diff options
Diffstat (limited to 'libmproxy/protocol/http2.py')
| -rw-r--r-- | libmproxy/protocol/http2.py | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/libmproxy/protocol/http2.py b/libmproxy/protocol/http2.py new file mode 100644 index 00000000..a6d1b73f --- /dev/null +++ b/libmproxy/protocol/http2.py @@ -0,0 +1,365 @@ +from __future__ import (absolute_import, print_function, division) + +import struct +import threading +import time +import Queue + +from netlib.tcp import ssl_read_select +from netlib.exceptions import HttpException +from netlib.http import Headers + +import h2 +from h2.connection import H2Connection +from h2.events import * + +from .base import Layer +from .http import _HttpTransmissionLayer, HttpLayer +from .. import utils +from ..models import HTTPRequest, HTTPResponse + + +class SafeH2Connection(H2Connection): + def __init__(self, conn, *args, **kwargs): + super(SafeH2Connection, self).__init__(*args, **kwargs) + self.conn = conn + self.lock = threading.RLock() + + def safe_close_connection(self, error_code): + with self.lock: + self.close_connection(error_code) + self.conn.send(self.data_to_send()) + + def safe_increment_flow_control(self, stream_id, length): + if length == 0: + return + + with self.lock: + self.increment_flow_control_window(length) + self.conn.send(self.data_to_send()) + with self.lock: + if stream_id in self.streams and not self.streams[stream_id].closed: + self.increment_flow_control_window(length, stream_id=stream_id) + self.conn.send(self.data_to_send()) + + def safe_reset_stream(self, stream_id, error_code): + with self.lock: + try: + self.reset_stream(stream_id, error_code) + except h2.exceptions.StreamClosedError: + # stream is already closed - good + pass + self.conn.send(self.data_to_send()) + + def safe_update_settings(self, new_settings): + with self.lock: + self.update_settings(new_settings) + self.conn.send(self.data_to_send()) + + def safe_send_headers(self, is_zombie, stream_id, headers): + with self.lock: + if is_zombie(self, stream_id): + return + self.send_headers(stream_id, headers) + self.conn.send(self.data_to_send()) + + def safe_send_body(self, is_zombie, stream_id, chunks): + for chunk in chunks: + position = 0 + while position < len(chunk): + self.lock.acquire() + if is_zombie(self, stream_id): + return + max_outbound_frame_size = self.max_outbound_frame_size + frame_chunk = chunk[position:position+max_outbound_frame_size] + if self.local_flow_control_window(stream_id) < len(frame_chunk): + self.lock.release() + time.sleep(0) + continue + self.send_data(stream_id, frame_chunk) + self.conn.send(self.data_to_send()) + self.lock.release() + position += max_outbound_frame_size + with self.lock: + if is_zombie(self, stream_id): + return + self.end_stream(stream_id) + self.conn.send(self.data_to_send()) + + +class Http2Layer(Layer): + def __init__(self, ctx, mode): + super(Http2Layer, self).__init__(ctx) + self.mode = mode + self.streams = dict() + self.server_to_client_stream_ids = dict([(0, 0)]) + self.client_conn.h2 = SafeH2Connection(self.client_conn, client_side=False) + + # make sure that we only pass actual SSL.Connection objects in here, + # because otherwise ssl_read_select fails! + self.active_conns = [self.client_conn.connection] + + def _initiate_server_conn(self): + self.server_conn.h2 = SafeH2Connection(self.server_conn, client_side=True) + self.server_conn.h2.initiate_connection() + self.server_conn.send(self.server_conn.h2.data_to_send()) + self.active_conns.append(self.server_conn.connection) + + def connect(self): + self.ctx.connect() + self.server_conn.connect() + self._initiate_server_conn() + + def set_server(self): + raise NotImplementedError("Cannot change server for HTTP2 connections.") + + def disconnect(self): + raise NotImplementedError("Cannot dis- or reconnect in HTTP2 connections.") + + def next_layer(self): + # WebSockets over HTTP/2? + # CONNECT for proxying? + raise NotImplementedError() + + def _handle_event(self, event, source_conn, other_conn, is_server): + if hasattr(event, 'stream_id'): + if is_server and event.stream_id % 2 == 1: + eid = self.server_to_client_stream_ids[event.stream_id] + else: + eid = event.stream_id + + if isinstance(event, RequestReceived): + headers = Headers([[str(k), str(v)] for k, v in event.headers]) + self.streams[eid] = Http2SingleStreamLayer(self, eid, headers) + self.streams[eid].timestamp_start = time.time() + self.streams[eid].start() + elif isinstance(event, ResponseReceived): + headers = Headers([[str(k), str(v)] for k, v in event.headers]) + self.streams[eid].queued_data_length = 0 + self.streams[eid].timestamp_start = time.time() + self.streams[eid].response_headers = headers + self.streams[eid].response_arrived.set() + elif isinstance(event, DataReceived): + if self.config.body_size_limit and self.streams[eid].queued_data_length > self.config.body_size_limit: + raise HttpException("HTTP body too large. Limit is {}.".format(self.config.body_size_limit)) + self.streams[eid].data_queue.put(event.data) + self.streams[eid].queued_data_length += len(event.data) + source_conn.h2.safe_increment_flow_control(event.stream_id, len(event.data)) + elif isinstance(event, StreamEnded): + self.streams[eid].timestamp_end = time.time() + self.streams[eid].data_finished.set() + elif isinstance(event, StreamReset): + self.streams[eid].zombie = time.time() + if eid in self.streams and event.error_code == 0x8: + if is_server: + other_stream_id = self.streams[eid].client_stream_id + else: + other_stream_id = self.streams[eid].server_stream_id + other_conn.h2.safe_reset_stream(other_stream_id, event.error_code) + elif isinstance(event, RemoteSettingsChanged): + new_settings = dict([(id, cs.new_value) for (id, cs) in event.changed_settings.iteritems()]) + other_conn.h2.safe_update_settings(new_settings) + elif isinstance(event, ConnectionTerminated): + other_conn.h2.safe_close_connection(event.error_code) + return False + elif isinstance(event, PushedStreamReceived): + # pushed stream ids should be uniq and not dependent on race conditions + # only the parent stream id must be looked up first + parent_eid = self.server_to_client_stream_ids[event.parent_stream_id] + with self.client_conn.h2.lock: + self.client_conn.h2.push_stream(parent_eid, event.pushed_stream_id, event.headers) + + headers = Headers([[str(k), str(v)] for k, v in event.headers]) + headers['x-mitmproxy-pushed'] = 'true' + self.streams[event.pushed_stream_id] = Http2SingleStreamLayer(self, event.pushed_stream_id, headers) + self.streams[event.pushed_stream_id].timestamp_start = time.time() + self.streams[event.pushed_stream_id].pushed = True + self.streams[event.pushed_stream_id].parent_stream_id = parent_eid + self.streams[event.pushed_stream_id].timestamp_end = time.time() + self.streams[event.pushed_stream_id].data_finished.set() + self.streams[event.pushed_stream_id].start() + elif isinstance(event, TrailersReceived): + raise NotImplementedError() + + return True + + def _cleanup_streams(self): + death_time = time.time() - 10 + for stream_id in self.streams.keys(): + zombie = self.streams[stream_id].zombie + if zombie and zombie <= death_time: + self.streams.pop(stream_id, None) + + def __call__(self): + if self.server_conn: + self._initiate_server_conn() + + preamble = self.client_conn.rfile.read(24) + self.client_conn.h2.initiate_connection() + self.client_conn.h2.receive_data(preamble) + self.client_conn.send(self.client_conn.h2.data_to_send()) + + while True: + r = ssl_read_select(self.active_conns, 1) + for conn in r: + source_conn = self.client_conn if conn == self.client_conn.connection else self.server_conn + other_conn = self.server_conn if conn == self.client_conn.connection else self.client_conn + is_server = (conn == self.server_conn.connection) + + field = source_conn.rfile.peek(3) + length = int(field.encode('hex'), 16) + raw_frame = source_conn.rfile.safe_read(9 + length) + + with source_conn.h2.lock: + events = source_conn.h2.receive_data(raw_frame) + source_conn.send(source_conn.h2.data_to_send()) + + for event in events: + if not self._handle_event(event, source_conn, other_conn, is_server): + return + + self._cleanup_streams() + + +class Http2SingleStreamLayer(_HttpTransmissionLayer, threading.Thread): + def __init__(self, ctx, stream_id, request_headers): + super(Http2SingleStreamLayer, self).__init__(ctx) + self.zombie = None + self.client_stream_id = stream_id + self.server_stream_id = None + self.request_headers = request_headers + self.response_headers = None + self.data_queue = Queue.Queue() + self.queued_data_length = 0 + + self.response_arrived = threading.Event() + self.data_finished = threading.Event() + + def is_zombie(self, h2_conn, stream_id): + if self.zombie: + return True + return False + + def read_request(self): + self.data_finished.wait() + self.data_finished.clear() + + authority = self.request_headers.get(':authority', '') + method = self.request_headers.get(':method', 'GET') + scheme = self.request_headers.get(':scheme', 'https') + path = self.request_headers.get(':path', '/') + host = None + port = None + + if path == '*' or path.startswith("/"): + form_in = "relative" + elif method == 'CONNECT': + form_in = "authority" + if ":" in authority: + host, port = authority.split(":", 1) + else: + host = authority + else: + form_in = "absolute" + # FIXME: verify if path or :host contains what we need + scheme, host, port, _ = utils.parse_url(path) + + if host is None: + host = 'localhost' + if port is None: + port = 80 if scheme == 'http' else 443 + port = int(port) + + data = [] + while self.data_queue.qsize() > 0: + data.append(self.data_queue.get()) + data = b"".join(data) + + return HTTPRequest( + form_in, + method, + scheme, + host, + port, + path, + (2, 0), + self.request_headers, + data, + timestamp_start=self.timestamp_start, + timestamp_end=self.timestamp_end, + ) + + def send_request(self, message): + with self.server_conn.h2.lock: + self.server_stream_id = self.server_conn.h2.get_next_available_stream_id() + self.server_to_client_stream_ids[self.server_stream_id] = self.client_stream_id + + self.server_conn.h2.safe_send_headers( + self.is_zombie, + self.server_stream_id, + message.headers + ) + self.server_conn.h2.safe_send_body( + self.is_zombie, + self.server_stream_id, + message.body + ) + + def read_response_headers(self): + self.response_arrived.wait() + + status_code = int(self.response_headers.get(':status', 502)) + + return HTTPResponse( + http_version=(2, 0), + status_code=status_code, + reason='', + headers=self.response_headers, + content=None, + timestamp_start=self.timestamp_start, + timestamp_end=self.timestamp_end, + ) + + def read_response_body(self, request, response): + while True: + try: + yield self.data_queue.get(timeout=1) + except Queue.Empty: + pass + if self.data_finished.is_set(): + while self.data_queue.qsize() > 0: + yield self.data_queue.get() + return + if self.zombie: + return + + def send_response_headers(self, response): + self.client_conn.h2.safe_send_headers( + self.is_zombie, + self.client_stream_id, + response.headers + ) + + def send_response_body(self, _response, chunks): + self.client_conn.h2.safe_send_body( + self.is_zombie, + self.client_stream_id, + chunks + ) + + def check_close_connection(self, flow): + # This layer only handles a single stream. + # RFC 7540 8.1: An HTTP request/response exchange fully consumes a single stream. + return True + + def connect(self): + raise ValueError("CONNECT inside an HTTP2 stream is not supported.") + + def set_server(self, *args, **kwargs): + # do not mess with the server connection - all streams share it. + pass + + def run(self): + layer = HttpLayer(self, self.mode) + layer() + self.zombie = time.time() |