
Sends a request to the given server.
Args:
request: details of request to be sent
retry_on_dns_fail: true if the request should be retied on DNS failures
timeout: number of milliseconds to wait for the response headers
(including connecting to the server), *for each attempt*.
60s by default.
long_retries: whether to use the long retry algorithm.
The regular retry algorithm makes 4 attempts, with intervals
[0.5s, 1s, 2s].
The long retry algorithm makes 11 attempts, with intervals
[4s, 16s, 60s, 60s, ...]
Both algorithms add -20%/+40% jitter to the retry intervals.
Note that the above intervals are *in addition* to the time spent
waiting for the request to complete (up to `timeout` ms).
NB: the long retry algorithm takes over 20 minutes to complete, with
a default timeout of 60s!
ignore_backoff: true to ignore the historical backoff data
and try the request anyway.
backoff_on_404: Back off if we get a 404
Returns:
Resolves with the HTTP response object on success.
Raises:
HttpResponseException: If we get an HTTP response code >= 300
(except 429).
NotRetryingDestination: If we are not yet ready to retry this
server.
FederationDeniedError: If this destination is not on our
federation whitelist
RequestSendFailed: If there were problems connecting to the
remote, due to e.g. DNS failures, connection timeouts etc.
"""
if timeout:
_sec_timeout = timeout / 1000
else:
_sec_timeout = self.default_timeout
if (
self.hs.config.federation_domain_whitelist is not None
and request.destination not in self.hs.config.federation_domain_whitelist
):
raise FederationDeniedError(request.destination)
limiter = await synapse.util.retryutils.get_retry_limiter(
request.destination,
self.clock,
self._store,
backoff_on_404=backoff_on_404,
ignore_backoff=ignore_backoff,
)
method_bytes = request.method.encode("ascii")
destination_bytes = request.destination.encode("ascii")
path_bytes = request.path.encode("ascii")
if request.query:
query_bytes = encode_query_args(request.query)
else:
query_bytes = b""
scope = start_active_span(
"outgoing-federation-request",
tags={
tags.SPAN_KIND: tags.SPAN_KIND_RPC_CLIENT,
tags.PEER_ADDRESS: request.destination,
tags.HTTP_METHOD: request.method,
tags.HTTP_URL: request.path,
},
finish_on_close=True,
)
# Inject the span into the headers
headers_dict = {} # type: Dict[bytes, List[bytes]]
inject_active_span_byte_dict(headers_dict, request.destination)
headers_dict[b"User-Agent"] = [self.version_string_bytes]
with limiter, scope:
# XXX: Would be much nicer to retry only at the transaction-layer
# (once we have reliable transactions in place)
if long_retries:
retries_left = MAX_LONG_RETRIES
else:
retries_left = MAX_SHORT_RETRIES
url_bytes = request.uri
url_str = url_bytes.decode("ascii")
url_to_sign_bytes = urllib.parse.urlunparse(
(b"", b"", path_bytes, None, query_bytes, b"")
)
while True:
try:
json = request.get_json()
if json:
headers_dict[b"Content-Type"] = [b"application/json"]
auth_headers = self.build_auth_headers(
destination_bytes, method_bytes, url_to_sign_bytes, json
)
data = encode_canonical_json(json)
producer = QuieterFileBodyProducer(
BytesIO(data), cooperator=self._cooperator
) # type: Optional[IBodyProducer]
else:
producer = None
auth_headers = self.build_auth_headers(
destination_bytes, method_bytes, url_to_sign_bytes
)
headers_dict[b"Authorization"] = auth_headers
logger.debug(
"{%s} [%s] Sending request: %s %s; timeout %fs",
request.txn_id,
request.destination,
request.method,
url_str,
_sec_timeout,
)
outgoing_requests_counter.labels(request.method).inc()
try:
with Measure(self.clock, "outbound_request"):
# we don't want all the fancy cookie and redirect handling
# that treq.request gives: just use the raw Agent.
request_deferred = self.agent.request(
method_bytes,
url_bytes,
headers=Headers(headers_dict),
bodyProducer=producer,
)
request_deferred = timeout_deferred(
request_deferred,
timeout=_sec_timeout,
reactor=self.reactor,
)
response = await request_deferred
except DNSLookupError as e:
raise RequestSendFailed(e, can_retry=retry_on_dns_fail) from e
except Exception as e:
raise RequestSendFailed(e, can_retry=True) from e
incoming_responses_counter.labels(
request.method, response.code
).inc()
set_tag(tags.HTTP_STATUS_CODE, response.code)
response_phrase = response.phrase.decode("ascii", errors="replace")
if 200 <= response.code < 300:
logger.debug(
"{%s} [%s] Got response headers: %d %s",
request.txn_id,
request.destination,
response.code,
response_phrase,
)
pass
else:
logger.info(
"{%s} [%s] Got response headers: %d %s",
request.txn_id,
request.destination,
response.code,
response_phrase,
)
# :'(
# Update transactions table?
d = treq.content(response)
d = timeout_deferred(
d, timeout=_sec_timeout, reactor=self.reactor
)
try:
body = await make_deferred_yieldable(d)
except Exception as e:
# Eh, we're already going to raise an exception so lets
# ignore if this fails.
logger.warning(
"{%s} [%s] Failed to get error response: %s %s: %s",
request.txn_id,
request.destination,
request.method,
url_str,
_flatten_response_never_received(e),
)
body = None
exc = HttpResponseException(
response.code, response_phrase, body
)
# Retry if the error is a 429 (Too Many Requests),
# otherwise just raise a standard HttpResponseException
if response.code == 429:
raise RequestSendFailed(exc, can_retry=True) from exc
else:
raise exc
break
except RequestSendFailed as e:
logger.info(
"{%s} [%s] Request failed: %s %s: %s",
request.txn_id,
request.destination,
request.method,
url_str,
_flatten_response_never_received(e.inner_exception),
)
if not e.can_retry:
raise
if retries_left and not timeout:
if long_retries:
delay = 4 ** (MAX_LONG_RETRIES + 1 - retries_left)
delay = min(delay, 60)
delay *= random.uniform(0.8, 1.4)
else:
delay = 0.5 * 2 ** (MAX_SHORT_RETRIES - retries_left)
delay = min(delay, 2)
delay *= random.uniform(0.8, 1.4)
logger.debug(
"{%s} [%s] Waiting %ss before re-sending...",
request.txn_id,
request.destination,
delay,
)
await self.clock.sleep(delay)
retries_left -= 1
else:
raise
except Exception as e:
logger.warning(
"{%s} [%s] Request failed: %s %s: %s",
request.txn_id,
request.destination,
request.method,
url_str,
_flatten_response_never_received(e),
)
raise
return response
def build_auth_headers(
self,
destination: Optional[bytes],
method: bytes,
url_bytes: bytes,
content: Optional[JsonDict] = None,
destination_is: Optional[bytes] = None,
) -> List[bytes]:
"""
Builds the Authorization headers for a federation request
Args:
destination: The destination homeserver of the request.
May be None if the destination is an identity server, in which case
destination_is must be non-None.
method: The HTTP method of the request
url_bytes: The URI path of the request
content: The body of the request
destination_is: As 'destination', but if the destination is an
identity server
Returns:
A list of headers to be added as "Authorization:" headers
"""
request = {
"method": method.decode("ascii"),
"uri": url_bytes.decode("ascii"),
"origin": self.server_name,
}
if destination is not None:
request["destination"] = destination.decode("ascii")
if destination_is is not None:
request["destination_is"] = destination_is.decode("ascii")
if content is not None:
request["content"] = content
request = sign_json(request, self.server_name, self.signing_key)
auth_headers = []
for key, sig in request["signatures"][self.server_name].items():
auth_headers.append(
(
'X-Matrix origin=%s,key="%s",sig="%s"'
% (self.server_name, key, sig)
).encode("ascii")
)
return auth_headers
async def put_json(
self,
destination: str,
path: str,
args: Optional[QueryArgs] = None,
data: Optional[JsonDict] = None,
json_data_callback: Optional[Callable[[], JsonDict]] = None,
long_retries: bool = False,
timeout: Optional[int] = None,
ignore_backoff: bool = False,
backoff_on_404: bool = False,
try_trailing_slash_on_400: bool = False,
) -> Union[JsonDict, list]:
"""Sends the specified json data using PUT
Args:
destination: The remote server to send the HTTP request to.
path: The HTTP path.
args: query params
data: A dict containing the data that will be used as
the request body. This will be encoded as JSON.
json_data_callback: A callable returning the dict to
use as the request body.
long_retries: whether to use the long retry algorithm. See
docs on _send_request for details.
timeout: number of milliseconds to wait for the response.
self._default_timeout (60s) by default.
Note that we may make several attempts to send the request; this
timeout applies to the time spent waiting for response headers for
*each* attempt (including connection time) as well as the time spent
reading the response body after a 200 response.
ignore_backoff: true to ignore the historical backoff data
and try the request anyway.
backoff_on_404: True if we should count a 404 response as
a failure of the server (and should therefore back off future
requests).
try_trailing_slash_on_400: True if on a 400 M_UNRECOGNIZED
response we should try appending a trailing slash to the end
of the request. Workaround for #3622 in Synapse <= v0.99.3. This
will be attempted before backing off if backing off has been
enabled.
Returns:
Succeeds when we get a 2xx HTTP response. The
result will be the decoded JSON body.
Raises:
HttpResponseException: If we get an HTTP response code >= 300
(except 429).
NotRetryingDestination: If we are not yet ready to retry this
server.
FederationDeniedError: If this destination is not on our
federation whitelist
RequestSendFailed: If there were problems connecting to the
remote, due to e.g. DNS failures, connection timeouts etc.
"""
request = MatrixFederationRequest(
method="PUT",
destination=destination,
path=path,
query=args,
json_callback=json_data_callback,
json=data,
)
start_ms = self.clock.time_msec()
response = await self._send_request_with_optional_trailing_slash(
request,
try_trailing_slash_on_400,
backoff_on_404=backoff_on_404,
ignore_backoff=ignore_backoff,
long_retries=long_retries,
timeout=timeout,
)
if timeout is not None:
_sec_timeout = timeout / 1000
else:
_sec_timeout = self.default_timeout
body = await _handle_json_response(
self.reactor, _sec_timeout, request, response, start_ms
)
return body
async def post_json(
self,
destination: str,
path: str,
data: Optional[JsonDict] = None,
long_retries: bool = False,
timeout: Optional[int] = None,
ignore_backoff: bool = False,
args: Optional[QueryArgs] = None,
) -> Union[JsonDict, list]:
"""Sends the specified json data using POST
Args:
destination: The remote server to send the HTTP request to.
path: The HTTP path.
data: A dict containing the data that will be used as
the request body. This will be encoded as JSON.
long_retries: whether to use the long retry algorithm. See
docs on _send_request for details.
timeout: number of milliseconds to wait for the response.
self._default_timeout (60s) by default.
Note that we may make several attempts to send the request; this
timeout applies to the time spent waiting for response headers for
*each* attempt (including connection time) as well as the time spent
reading the response body after a 200 response.
ignore_backoff: true to ignore the historical backoff data and
try the request anyway.
args: query params
Returns:
dict|list: Succeeds when we get a 2xx HTTP response. The
result will be the decoded JSON body.
Raises:
HttpResponseException: If we get an HTTP response code >= 300
(except 429).
NotRetryingDestination: If we are not yet ready to retry this
server.
FederationDeniedError: If this destination is not on our
federation whitelist
RequestSendFailed: If there were problems connecting to the
remote, due to e.g. DNS failures, connection timeouts etc.
"""
request = MatrixFederationRequest(
method="POST", destination=destination, path=path, query=args, json=data
)
start_ms = self.clock.time_msec()
response = await self._send_request(
request,
long_retries=long_retries,
timeout=timeout,
ignore_backoff=ignore_backoff,
)
if timeout:
_sec_timeout = timeout / 1000
else:
_sec_timeout = self.default_timeout
body = await _handle_json_response(
self.reactor,
_sec_timeout,
request,
response,
start_ms,
)
return body
async def get_json(
self,
destination: str,
path: str,
args: Optional[QueryArgs] = None,
retry_on_dns_fail: bool = True,
timeout: Optional[int] = None,
ignore_backoff: bool = False,
try_trailing_slash_on_400: bool = False,
) -> Union[JsonDict, list]:
"""GETs some json from the given host homeserver and path
Args:
destination: The remote server to send the HTTP request to.
path: The HTTP path.
args: A dictionary used to create query strings, defaults to
None.
timeout: number of milliseconds to wait for the response.
self._default_timeout (60s) by default.
Note that we may make several attempts to send the request; this
timeout applies to the time spent waiting for response headers for
*each* attempt (including connection time) as well as the time spent
reading the response body after a 200 response.
ignore_backoff: true to ignore the historical backoff data
and try the request anyway.
try_trailing_slash_on_400: True if on a 400 M_UNRECOGNIZED
response we should try appending a trailing slash to the end of
the request. Workaround for #3622 in Synapse <= v0.99.3.
Returns:
Succeeds when we get a 2xx HTTP response. The
result will be the decoded JSON body.
Raises:
HttpResponseException: If we get an HTTP response code >= 300
(except 429).
NotRetryingDestination: If we are not yet ready to retry this
server.
FederationDeniedError: If this destination is not on our
federation whitelist
RequestSendFailed: If there were problems connecting to the
remote, due to e.g. DNS failures, connection timeouts etc.
"""
request = MatrixFederationRequest(
method="GET", destination=destination, path=path, query=args
)
start_ms = self.clock.time_msec()
response = await self._send_request_with_optional_trailing_slash(
request,
try_trailing_slash_on_400,
backoff_on_404=False,
ignore_backoff=ignore_backoff,
retry_on_dns_fail=retry_on_dns_fail,
timeout=timeout,
)
if timeout is not None:
_sec_timeout = timeout / 1000
else:
_sec_timeout = self.default_timeout
body = await _handle_json_response(
self.reactor, _sec_timeout, request, response, start_ms
)
return body
async def delete_json(
self,
destination: str,
path: str,
long_retries: bool = False,
timeout: Optional[int] = None,
ignore_backoff: bool = False,
args: Optional[QueryArgs] = None,
) -> Union[JsonDict, list]:
"""Send a DELETE request to the remote expecting some json response
Args:
destination: The remote server to send the HTTP request to.
path: The HTTP path.
long_retries: whether to use the long retry algorithm. See
docs on _send_request for details.
timeout: number of milliseconds to wait for the response.
self._default_timeout (60s) by default.
Note that we may make several attempts to send the request; this
timeout applies to the time spent waiting for response headers for
*each* attempt (including connection time) as well as the time spent
reading the response body after a 200 response.
ignore_backoff: true to ignore the historical backoff data and
try the request anyway.
args: query params
Returns:
Succeeds when we get a 2xx HTTP response. The
result will be the decoded JSON body.
Raises:
HttpResponseException: If we get an HTTP response code >= 300
(except 429).
NotRetryingDestination: If we are not yet ready to retry this
server.
FederationDeniedError: If this destination is not on our
federation whitelist
RequestSendFailed: If there were problems connecting to the
remote, due to e.g. DNS failures, connection timeouts etc.
"""
request = MatrixFederationRequest(
method="DELETE", destination=destination, path=path, query=args
)
start_ms = self.clock.time_msec()
response = await self._send_request(
request,
long_retries=long_retries,
timeout=timeout,
ignore_backoff=ignore_backoff,
)
if timeout is not None:
_sec_timeout = timeout / 1000
else:
_sec_timeout = self.default_timeout
body = await _handle_json_response(
self.reactor, _sec_timeout, request, response, start_ms
)
return body
async def get_file(
self,
destination: str,
path: str,
output_stream,
args: Optional[QueryArgs] = None,
retry_on_dns_fail: bool = True,
max_size: Optional[int] = None,
ignore_backoff: bool = False,
) -> Tuple[int, Dict[bytes, List[bytes]]]:
"""GETs a file from a given homeserver
Args:
destination: The remote server to send the HTTP request to.
path: The HTTP path to GET.
output_stream: File to write the response body to.
args: Optional dictionary used to create the query string.
ignore_backoff: true to ignore the historical backoff data
and try the request anyway.
Returns:
Resolves with an (int,dict) tuple of
the file length and a dict of the response headers.
Raises:
HttpResponseException: If we get an HTTP response code >= 300
(except 429).
NotRetryingDestination: If we are not yet ready to retry this
server.
FederationDeniedError: If this destination is not on our
federation whitelist
RequestSendFailed: If there were problems connecting to the
remote, due to e.g. DNS failures, connection timeouts etc.
"""
request = MatrixFederationRequest(
method="GET", destination=destination, path=path, query=args
)
response = await self._send_request(
request, retry_on_dns_fail=retry_on_dns_fail, ignore_backoff=ignore_backoff
)
headers = dict(response.headers.getAllRawHeaders())
try:
d = read_body_with_max_size(response, output_stream, max_size)
d.addTimeout(self.default_timeout, self.reactor)
length = await make_deferred_yieldable(d)
except BodyExceededMaxSize:
msg = "Requested file is too large > %r bytes" % (max_size,)
logger.warning(
"{%s} [%s] %s",
request.txn_id,
request.destination,
msg,
)
raise SynapseError(502, msg, Codes.TOO_LARGE)
except Exception as e:
logger.warning(
"{%s} [%s] Error reading response: %s",
request.txn_id,
request.destination,
e,
)
raise
logger.info(
"{%s} [%s] Completed: %d %s [%d bytes] %s %s",
request.txn_id,
request.destination,
response.code,
response.phrase.decode("ascii", errors="replace"),
length,
request.method,
request.uri.decode("ascii"),
)
return (length, headers)
def _flatten_response_never_received(e):
if hasattr(e, "reasons"):
reasons = ", ".join(
_flatten_response_never_received(f.value) for f in e.reasons
)
return "%s:[%s]" % (type(e).__name__, reasons)
else:
return repr(e)
def check_content_type_is_json(headers: Headers) -> None:
"""
Check that a set of HTTP headers have a Content-Type header, and that it
is application/json.
Args:
headers: headers to check
Raises:
RequestSendFailed: if the Content-Type header is missing or isn't JSON
"""
content_type_headers = headers.getRawHeaders(b"Content-Type")
if content_type_headers is None:
raise RequestSendFailed(
RuntimeError("No Content-Type header received from remote server"),
can_retry=False,
)
c_type = content_type_headers[0].decode("ascii") # only the first header
val, options = cgi.parse_header(c_type)
if val != "application/json":
raise RequestSendFailed(
RuntimeError(
"Remote server sent Content-Type header of '%s', not 'application/json'"
% c_type,
),
can_retry=False,
)