From f003f87197a6dffe1b51a82f7dd218121c75e206 Mon Sep 17 00:00:00 2001 From: Thomas Kriechbaumer Date: Thu, 4 Jun 2015 19:44:48 +0200 Subject: http2: rename module and refactor as strategy --- netlib/h2/__init__.py | 178 -------------- netlib/h2/frame.py | 623 ---------------------------------------------- netlib/http2/__init__.py | 181 ++++++++++++++ netlib/http2/frame.py | 625 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 806 insertions(+), 801 deletions(-) delete mode 100644 netlib/h2/__init__.py delete mode 100644 netlib/h2/frame.py create mode 100644 netlib/http2/__init__.py create mode 100644 netlib/http2/frame.py (limited to 'netlib') diff --git a/netlib/h2/__init__.py b/netlib/h2/__init__.py deleted file mode 100644 index c06f7a11..00000000 --- a/netlib/h2/__init__.py +++ /dev/null @@ -1,178 +0,0 @@ -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): - 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.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.wfile.write(bytes(self.CLIENT_CONNECTION_PREFACE.decode('hex'))) - self.send_frame(SettingsFrame(state=self)) - - frame = Frame.from_file(self.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.wfile.write(raw_bytes) - self.wfile.flush() - - def read_frame(self): - frame = Frame.from_file(self.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 diff --git a/netlib/h2/frame.py b/netlib/h2/frame.py deleted file mode 100644 index 018e822f..00000000 --- a/netlib/h2/frame.py +++ /dev/null @@ -1,623 +0,0 @@ -import struct -import logging -from functools import reduce -from hpack.hpack import Encoder, Decoder - -from .. import utils - -log = logging.getLogger(__name__) - -class FrameSizeError(Exception): - pass - -class Frame(object): - - """ - Baseclass Frame - contains header - payload is defined in subclasses - """ - - FLAG_NO_FLAGS = 0x0 - FLAG_ACK = 0x1 - FLAG_END_STREAM = 0x1 - FLAG_END_HEADERS = 0x4 - FLAG_PADDED = 0x8 - FLAG_PRIORITY = 0x20 - - def __init__( - self, - state=None, - length=0, - flags=FLAG_NO_FLAGS, - stream_id=0x0): - valid_flags = reduce(lambda x, y: x | y, self.VALID_FLAGS, 0x0) - if flags | valid_flags != valid_flags: - raise ValueError('invalid flags detected.') - - if state is None: - from . import HTTP2Protocol - - class State(object): - pass - - state = State() - state.http2_settings = HTTP2Protocol.HTTP2_DEFAULT_SETTINGS.copy() - state.encoder = Encoder() - state.decoder = Decoder() - - self.state = state - - self.length = length - self.type = self.TYPE - self.flags = flags - self.stream_id = stream_id - - @classmethod - def _check_frame_size(self, length, state): - from . import HTTP2Protocol - - if state: - settings = state.http2_settings - else: - settings = HTTP2Protocol.HTTP2_DEFAULT_SETTINGS - - max_frame_size = settings[ - SettingsFrame.SETTINGS.SETTINGS_MAX_FRAME_SIZE] - - if length > max_frame_size: - raise FrameSizeError( - "Frame size exceeded: %d, but only %d allowed." % ( - length, max_frame_size)) - - @classmethod - def from_file(self, fp, state=None): - """ - read a HTTP/2 frame sent by a server or client - fp is a "file like" object that could be backed by a network - stream or a disk or an in memory stream reader - """ - raw_header = fp.safe_read(9) - - fields = struct.unpack("!HBBBL", raw_header) - length = (fields[0] << 8) + fields[1] - flags = fields[3] - stream_id = fields[4] - - self._check_frame_size(length, state) - - payload = fp.safe_read(length) - return FRAMES[fields[2]].from_bytes( - state, - length, - flags, - stream_id, - payload) - - def to_bytes(self): - payload = self.payload_bytes() - self.length = len(payload) - - self._check_frame_size(self.length, self.state) - - b = struct.pack('!HB', self.length & 0xFFFF00, self.length & 0x0000FF) - b += struct.pack('!B', self.TYPE) - b += struct.pack('!B', self.flags) - b += struct.pack('!L', self.stream_id & 0x7FFFFFFF) - b += payload - - return b - - def payload_bytes(self): # pragma: no cover - raise NotImplementedError() - - def payload_human_readable(self): # pragma: no cover - raise NotImplementedError() - - def human_readable(self): - return "\n".join([ - "============================================================", - "length: %d bytes" % self.length, - "type: %s (%#x)" % (self.__class__.__name__, self.TYPE), - "flags: %#x" % self.flags, - "stream_id: %#x" % self.stream_id, - "------------------------------------------------------------", - self.payload_human_readable(), - "============================================================", - ]) - - def __eq__(self, other): - return self.to_bytes() == other.to_bytes() - - -class DataFrame(Frame): - TYPE = 0x0 - VALID_FLAGS = [Frame.FLAG_END_STREAM, Frame.FLAG_PADDED] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - payload=b'', - pad_length=0): - super(DataFrame, self).__init__(state, length, flags, stream_id) - self.payload = payload - self.pad_length = pad_length - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - - if f.flags & self.FLAG_PADDED: - f.pad_length = struct.unpack('!B', payload[0])[0] - f.payload = payload[1:-f.pad_length] - else: - f.payload = payload - - return f - - def payload_bytes(self): - if self.stream_id == 0x0: - raise ValueError('DATA frames MUST be associated with a stream.') - - b = b'' - if self.flags & self.FLAG_PADDED: - b += struct.pack('!B', self.pad_length) - - b += bytes(self.payload) - - if self.flags & self.FLAG_PADDED: - b += b'\0' * self.pad_length - - return b - - def payload_human_readable(self): - return "payload: %s" % str(self.payload) - - -class HeadersFrame(Frame): - TYPE = 0x1 - VALID_FLAGS = [ - Frame.FLAG_END_STREAM, - Frame.FLAG_END_HEADERS, - Frame.FLAG_PADDED, - Frame.FLAG_PRIORITY] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - header_block_fragment=b'', - pad_length=0, - exclusive=False, - stream_dependency=0x0, - weight=0): - super(HeadersFrame, self).__init__(state, length, flags, stream_id) - - self.header_block_fragment = header_block_fragment - self.pad_length = pad_length - self.exclusive = exclusive - self.stream_dependency = stream_dependency - self.weight = weight - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - - if f.flags & self.FLAG_PADDED: - f.pad_length = struct.unpack('!B', payload[0])[0] - f.header_block_fragment = payload[1:-f.pad_length] - else: - f.header_block_fragment = payload[0:] - - if f.flags & self.FLAG_PRIORITY: - f.stream_dependency, f.weight = struct.unpack( - '!LB', f.header_block_fragment[:5]) - f.exclusive = bool(f.stream_dependency >> 31) - f.stream_dependency &= 0x7FFFFFFF - f.header_block_fragment = f.header_block_fragment[5:] - - return f - - def payload_bytes(self): - if self.stream_id == 0x0: - raise ValueError('HEADERS frames MUST be associated with a stream.') - - b = b'' - if self.flags & self.FLAG_PADDED: - b += struct.pack('!B', self.pad_length) - - if self.flags & self.FLAG_PRIORITY: - b += struct.pack('!LB', - (int(self.exclusive) << 31) | self.stream_dependency, - self.weight) - - b += self.header_block_fragment - - if self.flags & self.FLAG_PADDED: - b += b'\0' * self.pad_length - - return b - - def payload_human_readable(self): - s = [] - - if self.flags & self.FLAG_PRIORITY: - s.append("exclusive: %d" % self.exclusive) - s.append("stream dependency: %#x" % self.stream_dependency) - s.append("weight: %d" % self.weight) - - if self.flags & self.FLAG_PADDED: - s.append("padding: %d" % self.pad_length) - - s.append( - "header_block_fragment: %s" % - self.header_block_fragment.encode('hex')) - - return "\n".join(s) - - -class PriorityFrame(Frame): - TYPE = 0x2 - VALID_FLAGS = [] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - exclusive=False, - stream_dependency=0x0, - weight=0): - super(PriorityFrame, self).__init__(state, length, flags, stream_id) - self.exclusive = exclusive - self.stream_dependency = stream_dependency - self.weight = weight - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - - f.stream_dependency, f.weight = struct.unpack('!LB', payload) - f.exclusive = bool(f.stream_dependency >> 31) - f.stream_dependency &= 0x7FFFFFFF - - return f - - def payload_bytes(self): - if self.stream_id == 0x0: - raise ValueError( - 'PRIORITY frames MUST be associated with a stream.') - - if self.stream_dependency == 0x0: - raise ValueError('stream dependency is invalid.') - - return struct.pack( - '!LB', - (int( - self.exclusive) << 31) | self.stream_dependency, - self.weight) - - def payload_human_readable(self): - s = [] - s.append("exclusive: %d" % self.exclusive) - s.append("stream dependency: %#x" % self.stream_dependency) - s.append("weight: %d" % self.weight) - return "\n".join(s) - - -class RstStreamFrame(Frame): - TYPE = 0x3 - VALID_FLAGS = [] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - error_code=0x0): - super(RstStreamFrame, self).__init__(state, length, flags, stream_id) - self.error_code = error_code - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - f.error_code = struct.unpack('!L', payload)[0] - return f - - def payload_bytes(self): - if self.stream_id == 0x0: - raise ValueError( - 'RST_STREAM frames MUST be associated with a stream.') - - return struct.pack('!L', self.error_code) - - def payload_human_readable(self): - return "error code: %#x" % self.error_code - - -class SettingsFrame(Frame): - TYPE = 0x4 - VALID_FLAGS = [Frame.FLAG_ACK] - - SETTINGS = utils.BiDi( - SETTINGS_HEADER_TABLE_SIZE=0x1, - SETTINGS_ENABLE_PUSH=0x2, - SETTINGS_MAX_CONCURRENT_STREAMS=0x3, - SETTINGS_INITIAL_WINDOW_SIZE=0x4, - SETTINGS_MAX_FRAME_SIZE=0x5, - SETTINGS_MAX_HEADER_LIST_SIZE=0x6, - ) - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - settings=None): - super(SettingsFrame, self).__init__(state, length, flags, stream_id) - - if settings is None: - settings = {} - - self.settings = settings - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - - for i in xrange(0, len(payload), 6): - identifier, value = struct.unpack("!HL", payload[i:i + 6]) - f.settings[identifier] = value - - return f - - def payload_bytes(self): - if self.stream_id != 0x0: - raise ValueError( - 'SETTINGS frames MUST NOT be associated with a stream.') - - b = b'' - for identifier, value in self.settings.items(): - b += struct.pack("!HL", identifier & 0xFF, value) - - return b - - def payload_human_readable(self): - s = [] - - for identifier, value in self.settings.items(): - s.append("%s: %#x" % (self.SETTINGS.get_name(identifier), value)) - - if not s: - return "settings: None" - else: - return "\n".join(s) - - -class PushPromiseFrame(Frame): - TYPE = 0x5 - VALID_FLAGS = [Frame.FLAG_END_HEADERS, Frame.FLAG_PADDED] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - promised_stream=0x0, - header_block_fragment=b'', - pad_length=0): - super(PushPromiseFrame, self).__init__(state, length, flags, stream_id) - self.pad_length = pad_length - self.promised_stream = promised_stream - self.header_block_fragment = header_block_fragment - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - - if f.flags & self.FLAG_PADDED: - f.pad_length, f.promised_stream = struct.unpack('!BL', payload[:5]) - f.header_block_fragment = payload[5:-f.pad_length] - else: - f.promised_stream = int(struct.unpack("!L", payload[:4])[0]) - f.header_block_fragment = payload[4:] - - f.promised_stream &= 0x7FFFFFFF - - return f - - def payload_bytes(self): - if self.stream_id == 0x0: - raise ValueError( - 'PUSH_PROMISE frames MUST be associated with a stream.') - - if self.promised_stream == 0x0: - raise ValueError('Promised stream id not valid.') - - b = b'' - if self.flags & self.FLAG_PADDED: - b += struct.pack('!B', self.pad_length) - - b += struct.pack('!L', self.promised_stream & 0x7FFFFFFF) - b += bytes(self.header_block_fragment) - - if self.flags & self.FLAG_PADDED: - b += b'\0' * self.pad_length - - return b - - def payload_human_readable(self): - s = [] - - if self.flags & self.FLAG_PADDED: - s.append("padding: %d" % self.pad_length) - - s.append("promised stream: %#x" % self.promised_stream) - s.append("header_block_fragment: %s" % str(self.header_block_fragment)) - return "\n".join(s) - - -class PingFrame(Frame): - TYPE = 0x6 - VALID_FLAGS = [Frame.FLAG_ACK] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - payload=b''): - super(PingFrame, self).__init__(state, length, flags, stream_id) - self.payload = payload - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - f.payload = payload - return f - - def payload_bytes(self): - if self.stream_id != 0x0: - raise ValueError( - 'PING frames MUST NOT be associated with a stream.') - - b = self.payload[0:8] - b += b'\0' * (8 - len(b)) - return b - - def payload_human_readable(self): - return "opaque data: %s" % str(self.payload) - - -class GoAwayFrame(Frame): - TYPE = 0x7 - VALID_FLAGS = [] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - last_stream=0x0, - error_code=0x0, - data=b''): - super(GoAwayFrame, self).__init__(state, length, flags, stream_id) - self.last_stream = last_stream - self.error_code = error_code - self.data = data - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - - f.last_stream, f.error_code = struct.unpack("!LL", payload[:8]) - f.last_stream &= 0x7FFFFFFF - f.data = payload[8:] - - return f - - def payload_bytes(self): - if self.stream_id != 0x0: - raise ValueError( - 'GOAWAY frames MUST NOT be associated with a stream.') - - b = struct.pack('!LL', self.last_stream & 0x7FFFFFFF, self.error_code) - b += bytes(self.data) - return b - - def payload_human_readable(self): - s = [] - s.append("last stream: %#x" % self.last_stream) - s.append("error code: %d" % self.error_code) - s.append("debug data: %s" % str(self.data)) - return "\n".join(s) - - -class WindowUpdateFrame(Frame): - TYPE = 0x8 - VALID_FLAGS = [] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - window_size_increment=0x0): - super(WindowUpdateFrame, self).__init__(state, length, flags, stream_id) - self.window_size_increment = window_size_increment - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - - f.window_size_increment = struct.unpack("!L", payload)[0] - f.window_size_increment &= 0x7FFFFFFF - - return f - - def payload_bytes(self): - if self.window_size_increment <= 0 or self.window_size_increment >= 2 ** 31: - raise ValueError( - 'Window Szie Increment MUST be greater than 0 and less than 2^31.') - - return struct.pack('!L', self.window_size_increment & 0x7FFFFFFF) - - def payload_human_readable(self): - return "window size increment: %#x" % self.window_size_increment - - -class ContinuationFrame(Frame): - TYPE = 0x9 - VALID_FLAGS = [Frame.FLAG_END_HEADERS] - - def __init__( - self, - state=None, - length=0, - flags=Frame.FLAG_NO_FLAGS, - stream_id=0x0, - header_block_fragment=b''): - super(ContinuationFrame, self).__init__(state, length, flags, stream_id) - self.header_block_fragment = header_block_fragment - - @classmethod - def from_bytes(self, state, length, flags, stream_id, payload): - f = self(state=state, length=length, flags=flags, stream_id=stream_id) - f.header_block_fragment = payload - return f - - def payload_bytes(self): - if self.stream_id == 0x0: - raise ValueError( - 'CONTINUATION frames MUST be associated with a stream.') - - return self.header_block_fragment - - def payload_human_readable(self): - return "header_block_fragment: %s" % str(self.header_block_fragment) - -_FRAME_CLASSES = [ - DataFrame, - HeadersFrame, - PriorityFrame, - RstStreamFrame, - SettingsFrame, - PushPromiseFrame, - PingFrame, - GoAwayFrame, - WindowUpdateFrame, - ContinuationFrame -] -FRAMES = {cls.TYPE: cls for cls in _FRAME_CLASSES} 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 diff --git a/netlib/http2/frame.py b/netlib/http2/frame.py new file mode 100644 index 00000000..1497380a --- /dev/null +++ b/netlib/http2/frame.py @@ -0,0 +1,625 @@ +import struct +import logging +from functools import reduce +from hpack.hpack import Encoder, Decoder + +from .. import utils + +log = logging.getLogger(__name__) + + +class FrameSizeError(Exception): + pass + + +class Frame(object): + + """ + Baseclass Frame + contains header + payload is defined in subclasses + """ + + FLAG_NO_FLAGS = 0x0 + FLAG_ACK = 0x1 + FLAG_END_STREAM = 0x1 + FLAG_END_HEADERS = 0x4 + FLAG_PADDED = 0x8 + FLAG_PRIORITY = 0x20 + + def __init__( + self, + state=None, + length=0, + flags=FLAG_NO_FLAGS, + stream_id=0x0): + valid_flags = reduce(lambda x, y: x | y, self.VALID_FLAGS, 0x0) + if flags | valid_flags != valid_flags: + raise ValueError('invalid flags detected.') + + if state is None: + from . import HTTP2Protocol + + class State(object): + pass + + state = State() + state.http2_settings = HTTP2Protocol.HTTP2_DEFAULT_SETTINGS.copy() + state.encoder = Encoder() + state.decoder = Decoder() + + self.state = state + + self.length = length + self.type = self.TYPE + self.flags = flags + self.stream_id = stream_id + + @classmethod + def _check_frame_size(self, length, state): + from . import HTTP2Protocol + + if state: + settings = state.http2_settings + else: + settings = HTTP2Protocol.HTTP2_DEFAULT_SETTINGS + + max_frame_size = settings[ + SettingsFrame.SETTINGS.SETTINGS_MAX_FRAME_SIZE] + + if length > max_frame_size: + raise FrameSizeError( + "Frame size exceeded: %d, but only %d allowed." % ( + length, max_frame_size)) + + @classmethod + def from_file(self, fp, state=None): + """ + read a HTTP/2 frame sent by a server or client + fp is a "file like" object that could be backed by a network + stream or a disk or an in memory stream reader + """ + raw_header = fp.safe_read(9) + + fields = struct.unpack("!HBBBL", raw_header) + length = (fields[0] << 8) + fields[1] + flags = fields[3] + stream_id = fields[4] + + self._check_frame_size(length, state) + + payload = fp.safe_read(length) + return FRAMES[fields[2]].from_bytes( + state, + length, + flags, + stream_id, + payload) + + def to_bytes(self): + payload = self.payload_bytes() + self.length = len(payload) + + self._check_frame_size(self.length, self.state) + + b = struct.pack('!HB', self.length & 0xFFFF00, self.length & 0x0000FF) + b += struct.pack('!B', self.TYPE) + b += struct.pack('!B', self.flags) + b += struct.pack('!L', self.stream_id & 0x7FFFFFFF) + b += payload + + return b + + def payload_bytes(self): # pragma: no cover + raise NotImplementedError() + + def payload_human_readable(self): # pragma: no cover + raise NotImplementedError() + + def human_readable(self): + return "\n".join([ + "============================================================", + "length: %d bytes" % self.length, + "type: %s (%#x)" % (self.__class__.__name__, self.TYPE), + "flags: %#x" % self.flags, + "stream_id: %#x" % self.stream_id, + "------------------------------------------------------------", + self.payload_human_readable(), + "============================================================", + ]) + + def __eq__(self, other): + return self.to_bytes() == other.to_bytes() + + +class DataFrame(Frame): + TYPE = 0x0 + VALID_FLAGS = [Frame.FLAG_END_STREAM, Frame.FLAG_PADDED] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + payload=b'', + pad_length=0): + super(DataFrame, self).__init__(state, length, flags, stream_id) + self.payload = payload + self.pad_length = pad_length + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + + if f.flags & self.FLAG_PADDED: + f.pad_length = struct.unpack('!B', payload[0])[0] + f.payload = payload[1:-f.pad_length] + else: + f.payload = payload + + return f + + def payload_bytes(self): + if self.stream_id == 0x0: + raise ValueError('DATA frames MUST be associated with a stream.') + + b = b'' + if self.flags & self.FLAG_PADDED: + b += struct.pack('!B', self.pad_length) + + b += bytes(self.payload) + + if self.flags & self.FLAG_PADDED: + b += b'\0' * self.pad_length + + return b + + def payload_human_readable(self): + return "payload: %s" % str(self.payload) + + +class HeadersFrame(Frame): + TYPE = 0x1 + VALID_FLAGS = [ + Frame.FLAG_END_STREAM, + Frame.FLAG_END_HEADERS, + Frame.FLAG_PADDED, + Frame.FLAG_PRIORITY] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + header_block_fragment=b'', + pad_length=0, + exclusive=False, + stream_dependency=0x0, + weight=0): + super(HeadersFrame, self).__init__(state, length, flags, stream_id) + + self.header_block_fragment = header_block_fragment + self.pad_length = pad_length + self.exclusive = exclusive + self.stream_dependency = stream_dependency + self.weight = weight + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + + if f.flags & self.FLAG_PADDED: + f.pad_length = struct.unpack('!B', payload[0])[0] + f.header_block_fragment = payload[1:-f.pad_length] + else: + f.header_block_fragment = payload[0:] + + if f.flags & self.FLAG_PRIORITY: + f.stream_dependency, f.weight = struct.unpack( + '!LB', f.header_block_fragment[:5]) + f.exclusive = bool(f.stream_dependency >> 31) + f.stream_dependency &= 0x7FFFFFFF + f.header_block_fragment = f.header_block_fragment[5:] + + return f + + def payload_bytes(self): + if self.stream_id == 0x0: + raise ValueError('HEADERS frames MUST be associated with a stream.') + + b = b'' + if self.flags & self.FLAG_PADDED: + b += struct.pack('!B', self.pad_length) + + if self.flags & self.FLAG_PRIORITY: + b += struct.pack('!LB', + (int(self.exclusive) << 31) | self.stream_dependency, + self.weight) + + b += self.header_block_fragment + + if self.flags & self.FLAG_PADDED: + b += b'\0' * self.pad_length + + return b + + def payload_human_readable(self): + s = [] + + if self.flags & self.FLAG_PRIORITY: + s.append("exclusive: %d" % self.exclusive) + s.append("stream dependency: %#x" % self.stream_dependency) + s.append("weight: %d" % self.weight) + + if self.flags & self.FLAG_PADDED: + s.append("padding: %d" % self.pad_length) + + s.append( + "header_block_fragment: %s" % + self.header_block_fragment.encode('hex')) + + return "\n".join(s) + + +class PriorityFrame(Frame): + TYPE = 0x2 + VALID_FLAGS = [] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + exclusive=False, + stream_dependency=0x0, + weight=0): + super(PriorityFrame, self).__init__(state, length, flags, stream_id) + self.exclusive = exclusive + self.stream_dependency = stream_dependency + self.weight = weight + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + + f.stream_dependency, f.weight = struct.unpack('!LB', payload) + f.exclusive = bool(f.stream_dependency >> 31) + f.stream_dependency &= 0x7FFFFFFF + + return f + + def payload_bytes(self): + if self.stream_id == 0x0: + raise ValueError( + 'PRIORITY frames MUST be associated with a stream.') + + if self.stream_dependency == 0x0: + raise ValueError('stream dependency is invalid.') + + return struct.pack( + '!LB', + (int( + self.exclusive) << 31) | self.stream_dependency, + self.weight) + + def payload_human_readable(self): + s = [] + s.append("exclusive: %d" % self.exclusive) + s.append("stream dependency: %#x" % self.stream_dependency) + s.append("weight: %d" % self.weight) + return "\n".join(s) + + +class RstStreamFrame(Frame): + TYPE = 0x3 + VALID_FLAGS = [] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + error_code=0x0): + super(RstStreamFrame, self).__init__(state, length, flags, stream_id) + self.error_code = error_code + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + f.error_code = struct.unpack('!L', payload)[0] + return f + + def payload_bytes(self): + if self.stream_id == 0x0: + raise ValueError( + 'RST_STREAM frames MUST be associated with a stream.') + + return struct.pack('!L', self.error_code) + + def payload_human_readable(self): + return "error code: %#x" % self.error_code + + +class SettingsFrame(Frame): + TYPE = 0x4 + VALID_FLAGS = [Frame.FLAG_ACK] + + SETTINGS = utils.BiDi( + SETTINGS_HEADER_TABLE_SIZE=0x1, + SETTINGS_ENABLE_PUSH=0x2, + SETTINGS_MAX_CONCURRENT_STREAMS=0x3, + SETTINGS_INITIAL_WINDOW_SIZE=0x4, + SETTINGS_MAX_FRAME_SIZE=0x5, + SETTINGS_MAX_HEADER_LIST_SIZE=0x6, + ) + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + settings=None): + super(SettingsFrame, self).__init__(state, length, flags, stream_id) + + if settings is None: + settings = {} + + self.settings = settings + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + + for i in xrange(0, len(payload), 6): + identifier, value = struct.unpack("!HL", payload[i:i + 6]) + f.settings[identifier] = value + + return f + + def payload_bytes(self): + if self.stream_id != 0x0: + raise ValueError( + 'SETTINGS frames MUST NOT be associated with a stream.') + + b = b'' + for identifier, value in self.settings.items(): + b += struct.pack("!HL", identifier & 0xFF, value) + + return b + + def payload_human_readable(self): + s = [] + + for identifier, value in self.settings.items(): + s.append("%s: %#x" % (self.SETTINGS.get_name(identifier), value)) + + if not s: + return "settings: None" + else: + return "\n".join(s) + + +class PushPromiseFrame(Frame): + TYPE = 0x5 + VALID_FLAGS = [Frame.FLAG_END_HEADERS, Frame.FLAG_PADDED] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + promised_stream=0x0, + header_block_fragment=b'', + pad_length=0): + super(PushPromiseFrame, self).__init__(state, length, flags, stream_id) + self.pad_length = pad_length + self.promised_stream = promised_stream + self.header_block_fragment = header_block_fragment + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + + if f.flags & self.FLAG_PADDED: + f.pad_length, f.promised_stream = struct.unpack('!BL', payload[:5]) + f.header_block_fragment = payload[5:-f.pad_length] + else: + f.promised_stream = int(struct.unpack("!L", payload[:4])[0]) + f.header_block_fragment = payload[4:] + + f.promised_stream &= 0x7FFFFFFF + + return f + + def payload_bytes(self): + if self.stream_id == 0x0: + raise ValueError( + 'PUSH_PROMISE frames MUST be associated with a stream.') + + if self.promised_stream == 0x0: + raise ValueError('Promised stream id not valid.') + + b = b'' + if self.flags & self.FLAG_PADDED: + b += struct.pack('!B', self.pad_length) + + b += struct.pack('!L', self.promised_stream & 0x7FFFFFFF) + b += bytes(self.header_block_fragment) + + if self.flags & self.FLAG_PADDED: + b += b'\0' * self.pad_length + + return b + + def payload_human_readable(self): + s = [] + + if self.flags & self.FLAG_PADDED: + s.append("padding: %d" % self.pad_length) + + s.append("promised stream: %#x" % self.promised_stream) + s.append("header_block_fragment: %s" % str(self.header_block_fragment)) + return "\n".join(s) + + +class PingFrame(Frame): + TYPE = 0x6 + VALID_FLAGS = [Frame.FLAG_ACK] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + payload=b''): + super(PingFrame, self).__init__(state, length, flags, stream_id) + self.payload = payload + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + f.payload = payload + return f + + def payload_bytes(self): + if self.stream_id != 0x0: + raise ValueError( + 'PING frames MUST NOT be associated with a stream.') + + b = self.payload[0:8] + b += b'\0' * (8 - len(b)) + return b + + def payload_human_readable(self): + return "opaque data: %s" % str(self.payload) + + +class GoAwayFrame(Frame): + TYPE = 0x7 + VALID_FLAGS = [] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + last_stream=0x0, + error_code=0x0, + data=b''): + super(GoAwayFrame, self).__init__(state, length, flags, stream_id) + self.last_stream = last_stream + self.error_code = error_code + self.data = data + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + + f.last_stream, f.error_code = struct.unpack("!LL", payload[:8]) + f.last_stream &= 0x7FFFFFFF + f.data = payload[8:] + + return f + + def payload_bytes(self): + if self.stream_id != 0x0: + raise ValueError( + 'GOAWAY frames MUST NOT be associated with a stream.') + + b = struct.pack('!LL', self.last_stream & 0x7FFFFFFF, self.error_code) + b += bytes(self.data) + return b + + def payload_human_readable(self): + s = [] + s.append("last stream: %#x" % self.last_stream) + s.append("error code: %d" % self.error_code) + s.append("debug data: %s" % str(self.data)) + return "\n".join(s) + + +class WindowUpdateFrame(Frame): + TYPE = 0x8 + VALID_FLAGS = [] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + window_size_increment=0x0): + super(WindowUpdateFrame, self).__init__(state, length, flags, stream_id) + self.window_size_increment = window_size_increment + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + + f.window_size_increment = struct.unpack("!L", payload)[0] + f.window_size_increment &= 0x7FFFFFFF + + return f + + def payload_bytes(self): + if self.window_size_increment <= 0 or self.window_size_increment >= 2 ** 31: + raise ValueError( + 'Window Szie Increment MUST be greater than 0 and less than 2^31.') + + return struct.pack('!L', self.window_size_increment & 0x7FFFFFFF) + + def payload_human_readable(self): + return "window size increment: %#x" % self.window_size_increment + + +class ContinuationFrame(Frame): + TYPE = 0x9 + VALID_FLAGS = [Frame.FLAG_END_HEADERS] + + def __init__( + self, + state=None, + length=0, + flags=Frame.FLAG_NO_FLAGS, + stream_id=0x0, + header_block_fragment=b''): + super(ContinuationFrame, self).__init__(state, length, flags, stream_id) + self.header_block_fragment = header_block_fragment + + @classmethod + def from_bytes(self, state, length, flags, stream_id, payload): + f = self(state=state, length=length, flags=flags, stream_id=stream_id) + f.header_block_fragment = payload + return f + + def payload_bytes(self): + if self.stream_id == 0x0: + raise ValueError( + 'CONTINUATION frames MUST be associated with a stream.') + + return self.header_block_fragment + + def payload_human_readable(self): + return "header_block_fragment: %s" % str(self.header_block_fragment) + +_FRAME_CLASSES = [ + DataFrame, + HeadersFrame, + PriorityFrame, + RstStreamFrame, + SettingsFrame, + PushPromiseFrame, + PingFrame, + GoAwayFrame, + WindowUpdateFrame, + ContinuationFrame +] +FRAMES = {cls.TYPE: cls for cls in _FRAME_CLASSES} -- cgit v1.2.3