mitmproxy/netlib/http/http2/protocol.py
2015-07-30 19:40:00 +02:00

336 lines
11 KiB
Python

from __future__ import (absolute_import, print_function, division)
import itertools
import time
from hpack.hpack import Encoder, Decoder
from netlib import http, utils, odict
from netlib.http import semantics
from . import frame
class TCPHandler(object):
def __init__(self, rfile, wfile=None):
self.rfile = rfile
self.wfile = wfile
class HTTP2Protocol(semantics.ProtocolMixin):
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'.decode('hex')
ALPN_PROTO_H2 = 'h2'
def __init__(
self,
tcp_handler=None,
rfile=None,
wfile=None,
is_server=False,
dump_frames=False,
encoder=None,
decoder=None,
):
self.tcp_handler = tcp_handler or TCPHandler(rfile, wfile)
self.is_server = is_server
self.dump_frames = dump_frames
self.encoder = encoder or Encoder()
self.decoder = decoder or Decoder()
self.http2_settings = frame.HTTP2_DEFAULT_SETTINGS.copy()
self.current_stream_id = None
self.connection_preface_performed = False
def read_request(self, include_body=True, body_size_limit=None, allow_empty=False):
self.perform_connection_preface()
timestamp_start = time.time()
if hasattr(self.tcp_handler.rfile, "reset_timestamps"):
self.tcp_handler.rfile.reset_timestamps()
stream_id, headers, body = self._receive_transmission(include_body)
if hasattr(self.tcp_handler.rfile, "first_byte_timestamp"):
# more accurate timestamp_start
timestamp_start = self.tcp_handler.rfile.first_byte_timestamp
timestamp_end = time.time()
request = http.Request(
"relative", # TODO: use the correct value
headers.get_first(':method', 'GET'),
headers.get_first(':scheme', 'https'),
headers.get_first(':host', 'localhost'),
443, # TODO: parse port number from host?
headers.get_first(':path', '/'),
(2, 0),
headers,
body,
timestamp_start,
timestamp_end,
)
request.stream_id = stream_id
return request
def read_response(self, request_method='', body_size_limit=None, include_body=True):
self.perform_connection_preface()
timestamp_start = time.time()
if hasattr(self.tcp_handler.rfile, "reset_timestamps"):
self.tcp_handler.rfile.reset_timestamps()
stream_id, headers, body = self._receive_transmission(include_body)
if hasattr(self.tcp_handler.rfile, "first_byte_timestamp"):
# more accurate timestamp_start
timestamp_start = self.tcp_handler.rfile.first_byte_timestamp
if include_body:
timestamp_end = time.time()
else:
timestamp_end = None
response = http.Response(
(2, 0),
int(headers.get_first(':status')),
"",
headers,
body,
timestamp_start=timestamp_start,
timestamp_end=timestamp_end,
)
response.stream_id = stream_id
return response
def assemble_request(self, request):
assert isinstance(request, semantics.Request)
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 = request.headers.copy()
if not ':authority' in headers.keys():
headers.add(':authority', bytes(authority), prepend=True)
if not ':scheme' in headers.keys():
headers.add(':scheme', bytes(request.scheme), prepend=True)
if not ':path' in headers.keys():
headers.add(':path', bytes(request.path), prepend=True)
if not ':method' in headers.keys():
headers.add(':method', bytes(request.method), prepend=True)
headers = headers.items()
if hasattr(request, 'stream_id'):
stream_id = request.stream_id
else:
stream_id = self._next_stream_id()
return list(itertools.chain(
self._create_headers(headers, stream_id, end_stream=(request.body is None or len(request.body) == 0)),
self._create_body(request.body, stream_id)))
def assemble_response(self, response):
assert isinstance(response, semantics.Response)
headers = response.headers.copy()
if not ':status' in headers.keys():
headers.add(':status', bytes(str(response.status_code)), prepend=True)
headers = headers.items()
if hasattr(response, 'stream_id'):
stream_id = response.stream_id
else:
stream_id = self._next_stream_id()
return list(itertools.chain(
self._create_headers(headers, stream_id, end_stream=(response.body is None or len(response.body) == 0)),
self._create_body(response.body, stream_id),
))
def perform_connection_preface(self, force=False):
if force or not self.connection_preface_performed:
if self.is_server:
self.perform_server_connection_preface(force)
else:
self.perform_client_connection_preface(force)
def perform_server_connection_preface(self, force=False):
if force or not self.connection_preface_performed:
self.connection_preface_performed = True
magic_length = len(self.CLIENT_CONNECTION_PREFACE)
magic = self.tcp_handler.rfile.safe_read(magic_length)
assert magic == self.CLIENT_CONNECTION_PREFACE
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 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, 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 check_alpn(self):
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 _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 frm.flags & frame.Frame.FLAG_ACK
assert len(frm.settings) == 0
break
def _next_stream_id(self):
if self.current_stream_id is None:
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 _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
frm = frame.SettingsFrame(
state=self,
flags=frame.Frame.FLAG_ACK)
self.send_frame(frm, 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
flags = frame.Frame.FLAG_END_HEADERS
if end_stream:
flags |= frame.Frame.FLAG_END_STREAM
header_block_fragment = self.encoder.encode(headers)
frm = frame.HeadersFrame(
state=self,
flags=flags,
stream_id=stream_id,
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:
return b''
# TODO: implement max frame size checks and sending in chunks
# TODO: implement flow-control window
frm = frame.DataFrame(
state=self,
flags=frame.Frame.FLAG_END_STREAM,
stream_id=stream_id,
payload=body)
if self.dump_frames: # pragma no cover
print(frm.human_readable(">>"))
return [frm.to_bytes()]
def _receive_transmission(self, include_body=True):
body_expected = True
stream_id = 0
header_block_fragment = b''
body = b''
while True:
frm = self.read_frame()
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_STREAM:
body_expected = False
if frm.flags & frame.Frame.FLAG_END_HEADERS:
break
while body_expected:
frm = self.read_frame()
if isinstance(frm, frame.DataFrame):
body += frm.payload
if frm.flags & frame.Frame.FLAG_END_STREAM:
break
# TODO: implement window update & flow
headers = odict.ODictCaseless()
for header, value in self.decoder.decode(header_block_fragment):
headers.add(header, value)
return stream_id, headers, body