diff options
Diffstat (limited to 'netlib/h2')
| -rw-r--r-- | netlib/h2/frame.py | 134 | ||||
| -rw-r--r-- | netlib/h2/h2.py | 65 |
2 files changed, 190 insertions, 9 deletions
diff --git a/netlib/h2/frame.py b/netlib/h2/frame.py index a7e81f48..d4294052 100644 --- a/netlib/h2/frame.py +++ b/netlib/h2/frame.py @@ -1,4 +1,5 @@ import struct +from hpack.hpack import Encoder, Decoder from .. import utils from functools import reduce @@ -25,10 +26,28 @@ class Frame(object): raise ValueError('invalid flags detected.') self.length = length + self.type = self.TYPE self.flags = flags self.stream_id = stream_id @classmethod + def from_file(self, fp): + """ + 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] + + payload = fp.safe_read(length) + return FRAMES[fields[2]].from_bytes(length, flags, stream_id, payload) + + @classmethod def from_bytes(self, data): fields = struct.unpack("!HBBBL", data[:9]) length = (fields[0] << 8) + fields[1] @@ -49,6 +68,24 @@ class Frame(object): 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() @@ -89,15 +126,21 @@ class DataFrame(Frame): 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, length=0, flags=Frame.FLAG_NO_FLAGS, stream_id=0x0, header_block_fragment=b'', - pad_length=0, exclusive=False, stream_dependency=0x0, weight=0): + def __init__(self, length=0, flags=Frame.FLAG_NO_FLAGS, stream_id=0x0, headers=None, pad_length=0, exclusive=False, stream_dependency=0x0, weight=0): super(HeadersFrame, self).__init__(length, flags, stream_id) - self.header_block_fragment = header_block_fragment + + if headers is None: + headers = [] + + self.headers = headers self.pad_length = pad_length self.exclusive = exclusive self.stream_dependency = stream_dependency @@ -109,15 +152,18 @@ class HeadersFrame(Frame): if f.flags & self.FLAG_PADDED: f.pad_length = struct.unpack('!B', payload[0])[0] - f.header_block_fragment = payload[1:-f.pad_length] + header_block_fragment = payload[1:-f.pad_length] else: - f.header_block_fragment = payload[0:] + 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.stream_dependency, f.weight = struct.unpack('!LB', header_block_fragment[:5]) f.exclusive = bool(f.stream_dependency >> 31) f.stream_dependency &= 0x7FFFFFFF - f.header_block_fragment = f.header_block_fragment[5:] + header_block_fragment = header_block_fragment[5:] + + for header, value in Decoder().decode(header_block_fragment): + f.headers.append((header, value)) return f @@ -132,13 +178,32 @@ class HeadersFrame(Frame): if self.flags & self.FLAG_PRIORITY: b += struct.pack('!LB', (int(self.exclusive) << 31) | self.stream_dependency, self.weight) - b += bytes(self.header_block_fragment) + b += Encoder().encode(self.headers) 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) + + if not self.headers: + s.append("headers: None") + else: + for header, value in self.headers: + s.append("%s: %s" % (header, value)) + + return "\n".join(s) + class PriorityFrame(Frame): TYPE = 0x2 @@ -169,6 +234,13 @@ class PriorityFrame(Frame): 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 @@ -190,6 +262,9 @@ class RstStreamFrame(Frame): return struct.pack('!L', self.error_code) + def payload_human_readable(self): + return "error code: %#x" % self.error_code + class SettingsFrame(Frame): TYPE = 0x4 @@ -204,8 +279,12 @@ class SettingsFrame(Frame): SETTINGS_MAX_HEADER_LIST_SIZE=0x6, ) - def __init__(self, length=0, flags=Frame.FLAG_NO_FLAGS, stream_id=0x0, settings={}): + def __init__(self, length=0, flags=Frame.FLAG_NO_FLAGS, stream_id=0x0, settings=None): super(SettingsFrame, self).__init__(length, flags, stream_id) + + if settings is None: + settings = {} + self.settings = settings @classmethod @@ -228,6 +307,17 @@ class SettingsFrame(Frame): 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 @@ -273,6 +363,16 @@ class PushPromiseFrame(Frame): 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 @@ -296,6 +396,9 @@ class PingFrame(Frame): 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 @@ -325,6 +428,13 @@ class GoAwayFrame(Frame): 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 @@ -349,6 +459,9 @@ class WindowUpdateFrame(Frame): 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 @@ -370,6 +483,9 @@ class ContinuationFrame(Frame): return self.header_block_fragment + def payload_human_readable(self): + return "header_block_fragment: %s" % str(self.header_block_fragment) + _FRAME_CLASSES = [ DataFrame, HeadersFrame, diff --git a/netlib/h2/h2.py b/netlib/h2/h2.py index 7a85226f..bfe5832b 100644 --- a/netlib/h2/h2.py +++ b/netlib/h2/h2.py @@ -1,3 +1,5 @@ +from .. import utils, odict, tcp +from frame import * # "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n" CLIENT_CONNECTION_PREFACE = '505249202a20485454502f322e300d0a0d0a534d0d0a0d0a' @@ -18,3 +20,66 @@ ERROR_CODES = utils.BiDi( INADEQUATE_SECURITY=0xc, HTTP_1_1_REQUIRED=0xd ) + + +class H2Client(tcp.TCPClient): + ALPN_PROTO_H2 = b'h2' + + 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, address, source_address=None): + super(H2Client, self).__init__(address, source_address) + self.settings = self.DEFAULT_SETTINGS.copy() + + def connect(self, send_preface=True): + super(H2Client, self).connect() + self.convert_to_ssl(alpn_protos=[self.ALPN_PROTO_H2]) + + alp = self.get_alpn_proto_negotiated() + if alp != b'h2': + raise NotImplementedError("H2Client can not handle unknown protocol: %s" % alp) + print "-> Successfully negotiated 'h2' application layer protocol." + + if send_preface: + self.wfile.write(bytes(CLIENT_CONNECTION_PREFACE.decode('hex'))) + self.send_frame(SettingsFrame()) + + frame = Frame.from_file(self.rfile) + print frame.human_readable() + assert isinstance(frame, SettingsFrame) + self.apply_settings(frame.settings) + + print "-> Connection Preface completed." + + print "-> H2Client is ready..." + + def send_frame(self, frame): + self.wfile.write(frame.to_bytes()) + self.wfile.flush() + + def read_frame(self): + frame = Frame.from_file(self.rfile) + 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.settings[setting] + if not old_value: + old_value = '-' + + self.settings[setting] = value + print "-> Setting changed: %s to %d (was %s)" % + (SettingsFrame.SETTINGS.get_name(setting), value, str(old_value)) + + self.send_frame(SettingsFrame(flags=Frame.FLAG_ACK)) + print "-> New settings acknowledged." |