diff options
Diffstat (limited to 'netlib/http2/__init__.py')
| -rw-r--r-- | netlib/http2/__init__.py | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/netlib/http2/__init__.py b/netlib/http2/__init__.py new file mode 100644 index 00000000..d6f2c51c --- /dev/null +++ b/netlib/http2/__init__.py @@ -0,0 +1,181 @@ +from __future__ import (absolute_import, print_function, division) +import itertools +import logging + +from .frame import * +from .. import utils + +log = logging.getLogger(__name__) + + +class HTTP2Protocol(object): + + ERROR_CODES = utils.BiDi( + NO_ERROR=0x0, + PROTOCOL_ERROR=0x1, + INTERNAL_ERROR=0x2, + FLOW_CONTROL_ERROR=0x3, + SETTINGS_TIMEOUT=0x4, + STREAM_CLOSED=0x5, + FRAME_SIZE_ERROR=0x6, + REFUSED_STREAM=0x7, + CANCEL=0x8, + COMPRESSION_ERROR=0x9, + CONNECT_ERROR=0xa, + ENHANCE_YOUR_CALM=0xb, + INADEQUATE_SECURITY=0xc, + HTTP_1_1_REQUIRED=0xd + ) + + # "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n" + CLIENT_CONNECTION_PREFACE = '505249202a20485454502f322e300d0a0d0a534d0d0a0d0a' + + ALPN_PROTO_H2 = b'h2' + + HTTP2_DEFAULT_SETTINGS = { + SettingsFrame.SETTINGS.SETTINGS_HEADER_TABLE_SIZE: 4096, + SettingsFrame.SETTINGS.SETTINGS_ENABLE_PUSH: 1, + SettingsFrame.SETTINGS.SETTINGS_MAX_CONCURRENT_STREAMS: None, + SettingsFrame.SETTINGS.SETTINGS_INITIAL_WINDOW_SIZE: 2 ** 16 - 1, + SettingsFrame.SETTINGS.SETTINGS_MAX_FRAME_SIZE: 2 ** 14, + SettingsFrame.SETTINGS.SETTINGS_MAX_HEADER_LIST_SIZE: None, + } + + def __init__(self, tcp_client): + self.tcp_client = tcp_client + + self.http2_settings = self.HTTP2_DEFAULT_SETTINGS.copy() + self.current_stream_id = None + self.encoder = Encoder() + self.decoder = Decoder() + + def check_alpn(self): + alp = self.tcp_client.get_alpn_proto_negotiated() + if alp != self.ALPN_PROTO_H2: + raise NotImplementedError( + "H2Client can not handle unknown ALP: %s" % alp) + log.debug("ALP 'h2' successfully negotiated.") + + def send_connection_preface(self): + self.tcp_client.wfile.write( + bytes(self.CLIENT_CONNECTION_PREFACE.decode('hex'))) + self.send_frame(SettingsFrame(state=self)) + + frame = Frame.from_file(self.tcp_client.rfile, self) + assert isinstance(frame, SettingsFrame) + self._apply_settings(frame.settings) + self.read_frame() # read setting ACK frame + + log.debug("Connection Preface completed.") + + def next_stream_id(self): + if self.current_stream_id is None: + 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 read_frame(self): + frame = Frame.from_file(self.tcp_client.rfile, self) + if isinstance(frame, SettingsFrame): + self._apply_settings(frame.settings) + + return frame + + def _apply_settings(self, settings): + for setting, value in settings.items(): + old_value = self.http2_settings[setting] + if not old_value: + old_value = '-' + + self.http2_settings[setting] = value + log.debug("Setting changed: %s to %d (was %s)" % ( + SettingsFrame.SETTINGS.get_name(setting), + value, + str(old_value))) + + self.send_frame(SettingsFrame(state=self, flags=Frame.FLAG_ACK)) + log.debug("New settings acknowledged.") + + def _create_headers(self, headers, stream_id, end_stream=True): + # TODO: implement max frame size checks and sending in chunks + + flags = Frame.FLAG_END_HEADERS + if end_stream: + flags |= Frame.FLAG_END_STREAM + + header_block_fragment = self.encoder.encode(headers) + + bytes = HeadersFrame( + state=self, + flags=flags, + stream_id=stream_id, + header_block_fragment=header_block_fragment).to_bytes() + return [bytes] + + def _create_body(self, body, stream_id): + if body is None or len(body) == 0: + return b'' + + # TODO: implement max frame size checks and sending in chunks + # TODO: implement flow-control window + + bytes = DataFrame( + state=self, + flags=Frame.FLAG_END_STREAM, + stream_id=stream_id, + payload=body).to_bytes() + return [bytes] + + def create_request(self, method, path, headers=None, body=None): + if headers is None: + headers = [] + + headers = [ + (b':method', bytes(method)), + (b':path', bytes(path)), + (b':scheme', b'https')] + headers + + 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))) + + def read_response(self): + header_block_fragment = b'' + body = b'' + + while True: + frame = self.read_frame() + if isinstance(frame, HeadersFrame): + header_block_fragment += frame.header_block_fragment + if frame.flags | Frame.FLAG_END_HEADERS: + break + else: + log.debug("Unexpected frame received:") + log.debug(frame.human_readable()) + + while True: + frame = self.read_frame() + if isinstance(frame, DataFrame): + body += frame.payload + if frame.flags | Frame.FLAG_END_STREAM: + break + else: + log.debug("Unexpected frame received:") + log.debug(frame.human_readable()) + + headers = {} + for header, value in self.decoder.decode(header_block_fragment): + headers[header] = value + + for header, value in headers.items(): + log.debug("%s: %s" % (header, value)) + + return headers[':status'], headers, body |