%PDF-
%PDF-
Mini Shell
Mini Shell
import abc
import asyncio
import collections
import re
import string
import zlib
from enum import IntEnum
from typing import Any, List, Optional, Tuple, Type, Union
from multidict import CIMultiDict, CIMultiDictProxy, istr
from yarl import URL
from . import hdrs
from .base_protocol import BaseProtocol
from .helpers import NO_EXTENSIONS, BaseTimerContext
from .http_exceptions import (
BadStatusLine,
ContentEncodingError,
ContentLengthError,
InvalidHeader,
LineTooLong,
TransferEncodingError,
)
from .http_writer import HttpVersion, HttpVersion10
from .log import internal_logger
from .streams import EMPTY_PAYLOAD, StreamReader
from .typedefs import RawHeaders
try:
import brotli
HAS_BROTLI = True
except ImportError: # pragma: no cover
HAS_BROTLI = False
__all__ = (
"HeadersParser",
"HttpParser",
"HttpRequestParser",
"HttpResponseParser",
"RawRequestMessage",
"RawResponseMessage",
)
ASCIISET = set(string.printable)
# See https://tools.ietf.org/html/rfc7230#section-3.1.1
# and https://tools.ietf.org/html/rfc7230#appendix-B
#
# method = token
# tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" / "." /
# "^" / "_" / "`" / "|" / "~" / DIGIT / ALPHA
# token = 1*tchar
METHRE = re.compile(r"[!#$%&'*+\-.^_`|~0-9A-Za-z]+")
VERSRE = re.compile(r"HTTP/(\d+).(\d+)")
HDRRE = re.compile(rb"[\x00-\x1F\x7F()<>@,;:\[\]={} \t\\\\\"]")
RawRequestMessage = collections.namedtuple(
"RawRequestMessage",
[
"method",
"path",
"version",
"headers",
"raw_headers",
"should_close",
"compression",
"upgrade",
"chunked",
"url",
],
)
RawResponseMessage = collections.namedtuple(
"RawResponseMessage",
[
"version",
"code",
"reason",
"headers",
"raw_headers",
"should_close",
"compression",
"upgrade",
"chunked",
],
)
class ParseState(IntEnum):
PARSE_NONE = 0
PARSE_LENGTH = 1
PARSE_CHUNKED = 2
PARSE_UNTIL_EOF = 3
class ChunkState(IntEnum):
PARSE_CHUNKED_SIZE = 0
PARSE_CHUNKED_CHUNK = 1
PARSE_CHUNKED_CHUNK_EOF = 2
PARSE_MAYBE_TRAILERS = 3
PARSE_TRAILERS = 4
class HeadersParser:
def __init__(
self,
max_line_size: int = 8190,
max_headers: int = 32768,
max_field_size: int = 8190,
) -> None:
self.max_line_size = max_line_size
self.max_headers = max_headers
self.max_field_size = max_field_size
def parse_headers(
self, lines: List[bytes]
) -> Tuple["CIMultiDictProxy[str]", RawHeaders]:
headers = CIMultiDict() # type: CIMultiDict[str]
raw_headers = []
lines_idx = 1
line = lines[1]
line_count = len(lines)
while line:
# Parse initial header name : value pair.
try:
bname, bvalue = line.split(b":", 1)
except ValueError:
raise InvalidHeader(line) from None
bname = bname.strip(b" \t")
bvalue = bvalue.lstrip()
if HDRRE.search(bname):
raise InvalidHeader(bname)
if len(bname) > self.max_field_size:
raise LineTooLong(
"request header name {}".format(
bname.decode("utf8", "xmlcharrefreplace")
),
str(self.max_field_size),
str(len(bname)),
)
header_length = len(bvalue)
# next line
lines_idx += 1
line = lines[lines_idx]
# consume continuation lines
continuation = line and line[0] in (32, 9) # (' ', '\t')
if continuation:
bvalue_lst = [bvalue]
while continuation:
header_length += len(line)
if header_length > self.max_field_size:
raise LineTooLong(
"request header field {}".format(
bname.decode("utf8", "xmlcharrefreplace")
),
str(self.max_field_size),
str(header_length),
)
bvalue_lst.append(line)
# next line
lines_idx += 1
if lines_idx < line_count:
line = lines[lines_idx]
if line:
continuation = line[0] in (32, 9) # (' ', '\t')
else:
line = b""
break
bvalue = b"".join(bvalue_lst)
else:
if header_length > self.max_field_size:
raise LineTooLong(
"request header field {}".format(
bname.decode("utf8", "xmlcharrefreplace")
),
str(self.max_field_size),
str(header_length),
)
bvalue = bvalue.strip()
name = bname.decode("utf-8", "surrogateescape")
value = bvalue.decode("utf-8", "surrogateescape")
headers.add(name, value)
raw_headers.append((bname, bvalue))
return (CIMultiDictProxy(headers), tuple(raw_headers))
class HttpParser(abc.ABC):
def __init__(
self,
protocol: Optional[BaseProtocol] = None,
loop: Optional[asyncio.AbstractEventLoop] = None,
limit: int = 2 ** 16,
max_line_size: int = 8190,
max_headers: int = 32768,
max_field_size: int = 8190,
timer: Optional[BaseTimerContext] = None,
code: Optional[int] = None,
method: Optional[str] = None,
readall: bool = False,
payload_exception: Optional[Type[BaseException]] = None,
response_with_body: bool = True,
read_until_eof: bool = False,
auto_decompress: bool = True,
) -> None:
self.protocol = protocol
self.loop = loop
self.max_line_size = max_line_size
self.max_headers = max_headers
self.max_field_size = max_field_size
self.timer = timer
self.code = code
self.method = method
self.readall = readall
self.payload_exception = payload_exception
self.response_with_body = response_with_body
self.read_until_eof = read_until_eof
self._lines = [] # type: List[bytes]
self._tail = b""
self._upgraded = False
self._payload = None
self._payload_parser = None # type: Optional[HttpPayloadParser]
self._auto_decompress = auto_decompress
self._limit = limit
self._headers_parser = HeadersParser(max_line_size, max_headers, max_field_size)
@abc.abstractmethod
def parse_message(self, lines: List[bytes]) -> Any:
pass
def feed_eof(self) -> Any:
if self._payload_parser is not None:
self._payload_parser.feed_eof()
self._payload_parser = None
else:
# try to extract partial message
if self._tail:
self._lines.append(self._tail)
if self._lines:
if self._lines[-1] != "\r\n":
self._lines.append(b"")
try:
return self.parse_message(self._lines)
except Exception:
return None
def feed_data(
self,
data: bytes,
SEP: bytes = b"\r\n",
EMPTY: bytes = b"",
CONTENT_LENGTH: istr = hdrs.CONTENT_LENGTH,
METH_CONNECT: str = hdrs.METH_CONNECT,
SEC_WEBSOCKET_KEY1: istr = hdrs.SEC_WEBSOCKET_KEY1,
) -> Tuple[List[Any], bool, bytes]:
messages = []
if self._tail:
data, self._tail = self._tail + data, b""
data_len = len(data)
start_pos = 0
loop = self.loop
while start_pos < data_len:
# read HTTP message (request/response line + headers), \r\n\r\n
# and split by lines
if self._payload_parser is None and not self._upgraded:
pos = data.find(SEP, start_pos)
# consume \r\n
if pos == start_pos and not self._lines:
start_pos = pos + 2
continue
if pos >= start_pos:
# line found
self._lines.append(data[start_pos:pos])
start_pos = pos + 2
# \r\n\r\n found
if self._lines[-1] == EMPTY:
try:
msg = self.parse_message(self._lines)
finally:
self._lines.clear()
# payload length
length = msg.headers.get(CONTENT_LENGTH)
if length is not None:
try:
length = int(length)
except ValueError:
raise InvalidHeader(CONTENT_LENGTH)
if length < 0:
raise InvalidHeader(CONTENT_LENGTH)
# do not support old websocket spec
if SEC_WEBSOCKET_KEY1 in msg.headers:
raise InvalidHeader(SEC_WEBSOCKET_KEY1)
self._upgraded = msg.upgrade
method = getattr(msg, "method", self.method)
assert self.protocol is not None
# calculate payload
if (
(length is not None and length > 0)
or msg.chunked
and not msg.upgrade
):
payload = StreamReader(
self.protocol,
timer=self.timer,
loop=loop,
limit=self._limit,
)
payload_parser = HttpPayloadParser(
payload,
length=length,
chunked=msg.chunked,
method=method,
compression=msg.compression,
code=self.code,
readall=self.readall,
response_with_body=self.response_with_body,
auto_decompress=self._auto_decompress,
)
if not payload_parser.done:
self._payload_parser = payload_parser
elif method == METH_CONNECT:
payload = StreamReader(
self.protocol,
timer=self.timer,
loop=loop,
limit=self._limit,
)
self._upgraded = True
self._payload_parser = HttpPayloadParser(
payload,
method=msg.method,
compression=msg.compression,
readall=True,
auto_decompress=self._auto_decompress,
)
else:
if (
getattr(msg, "code", 100) >= 199
and length is None
and self.read_until_eof
):
payload = StreamReader(
self.protocol,
timer=self.timer,
loop=loop,
limit=self._limit,
)
payload_parser = HttpPayloadParser(
payload,
length=length,
chunked=msg.chunked,
method=method,
compression=msg.compression,
code=self.code,
readall=True,
response_with_body=self.response_with_body,
auto_decompress=self._auto_decompress,
)
if not payload_parser.done:
self._payload_parser = payload_parser
else:
payload = EMPTY_PAYLOAD # type: ignore
messages.append((msg, payload))
else:
self._tail = data[start_pos:]
data = EMPTY
break
# no parser, just store
elif self._payload_parser is None and self._upgraded:
assert not self._lines
break
# feed payload
elif data and start_pos < data_len:
assert not self._lines
assert self._payload_parser is not None
try:
eof, data = self._payload_parser.feed_data(data[start_pos:])
except BaseException as exc:
if self.payload_exception is not None:
self._payload_parser.payload.set_exception(
self.payload_exception(str(exc))
)
else:
self._payload_parser.payload.set_exception(exc)
eof = True
data = b""
if eof:
start_pos = 0
data_len = len(data)
self._payload_parser = None
continue
else:
break
if data and start_pos < data_len:
data = data[start_pos:]
else:
data = EMPTY
return messages, self._upgraded, data
def parse_headers(
self, lines: List[bytes]
) -> Tuple[
"CIMultiDictProxy[str]", RawHeaders, Optional[bool], Optional[str], bool, bool
]:
"""Parses RFC 5322 headers from a stream.
Line continuations are supported. Returns list of header name
and value pairs. Header name is in upper case.
"""
headers, raw_headers = self._headers_parser.parse_headers(lines)
close_conn = None
encoding = None
upgrade = False
chunked = False
# keep-alive
conn = headers.get(hdrs.CONNECTION)
if conn:
v = conn.lower()
if v == "close":
close_conn = True
elif v == "keep-alive":
close_conn = False
elif v == "upgrade":
upgrade = True
# encoding
enc = headers.get(hdrs.CONTENT_ENCODING)
if enc:
enc = enc.lower()
if enc in ("gzip", "deflate", "br"):
encoding = enc
# chunking
te = headers.get(hdrs.TRANSFER_ENCODING)
if te and "chunked" in te.lower():
chunked = True
return (headers, raw_headers, close_conn, encoding, upgrade, chunked)
def set_upgraded(self, val: bool) -> None:
"""Set connection upgraded (to websocket) mode.
:param bool val: new state.
"""
self._upgraded = val
class HttpRequestParser(HttpParser):
"""Read request status line. Exception .http_exceptions.BadStatusLine
could be raised in case of any errors in status line.
Returns RawRequestMessage.
"""
def parse_message(self, lines: List[bytes]) -> Any:
# request line
line = lines[0].decode("utf-8", "surrogateescape")
try:
method, path, version = line.split(None, 2)
except ValueError:
raise BadStatusLine(line) from None
if len(path) > self.max_line_size:
raise LineTooLong(
"Status line is too long", str(self.max_line_size), str(len(path))
)
path_part, _hash_separator, url_fragment = path.partition("#")
path_part, _question_mark_separator, qs_part = path_part.partition("?")
# method
if not METHRE.match(method):
raise BadStatusLine(method)
# version
try:
if version.startswith("HTTP/"):
n1, n2 = version[5:].split(".", 1)
version_o = HttpVersion(int(n1), int(n2))
else:
raise BadStatusLine(version)
except Exception:
raise BadStatusLine(version)
# read headers
(
headers,
raw_headers,
close,
compression,
upgrade,
chunked,
) = self.parse_headers(lines)
if close is None: # then the headers weren't set in the request
if version_o <= HttpVersion10: # HTTP 1.0 must asks to not close
close = True
else: # HTTP 1.1 must ask to close.
close = False
return RawRequestMessage(
method,
path,
version_o,
headers,
raw_headers,
close,
compression,
upgrade,
chunked,
# NOTE: `yarl.URL.build()` is used to mimic what the Cython-based
# NOTE: parser does, otherwise it results into the same
# NOTE: HTTP Request-Line input producing different
# NOTE: `yarl.URL()` objects
URL.build(
path=path_part,
query_string=qs_part,
fragment=url_fragment,
encoded=True,
),
)
class HttpResponseParser(HttpParser):
"""Read response status line and headers.
BadStatusLine could be raised in case of any errors in status line.
Returns RawResponseMessage"""
def parse_message(self, lines: List[bytes]) -> Any:
line = lines[0].decode("utf-8", "surrogateescape")
try:
version, status = line.split(None, 1)
except ValueError:
raise BadStatusLine(line) from None
try:
status, reason = status.split(None, 1)
except ValueError:
reason = ""
if len(reason) > self.max_line_size:
raise LineTooLong(
"Status line is too long", str(self.max_line_size), str(len(reason))
)
# version
match = VERSRE.match(version)
if match is None:
raise BadStatusLine(line)
version_o = HttpVersion(int(match.group(1)), int(match.group(2)))
# The status code is a three-digit number
try:
status_i = int(status)
except ValueError:
raise BadStatusLine(line) from None
if status_i > 999:
raise BadStatusLine(line)
# read headers
(
headers,
raw_headers,
close,
compression,
upgrade,
chunked,
) = self.parse_headers(lines)
if close is None:
close = version_o <= HttpVersion10
return RawResponseMessage(
version_o,
status_i,
reason.strip(),
headers,
raw_headers,
close,
compression,
upgrade,
chunked,
)
class HttpPayloadParser:
def __init__(
self,
payload: StreamReader,
length: Optional[int] = None,
chunked: bool = False,
compression: Optional[str] = None,
code: Optional[int] = None,
method: Optional[str] = None,
readall: bool = False,
response_with_body: bool = True,
auto_decompress: bool = True,
) -> None:
self._length = 0
self._type = ParseState.PARSE_NONE
self._chunk = ChunkState.PARSE_CHUNKED_SIZE
self._chunk_size = 0
self._chunk_tail = b""
self._auto_decompress = auto_decompress
self.done = False
# payload decompression wrapper
if response_with_body and compression and self._auto_decompress:
real_payload = DeflateBuffer(
payload, compression
) # type: Union[StreamReader, DeflateBuffer]
else:
real_payload = payload
# payload parser
if not response_with_body:
# don't parse payload if it's not expected to be received
self._type = ParseState.PARSE_NONE
real_payload.feed_eof()
self.done = True
elif chunked:
self._type = ParseState.PARSE_CHUNKED
elif length is not None:
self._type = ParseState.PARSE_LENGTH
self._length = length
if self._length == 0:
real_payload.feed_eof()
self.done = True
else:
if readall and code != 204:
self._type = ParseState.PARSE_UNTIL_EOF
elif method in ("PUT", "POST"):
internal_logger.warning( # pragma: no cover
"Content-Length or Transfer-Encoding header is required"
)
self._type = ParseState.PARSE_NONE
real_payload.feed_eof()
self.done = True
self.payload = real_payload
def feed_eof(self) -> None:
if self._type == ParseState.PARSE_UNTIL_EOF:
self.payload.feed_eof()
elif self._type == ParseState.PARSE_LENGTH:
raise ContentLengthError(
"Not enough data for satisfy content length header."
)
elif self._type == ParseState.PARSE_CHUNKED:
raise TransferEncodingError(
"Not enough data for satisfy transfer length header."
)
def feed_data(
self, chunk: bytes, SEP: bytes = b"\r\n", CHUNK_EXT: bytes = b";"
) -> Tuple[bool, bytes]:
# Read specified amount of bytes
if self._type == ParseState.PARSE_LENGTH:
required = self._length
chunk_len = len(chunk)
if required >= chunk_len:
self._length = required - chunk_len
self.payload.feed_data(chunk, chunk_len)
if self._length == 0:
self.payload.feed_eof()
return True, b""
else:
self._length = 0
self.payload.feed_data(chunk[:required], required)
self.payload.feed_eof()
return True, chunk[required:]
# Chunked transfer encoding parser
elif self._type == ParseState.PARSE_CHUNKED:
if self._chunk_tail:
chunk = self._chunk_tail + chunk
self._chunk_tail = b""
while chunk:
# read next chunk size
if self._chunk == ChunkState.PARSE_CHUNKED_SIZE:
pos = chunk.find(SEP)
if pos >= 0:
i = chunk.find(CHUNK_EXT, 0, pos)
if i >= 0:
size_b = chunk[:i] # strip chunk-extensions
else:
size_b = chunk[:pos]
try:
size = int(bytes(size_b), 16)
except ValueError:
exc = TransferEncodingError(
chunk[:pos].decode("ascii", "surrogateescape")
)
self.payload.set_exception(exc)
raise exc from None
chunk = chunk[pos + 2 :]
if size == 0: # eof marker
self._chunk = ChunkState.PARSE_MAYBE_TRAILERS
else:
self._chunk = ChunkState.PARSE_CHUNKED_CHUNK
self._chunk_size = size
self.payload.begin_http_chunk_receiving()
else:
self._chunk_tail = chunk
return False, b""
# read chunk and feed buffer
if self._chunk == ChunkState.PARSE_CHUNKED_CHUNK:
required = self._chunk_size
chunk_len = len(chunk)
if required > chunk_len:
self._chunk_size = required - chunk_len
self.payload.feed_data(chunk, chunk_len)
return False, b""
else:
self._chunk_size = 0
self.payload.feed_data(chunk[:required], required)
chunk = chunk[required:]
self._chunk = ChunkState.PARSE_CHUNKED_CHUNK_EOF
self.payload.end_http_chunk_receiving()
# toss the CRLF at the end of the chunk
if self._chunk == ChunkState.PARSE_CHUNKED_CHUNK_EOF:
if chunk[:2] == SEP:
chunk = chunk[2:]
self._chunk = ChunkState.PARSE_CHUNKED_SIZE
else:
self._chunk_tail = chunk
return False, b""
# if stream does not contain trailer, after 0\r\n
# we should get another \r\n otherwise
# trailers needs to be skiped until \r\n\r\n
if self._chunk == ChunkState.PARSE_MAYBE_TRAILERS:
head = chunk[:2]
if head == SEP:
# end of stream
self.payload.feed_eof()
return True, chunk[2:]
# Both CR and LF, or only LF may not be received yet. It is
# expected that CRLF or LF will be shown at the very first
# byte next time, otherwise trailers should come. The last
# CRLF which marks the end of response might not be
# contained in the same TCP segment which delivered the
# size indicator.
if not head:
return False, b""
if head == SEP[:1]:
self._chunk_tail = head
return False, b""
self._chunk = ChunkState.PARSE_TRAILERS
# read and discard trailer up to the CRLF terminator
if self._chunk == ChunkState.PARSE_TRAILERS:
pos = chunk.find(SEP)
if pos >= 0:
chunk = chunk[pos + 2 :]
self._chunk = ChunkState.PARSE_MAYBE_TRAILERS
else:
self._chunk_tail = chunk
return False, b""
# Read all bytes until eof
elif self._type == ParseState.PARSE_UNTIL_EOF:
self.payload.feed_data(chunk, len(chunk))
return False, b""
class DeflateBuffer:
"""DeflateStream decompress stream and feed data into specified stream."""
def __init__(self, out: StreamReader, encoding: Optional[str]) -> None:
self.out = out
self.size = 0
self.encoding = encoding
self._started_decoding = False
if encoding == "br":
if not HAS_BROTLI: # pragma: no cover
raise ContentEncodingError(
"Can not decode content-encoding: brotli (br). "
"Please install `brotlipy`"
)
self.decompressor = brotli.Decompressor()
else:
zlib_mode = 16 + zlib.MAX_WBITS if encoding == "gzip" else zlib.MAX_WBITS
self.decompressor = zlib.decompressobj(wbits=zlib_mode)
def set_exception(self, exc: BaseException) -> None:
self.out.set_exception(exc)
def feed_data(self, chunk: bytes, size: int) -> None:
if not size:
return
self.size += size
# RFC1950
# bits 0..3 = CM = 0b1000 = 8 = "deflate"
# bits 4..7 = CINFO = 1..7 = windows size.
if (
not self._started_decoding
and self.encoding == "deflate"
and chunk[0] & 0xF != 8
):
# Change the decoder to decompress incorrectly compressed data
# Actually we should issue a warning about non-RFC-compliant data.
self.decompressor = zlib.decompressobj(wbits=-zlib.MAX_WBITS)
try:
chunk = self.decompressor.decompress(chunk)
except Exception:
raise ContentEncodingError(
"Can not decode content-encoding: %s" % self.encoding
)
self._started_decoding = True
if chunk:
self.out.feed_data(chunk, len(chunk))
def feed_eof(self) -> None:
chunk = self.decompressor.flush()
if chunk or self.size > 0:
self.out.feed_data(chunk, len(chunk))
if self.encoding == "deflate" and not self.decompressor.eof:
raise ContentEncodingError("deflate")
self.out.feed_eof()
def begin_http_chunk_receiving(self) -> None:
self.out.begin_http_chunk_receiving()
def end_http_chunk_receiving(self) -> None:
self.out.end_http_chunk_receiving()
HttpRequestParserPy = HttpRequestParser
HttpResponseParserPy = HttpResponseParser
RawRequestMessagePy = RawRequestMessage
RawResponseMessagePy = RawResponseMessage
try:
if not NO_EXTENSIONS:
from ._http_parser import ( # type: ignore
HttpRequestParser,
HttpResponseParser,
RawRequestMessage,
RawResponseMessage,
)
HttpRequestParserC = HttpRequestParser
HttpResponseParserC = HttpResponseParser
RawRequestMessageC = RawRequestMessage
RawResponseMessageC = RawResponseMessage
except ImportError: # pragma: no cover
pass
Zerion Mini Shell 1.0