diff options
Diffstat (limited to 'netlib/http2/protocol.py')
| -rw-r--r-- | netlib/http2/protocol.py | 160 |
1 files changed, 119 insertions, 41 deletions
diff --git a/netlib/http2/protocol.py b/netlib/http2/protocol.py index feac220c..ac89bac4 100644 --- a/netlib/http2/protocol.py +++ b/netlib/http2/protocol.py @@ -26,72 +26,106 @@ class HTTP2Protocol(object): ) # "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n" - CLIENT_CONNECTION_PREFACE = '505249202a20485454502f322e300d0a0d0a534d0d0a0d0a' + CLIENT_CONNECTION_PREFACE =\ + '505249202a20485454502f322e300d0a0d0a534d0d0a0d0a'.decode('hex') ALPN_PROTO_H2 = 'h2' - def __init__(self, tcp_client): - self.tcp_client = tcp_client + def __init__(self, tcp_handler, is_server=False, dump_frames=False): + self.tcp_handler = tcp_handler + self.is_server = is_server self.http2_settings = frame.HTTP2_DEFAULT_SETTINGS.copy() self.current_stream_id = None self.encoder = Encoder() self.decoder = Decoder() + self.connection_preface_performed = False + self.dump_frames = dump_frames def check_alpn(self): - alp = self.tcp_client.get_alpn_proto_negotiated() + alp = self.tcp_handler.get_alpn_proto_negotiated() if alp != self.ALPN_PROTO_H2: raise NotImplementedError( "HTTP2Protocol can not handle unknown ALP: %s" % alp) return True - def perform_connection_preface(self): - self.tcp_client.wfile.write( - bytes(self.CLIENT_CONNECTION_PREFACE.decode('hex'))) - self.send_frame(frame.SettingsFrame(state=self)) + def _receive_settings(self, hide=False): + while True: + frm = self.read_frame(hide) + if isinstance(frm, frame.SettingsFrame): + break + + def _read_settings_ack(self, hide=False): # pragma no cover + while True: + frm = self.read_frame(hide) + if isinstance(frm, frame.SettingsFrame): + assert settings_ack_frame.flags & frame.Frame.FLAG_ACK + assert len(settings_ack_frame.settings) == 0 + break + + def perform_server_connection_preface(self, force=False): + if force or not self.connection_preface_performed: + self.connection_preface_performed = True - # read server settings frame - frm = frame.Frame.from_file(self.tcp_client.rfile, self) - assert isinstance(frm, frame.SettingsFrame) - self._apply_settings(frm.settings) + magic_length = len(self.CLIENT_CONNECTION_PREFACE) + magic = self.tcp_handler.rfile.safe_read(magic_length) + assert magic == self.CLIENT_CONNECTION_PREFACE - # read setting ACK frame - settings_ack_frame = self.read_frame() - assert isinstance(settings_ack_frame, frame.SettingsFrame) - assert settings_ack_frame.flags & frame.Frame.FLAG_ACK - assert len(settings_ack_frame.settings) == 0 + self.send_frame(frame.SettingsFrame(state=self), hide=True) + self._receive_settings(hide=True) + + def perform_client_connection_preface(self, force=False): + if force or not self.connection_preface_performed: + self.connection_preface_performed = True + + self.tcp_handler.wfile.write(self.CLIENT_CONNECTION_PREFACE) + + self.send_frame(frame.SettingsFrame(state=self), hide=True) + self._receive_settings(hide=True) def next_stream_id(self): if self.current_stream_id is None: - self.current_stream_id = 1 + if self.is_server: + # servers must use even stream ids + self.current_stream_id = 2 + else: + # clients must use odd stream ids + self.current_stream_id = 1 else: self.current_stream_id += 2 return self.current_stream_id - def send_frame(self, frame): - raw_bytes = frame.to_bytes() - self.tcp_client.wfile.write(raw_bytes) - self.tcp_client.wfile.flush() + def send_frame(self, frm, hide=False): + raw_bytes = frm.to_bytes() + self.tcp_handler.wfile.write(raw_bytes) + self.tcp_handler.wfile.flush() + if not hide and self.dump_frames: # pragma no cover + print(frm.human_readable(">>")) - def read_frame(self): - frm = frame.Frame.from_file(self.tcp_client.rfile, self) - if isinstance(frm, frame.SettingsFrame): - self._apply_settings(frm.settings) + def read_frame(self, hide=False): + frm = frame.Frame.from_file(self.tcp_handler.rfile, self) + if not hide and self.dump_frames: # pragma no cover + print(frm.human_readable("<<")) + if isinstance(frm, frame.SettingsFrame) and not frm.flags & frame.Frame.FLAG_ACK: + self._apply_settings(frm.settings, hide) return frm - def _apply_settings(self, settings): + def _apply_settings(self, settings, hide=False): for setting, value in settings.items(): old_value = self.http2_settings[setting] if not old_value: old_value = '-' - self.http2_settings[setting] = value self.send_frame( frame.SettingsFrame( state=self, - flags=frame.Frame.FLAG_ACK)) + flags=frame.Frame.FLAG_ACK), + hide) + + # be liberal in what we expect from the other end + # to be more strict use: self._read_settings_ack(hide) def _create_headers(self, headers, stream_id, end_stream=True): # TODO: implement max frame size checks and sending in chunks @@ -102,12 +136,16 @@ class HTTP2Protocol(object): header_block_fragment = self.encoder.encode(headers) - bytes = frame.HeadersFrame( + frm = frame.HeadersFrame( state=self, flags=flags, stream_id=stream_id, - header_block_fragment=header_block_fragment).to_bytes() - return [bytes] + header_block_fragment=header_block_fragment) + + if self.dump_frames: # pragma no cover + print(frm.human_readable(">>")) + + return [frm.to_bytes()] def _create_body(self, body, stream_id): if body is None or len(body) == 0: @@ -116,21 +154,32 @@ class HTTP2Protocol(object): # TODO: implement max frame size checks and sending in chunks # TODO: implement flow-control window - bytes = frame.DataFrame( + frm = frame.DataFrame( state=self, flags=frame.Frame.FLAG_END_STREAM, stream_id=stream_id, - payload=body).to_bytes() - return [bytes] + payload=body) + + if self.dump_frames: # pragma no cover + print(frm.human_readable(">>")) + + return [frm.to_bytes()] + def create_request(self, method, path, headers=None, body=None): if headers is None: headers = [] + authority = self.tcp_handler.sni if self.tcp_handler.sni else self.tcp_handler.address.host + if self.tcp_handler.address.port != 443: + authority += ":%d" % self.tcp_handler.address.port + headers = [ (b':method', bytes(method)), (b':path', bytes(path)), - (b':scheme', b'https')] + headers + (b':scheme', b'https'), + (b':authority', authority), + ] + headers stream_id = self.next_stream_id() @@ -139,25 +188,54 @@ class HTTP2Protocol(object): self._create_body(body, stream_id))) def read_response(self): + stream_id, headers, body = self._receive_transmission() + return headers[':status'], headers, body + + def read_request(self): + return self._receive_transmission() + + def _receive_transmission(self): + body_expected = True + + stream_id = 0 header_block_fragment = b'' body = b'' while True: frm = self.read_frame() - if isinstance(frm, frame.HeadersFrame): + if isinstance(frm, frame.HeadersFrame)\ + or isinstance(frm, frame.ContinuationFrame): + stream_id = frm.stream_id header_block_fragment += frm.header_block_fragment - if frm.flags | frame.Frame.FLAG_END_HEADERS: + if frm.flags & frame.Frame.FLAG_END_STREAM: + body_expected = False + if frm.flags & frame.Frame.FLAG_END_HEADERS: break - while True: + while body_expected: frm = self.read_frame() if isinstance(frm, frame.DataFrame): body += frm.payload - if frm.flags | frame.Frame.FLAG_END_STREAM: + if frm.flags & frame.Frame.FLAG_END_STREAM: break + # TODO: implement window update & flow headers = {} for header, value in self.decoder.decode(header_block_fragment): headers[header] = value - return headers[':status'], headers, body + return stream_id, headers, body + + def create_response(self, code, stream_id=None, headers=None, body=None): + if headers is None: + headers = [] + + headers = [(b':status', bytes(str(code)))] + headers + + if not stream_id: + stream_id = self.next_stream_id() + + return list(itertools.chain( + self._create_headers(headers, stream_id, end_stream=(body is None)), + self._create_body(body, stream_id), + )) |