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client.py
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1531 lines (1287 loc) · 55.3 KB
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r"""HTTP/1.1 client library
<intro stuff goes here>
<other stuff, too>
HTTPConnection goes through a number of "states", which define when a client
may legally make another request or fetch the response for a particular
request. This diagram details these state transitions:
(null)
|
| HTTPConnection()
v
Idle
|
| putrequest()
v
Request-started
|
| ( putheader() )* endheaders()
v
Request-sent
|\_____________________________
| | getresponse() raises
| response = getresponse() | ConnectionError
v v
Unread-response Idle
[Response-headers-read]
|\____________________
| |
| response.read() | putrequest()
v v
Idle Req-started-unread-response
______/|
/ |
response.read() | | ( putheader() )* endheaders()
v v
Request-started Req-sent-unread-response
|
| response.read()
v
Request-sent
This diagram presents the following rules:
-- a second request may not be started until {response-headers-read}
-- a response [object] cannot be retrieved until {request-sent}
-- there is no differentiation between an unread response body and a
partially read response body
Note: this enforcement is applied by the HTTPConnection class. The
HTTPResponse class does not enforce this state machine, which
implies sophisticated clients may accelerate the request/response
pipeline. Caution should be taken, though: accelerating the states
beyond the above pattern may imply knowledge of the server's
connection-close behavior for certain requests. For example, it
is impossible to tell whether the server will close the connection
UNTIL the response headers have been read; this means that further
requests cannot be placed into the pipeline until it is known that
the server will NOT be closing the connection.
Logical State __state __response
------------- ------- ----------
Idle _CS_IDLE None
Request-started _CS_REQ_STARTED None
Request-sent _CS_REQ_SENT None
Unread-response _CS_IDLE <response_class>
Req-started-unread-response _CS_REQ_STARTED <response_class>
Req-sent-unread-response _CS_REQ_SENT <response_class>
"""
import email.parser
import email.message
import errno
import http
import io
import re
import socket
import sys
import collections.abc
from urllib.parse import urlsplit
# HTTPMessage, parse_headers(), and the HTTP status code constants are
# intentionally omitted for simplicity
__all__ = ["HTTPResponse", "HTTPConnection",
"HTTPException", "NotConnected", "UnknownProtocol",
"UnknownTransferEncoding", "UnimplementedFileMode",
"IncompleteRead", "InvalidURL", "ImproperConnectionState",
"CannotSendRequest", "CannotSendHeader", "ResponseNotReady",
"BadStatusLine", "LineTooLong", "RemoteDisconnected", "error",
"responses"]
HTTP_PORT = 80
HTTPS_PORT = 443
_UNKNOWN = 'UNKNOWN'
# connection states
_CS_IDLE = 'Idle'
_CS_REQ_STARTED = 'Request-started'
_CS_REQ_SENT = 'Request-sent'
# hack to maintain backwards compatibility
globals().update(http.HTTPStatus.__members__)
# another hack to maintain backwards compatibility
# Mapping status codes to official W3C names
responses = {v: v.phrase for v in http.HTTPStatus.__members__.values()}
# maximal line length when calling readline().
_MAXLINE = 65536
_MAXHEADERS = 100
# Header name/value ABNF (http://tools.ietf.org/html/rfc7230#section-3.2)
#
# VCHAR = %x21-7E
# obs-text = %x80-FF
# header-field = field-name ":" OWS field-value OWS
# field-name = token
# field-value = *( field-content / obs-fold )
# field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ]
# field-vchar = VCHAR / obs-text
#
# obs-fold = CRLF 1*( SP / HTAB )
# ; obsolete line folding
# ; see Section 3.2.4
# token = 1*tchar
#
# tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*"
# / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
# / DIGIT / ALPHA
# ; any VCHAR, except delimiters
#
# VCHAR defined in http://tools.ietf.org/html/rfc5234#appendix-B.1
# the patterns for both name and value are more lenient than RFC
# definitions to allow for backwards compatibility
_is_legal_header_name = re.compile(rb'[^:\s][^:\r\n]*').fullmatch
_is_illegal_header_value = re.compile(rb'\n(?![ \t])|\r(?![ \t\n])').search
# These characters are not allowed within HTTP URL paths.
# See https://tools.ietf.org/html/rfc3986#section-3.3 and the
# https://tools.ietf.org/html/rfc3986#appendix-A pchar definition.
# Prevents CVE-2019-9740. Includes control characters such as \r\n.
# We don't restrict chars above \x7f as putrequest() limits us to ASCII.
_contains_disallowed_url_pchar_re = re.compile('[\x00-\x20\x7f]')
# Arguably only these _should_ allowed:
# _is_allowed_url_pchars_re = re.compile(r"^[/!$&'()*+,;=:@%a-zA-Z0-9._~-]+$")
# We are more lenient for assumed real world compatibility purposes.
# These characters are not allowed within HTTP method names
# to prevent http header injection.
_contains_disallowed_method_pchar_re = re.compile('[\x00-\x1f]')
# We always set the Content-Length header for these methods because some
# servers will otherwise respond with a 411
_METHODS_EXPECTING_BODY = {'PATCH', 'POST', 'PUT'}
def _encode(data, name='data'):
"""Call data.encode("latin-1") but show a better error message."""
try:
return data.encode("latin-1")
except UnicodeEncodeError as err:
raise UnicodeEncodeError(
err.encoding,
err.object,
err.start,
err.end,
"%s (%.20r) is not valid Latin-1. Use %s.encode('utf-8') "
"if you want to send it encoded in UTF-8." %
(name.title(), data[err.start:err.end], name)) from None
class HTTPMessage(email.message.Message):
# XXX The only usage of this method is in
# http.server.CGIHTTPRequestHandler. Maybe move the code there so
# that it doesn't need to be part of the public API. The API has
# never been defined so this could cause backwards compatibility
# issues.
def getallmatchingheaders(self, name):
"""Find all header lines matching a given header name.
Look through the list of headers and find all lines matching a given
header name (and their continuation lines). A list of the lines is
returned, without interpretation. If the header does not occur, an
empty list is returned. If the header occurs multiple times, all
occurrences are returned. Case is not important in the header name.
"""
name = name.lower() + ':'
n = len(name)
lst = []
hit = 0
for line in self.keys():
if line[:n].lower() == name:
hit = 1
elif not line[:1].isspace():
hit = 0
if hit:
lst.append(line)
return lst
def _read_headers(fp):
"""Reads potential header lines into a list from a file pointer.
Length of line is limited by _MAXLINE, and number of
headers is limited by _MAXHEADERS.
"""
headers = []
while True:
line = fp.readline(_MAXLINE + 1)
if len(line) > _MAXLINE:
raise LineTooLong("header line")
headers.append(line)
if len(headers) > _MAXHEADERS:
raise HTTPException("got more than %d headers" % _MAXHEADERS)
if line in (b'\r\n', b'\n', b''):
break
return headers
def _parse_header_lines(header_lines, _class=HTTPMessage):
"""
Parses only RFC2822 headers from header lines.
email Parser wants to see strings rather than bytes.
But a TextIOWrapper around self.rfile would buffer too many bytes
from the stream, bytes which we later need to read as bytes.
So we read the correct bytes here, as bytes, for email Parser
to parse.
"""
hstring = b''.join(header_lines).decode('iso-8859-1')
return email.parser.Parser(_class=_class).parsestr(hstring)
def parse_headers(fp, _class=HTTPMessage):
"""Parses only RFC2822 headers from a file pointer."""
headers = _read_headers(fp)
return _parse_header_lines(headers, _class)
class HTTPResponse(io.BufferedIOBase):
# See RFC 2616 sec 19.6 and RFC 1945 sec 6 for details.
# The bytes from the socket object are iso-8859-1 strings.
# See RFC 2616 sec 2.2 which notes an exception for MIME-encoded
# text following RFC 2047. The basic status line parsing only
# accepts iso-8859-1.
def __init__(self, sock, debuglevel=0, method=None, url=None):
# If the response includes a content-length header, we need to
# make sure that the client doesn't read more than the
# specified number of bytes. If it does, it will block until
# the server times out and closes the connection. This will
# happen if a self.fp.read() is done (without a size) whether
# self.fp is buffered or not. So, no self.fp.read() by
# clients unless they know what they are doing.
self.fp = sock.makefile("rb")
self.debuglevel = debuglevel
self._method = method
# The HTTPResponse object is returned via urllib. The clients
# of http and urllib expect different attributes for the
# headers. headers is used here and supports urllib. msg is
# provided as a backwards compatibility layer for http
# clients.
self.headers = self.msg = None
# from the Status-Line of the response
self.version = _UNKNOWN # HTTP-Version
self.status = _UNKNOWN # Status-Code
self.reason = _UNKNOWN # Reason-Phrase
self.chunked = _UNKNOWN # is "chunked" being used?
self.chunk_left = _UNKNOWN # bytes left to read in current chunk
self.length = _UNKNOWN # number of bytes left in response
self.will_close = _UNKNOWN # conn will close at end of response
def _read_status(self):
line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
if len(line) > _MAXLINE:
raise LineTooLong("status line")
if self.debuglevel > 0:
print("reply:", repr(line))
if not line:
# Presumably, the server closed the connection before
# sending a valid response.
raise RemoteDisconnected("Remote end closed connection without"
" response")
try:
version, status, reason = line.split(None, 2)
except ValueError:
try:
version, status = line.split(None, 1)
reason = ""
except ValueError:
# empty version will cause next test to fail.
version = ""
if not version.startswith("HTTP/"):
self._close_conn()
raise BadStatusLine(line)
# The status code is a three-digit number
try:
status = int(status)
if status < 100 or status > 999:
raise BadStatusLine(line)
except ValueError:
raise BadStatusLine(line)
return version, status, reason
def begin(self):
if self.headers is not None:
# we've already started reading the response
return
# read until we get a non-100 response
while True:
version, status, reason = self._read_status()
if status != CONTINUE:
break
# skip the header from the 100 response
skipped_headers = _read_headers(self.fp)
if self.debuglevel > 0:
print("headers:", skipped_headers)
del skipped_headers
self.code = self.status = status
self.reason = reason.strip()
if version in ("HTTP/1.0", "HTTP/0.9"):
# Some servers might still return "0.9", treat it as 1.0 anyway
self.version = 10
elif version.startswith("HTTP/1."):
self.version = 11 # use HTTP/1.1 code for HTTP/1.x where x>=1
else:
raise UnknownProtocol(version)
self.headers = self.msg = parse_headers(self.fp)
if self.debuglevel > 0:
for hdr, val in self.headers.items():
print("header:", hdr + ":", val)
# are we using the chunked-style of transfer encoding?
tr_enc = self.headers.get("transfer-encoding")
if tr_enc and tr_enc.lower() == "chunked":
self.chunked = True
self.chunk_left = None
else:
self.chunked = False
# will the connection close at the end of the response?
self.will_close = self._check_close()
# do we have a Content-Length?
# NOTE: RFC 2616, S4.4, #3 says we ignore this if tr_enc is "chunked"
self.length = None
length = self.headers.get("content-length")
if length and not self.chunked:
try:
self.length = int(length)
except ValueError:
self.length = None
else:
if self.length < 0: # ignore nonsensical negative lengths
self.length = None
else:
self.length = None
# does the body have a fixed length? (of zero)
if (status == NO_CONTENT or status == NOT_MODIFIED or
100 <= status < 200 or # 1xx codes
self._method == "HEAD"):
self.length = 0
# if the connection remains open, and we aren't using chunked, and
# a content-length was not provided, then assume that the connection
# WILL close.
if (not self.will_close and
not self.chunked and
self.length is None):
self.will_close = True
def _check_close(self):
conn = self.headers.get("connection")
if self.version == 11:
# An HTTP/1.1 proxy is assumed to stay open unless
# explicitly closed.
if conn and "close" in conn.lower():
return True
return False
# Some HTTP/1.0 implementations have support for persistent
# connections, using rules different than HTTP/1.1.
# For older HTTP, Keep-Alive indicates persistent connection.
if self.headers.get("keep-alive"):
return False
# At least Akamai returns a "Connection: Keep-Alive" header,
# which was supposed to be sent by the client.
if conn and "keep-alive" in conn.lower():
return False
# Proxy-Connection is a netscape hack.
pconn = self.headers.get("proxy-connection")
if pconn and "keep-alive" in pconn.lower():
return False
# otherwise, assume it will close
return True
def _close_conn(self):
fp = self.fp
self.fp = None
fp.close()
def close(self):
try:
super().close() # set "closed" flag
finally:
if self.fp:
self._close_conn()
# These implementations are for the benefit of io.BufferedReader.
# XXX This class should probably be revised to act more like
# the "raw stream" that BufferedReader expects.
def flush(self):
super().flush()
if self.fp:
self.fp.flush()
def readable(self):
"""Always returns True"""
return True
# End of "raw stream" methods
def isclosed(self):
"""True if the connection is closed."""
# NOTE: it is possible that we will not ever call self.close(). This
# case occurs when will_close is TRUE, length is None, and we
# read up to the last byte, but NOT past it.
#
# IMPLIES: if will_close is FALSE, then self.close() will ALWAYS be
# called, meaning self.isclosed() is meaningful.
return self.fp is None
def read(self, amt=None):
"""Read and return the response body, or up to the next amt bytes."""
if self.fp is None:
return b""
if self._method == "HEAD":
self._close_conn()
return b""
if self.chunked:
return self._read_chunked(amt)
if amt is not None:
if self.length is not None and amt > self.length:
# clip the read to the "end of response"
amt = self.length
s = self.fp.read(amt)
if not s and amt:
# Ideally, we would raise IncompleteRead if the content-length
# wasn't satisfied, but it might break compatibility.
self._close_conn()
elif self.length is not None:
self.length -= len(s)
if not self.length:
self._close_conn()
return s
else:
# Amount is not given (unbounded read) so we must check self.length
if self.length is None:
s = self.fp.read()
else:
try:
s = self._safe_read(self.length)
except IncompleteRead:
self._close_conn()
raise
self.length = 0
self._close_conn() # we read everything
return s
def readinto(self, b):
"""Read up to len(b) bytes into bytearray b and return the number
of bytes read.
"""
if self.fp is None:
return 0
if self._method == "HEAD":
self._close_conn()
return 0
if self.chunked:
return self._readinto_chunked(b)
if self.length is not None:
if len(b) > self.length:
# clip the read to the "end of response"
b = memoryview(b)[0:self.length]
# we do not use _safe_read() here because this may be a .will_close
# connection, and the user is reading more bytes than will be provided
# (for example, reading in 1k chunks)
n = self.fp.readinto(b)
if not n and b:
# Ideally, we would raise IncompleteRead if the content-length
# wasn't satisfied, but it might break compatibility.
self._close_conn()
elif self.length is not None:
self.length -= n
if not self.length:
self._close_conn()
return n
def _read_next_chunk_size(self):
# Read the next chunk size from the file
line = self.fp.readline(_MAXLINE + 1)
if len(line) > _MAXLINE:
raise LineTooLong("chunk size")
i = line.find(b";")
if i >= 0:
line = line[:i] # strip chunk-extensions
try:
return int(line, 16)
except ValueError:
# close the connection as protocol synchronisation is
# probably lost
self._close_conn()
raise
def _read_and_discard_trailer(self):
# read and discard trailer up to the CRLF terminator
### note: we shouldn't have any trailers!
while True:
line = self.fp.readline(_MAXLINE + 1)
if len(line) > _MAXLINE:
raise LineTooLong("trailer line")
if not line:
# a vanishingly small number of sites EOF without
# sending the trailer
break
if line in (b'\r\n', b'\n', b''):
break
def _get_chunk_left(self):
# return self.chunk_left, reading a new chunk if necessary.
# chunk_left == 0: at the end of the current chunk, need to close it
# chunk_left == None: No current chunk, should read next.
# This function returns non-zero or None if the last chunk has
# been read.
chunk_left = self.chunk_left
if not chunk_left: # Can be 0 or None
if chunk_left is not None:
# We are at the end of chunk, discard chunk end
self._safe_read(2) # toss the CRLF at the end of the chunk
try:
chunk_left = self._read_next_chunk_size()
except ValueError:
raise IncompleteRead(b'')
if chunk_left == 0:
# last chunk: 1*("0") [ chunk-extension ] CRLF
self._read_and_discard_trailer()
# we read everything; close the "file"
self._close_conn()
chunk_left = None
self.chunk_left = chunk_left
return chunk_left
def _read_chunked(self, amt=None):
assert self.chunked != _UNKNOWN
value = []
try:
while (chunk_left := self._get_chunk_left()) is not None:
if amt is not None and amt <= chunk_left:
value.append(self._safe_read(amt))
self.chunk_left = chunk_left - amt
break
value.append(self._safe_read(chunk_left))
if amt is not None:
amt -= chunk_left
self.chunk_left = 0
return b''.join(value)
except IncompleteRead as exc:
raise IncompleteRead(b''.join(value)) from exc
def _readinto_chunked(self, b):
assert self.chunked != _UNKNOWN
total_bytes = 0
mvb = memoryview(b)
try:
while True:
chunk_left = self._get_chunk_left()
if chunk_left is None:
return total_bytes
if len(mvb) <= chunk_left:
n = self._safe_readinto(mvb)
self.chunk_left = chunk_left - n
return total_bytes + n
temp_mvb = mvb[:chunk_left]
n = self._safe_readinto(temp_mvb)
mvb = mvb[n:]
total_bytes += n
self.chunk_left = 0
except IncompleteRead:
raise IncompleteRead(bytes(b[0:total_bytes]))
def _safe_read(self, amt):
"""Read the number of bytes requested.
This function should be used when <amt> bytes "should" be present for
reading. If the bytes are truly not available (due to EOF), then the
IncompleteRead exception can be used to detect the problem.
"""
data = self.fp.read(amt)
if len(data) < amt:
raise IncompleteRead(data, amt-len(data))
return data
def _safe_readinto(self, b):
"""Same as _safe_read, but for reading into a buffer."""
amt = len(b)
n = self.fp.readinto(b)
if n < amt:
raise IncompleteRead(bytes(b[:n]), amt-n)
return n
def read1(self, n=-1):
"""Read with at most one underlying system call. If at least one
byte is buffered, return that instead.
"""
if self.fp is None or self._method == "HEAD":
return b""
if self.chunked:
return self._read1_chunked(n)
if self.length is not None and (n < 0 or n > self.length):
n = self.length
result = self.fp.read1(n)
if not result and n:
self._close_conn()
elif self.length is not None:
self.length -= len(result)
return result
def peek(self, n=-1):
# Having this enables IOBase.readline() to read more than one
# byte at a time
if self.fp is None or self._method == "HEAD":
return b""
if self.chunked:
return self._peek_chunked(n)
return self.fp.peek(n)
def readline(self, limit=-1):
if self.fp is None or self._method == "HEAD":
return b""
if self.chunked:
# Fallback to IOBase readline which uses peek() and read()
return super().readline(limit)
if self.length is not None and (limit < 0 or limit > self.length):
limit = self.length
result = self.fp.readline(limit)
if not result and limit:
self._close_conn()
elif self.length is not None:
self.length -= len(result)
return result
def _read1_chunked(self, n):
# Strictly speaking, _get_chunk_left() may cause more than one read,
# but that is ok, since that is to satisfy the chunked protocol.
chunk_left = self._get_chunk_left()
if chunk_left is None or n == 0:
return b''
if not (0 <= n <= chunk_left):
n = chunk_left # if n is negative or larger than chunk_left
read = self.fp.read1(n)
self.chunk_left -= len(read)
if not read:
raise IncompleteRead(b"")
return read
def _peek_chunked(self, n):
# Strictly speaking, _get_chunk_left() may cause more than one read,
# but that is ok, since that is to satisfy the chunked protocol.
try:
chunk_left = self._get_chunk_left()
except IncompleteRead:
return b'' # peek doesn't worry about protocol
if chunk_left is None:
return b'' # eof
# peek is allowed to return more than requested. Just request the
# entire chunk, and truncate what we get.
return self.fp.peek(chunk_left)[:chunk_left]
def fileno(self):
return self.fp.fileno()
def getheader(self, name, default=None):
'''Returns the value of the header matching *name*.
If there are multiple matching headers, the values are
combined into a single string separated by commas and spaces.
If no matching header is found, returns *default* or None if
the *default* is not specified.
If the headers are unknown, raises http.client.ResponseNotReady.
'''
if self.headers is None:
raise ResponseNotReady()
headers = self.headers.get_all(name) or default
if isinstance(headers, str) or not hasattr(headers, '__iter__'):
return headers
else:
return ', '.join(headers)
def getheaders(self):
"""Return list of (header, value) tuples."""
if self.headers is None:
raise ResponseNotReady()
return list(self.headers.items())
# We override IOBase.__iter__ so that it doesn't check for closed-ness
def __iter__(self):
return self
# For compatibility with old-style urllib responses.
def info(self):
'''Returns an instance of the class mimetools.Message containing
meta-information associated with the URL.
When the method is HTTP, these headers are those returned by
the server at the head of the retrieved HTML page (including
Content-Length and Content-Type).
When the method is FTP, a Content-Length header will be
present if (as is now usual) the server passed back a file
length in response to the FTP retrieval request. A
Content-Type header will be present if the MIME type can be
guessed.
When the method is local-file, returned headers will include
a Date representing the file's last-modified time, a
Content-Length giving file size, and a Content-Type
containing a guess at the file's type. See also the
description of the mimetools module.
'''
return self.headers
def geturl(self):
'''Return the real URL of the page.
In some cases, the HTTP server redirects a client to another
URL. The urlopen() function handles this transparently, but in
some cases the caller needs to know which URL the client was
redirected to. The geturl() method can be used to get at this
redirected URL.
'''
return self.url
def getcode(self):
'''Return the HTTP status code that was sent with the response,
or None if the URL is not an HTTP URL.
'''
return self.status
def _create_https_context(http_version):
# Function also used by urllib.request to be able to set the check_hostname
# attribute on a context object.
context = ssl._create_default_https_context()
# send ALPN extension to indicate HTTP/1.1 protocol
if http_version == 11:
context.set_alpn_protocols(['http/1.1'])
# enable PHA for TLS 1.3 connections if available
if context.post_handshake_auth is not None:
context.post_handshake_auth = True
return context
class HTTPConnection:
_http_vsn = 11
_http_vsn_str = 'HTTP/1.1'
response_class = HTTPResponse
default_port = HTTP_PORT
auto_open = 1
debuglevel = 0
@staticmethod
def _is_textIO(stream):
"""Test whether a file-like object is a text or a binary stream.
"""
return isinstance(stream, io.TextIOBase)
@staticmethod
def _get_content_length(body, method):
"""Get the content-length based on the body.
If the body is None, we set Content-Length: 0 for methods that expect
a body (RFC 7230, Section 3.3.2). We also set the Content-Length for
any method if the body is a str or bytes-like object and not a file.
"""
if body is None:
# do an explicit check for not None here to distinguish
# between unset and set but empty
if method.upper() in _METHODS_EXPECTING_BODY:
return 0
else:
return None
if hasattr(body, 'read'):
# file-like object.
return None
try:
# does it implement the buffer protocol (bytes, bytearray, array)?
mv = memoryview(body)
return mv.nbytes
except TypeError:
pass
if isinstance(body, str):
return len(body)
return None
def __init__(self, host, port=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
source_address=None, blocksize=8192):
self.timeout = timeout
self.source_address = source_address
self.blocksize = blocksize
self.sock = None
self._buffer = []
self.__response = None
self.__state = _CS_IDLE
self._method = None
self._tunnel_host = None
self._tunnel_port = None
self._tunnel_headers = {}
self._raw_proxy_headers = None
(self.host, self.port) = self._get_hostport(host, port)
self._validate_host(self.host)
# This is stored as an instance variable to allow unit
# tests to replace it with a suitable mockup
self._create_connection = socket.create_connection
def set_tunnel(self, host, port=None, headers=None):
"""Set up host and port for HTTP CONNECT tunnelling.
In a connection that uses HTTP CONNECT tunnelling, the host passed to
the constructor is used as a proxy server that relays all communication
to the endpoint passed to `set_tunnel`. This done by sending an HTTP
CONNECT request to the proxy server when the connection is established.
This method must be called before the HTTP connection has been
established.
The headers argument should be a mapping of extra HTTP headers to send
with the CONNECT request.
As HTTP/1.1 is used for HTTP CONNECT tunnelling request, as per the RFC
(https://tools.ietf.org/html/rfc7231#section-4.3.6), a HTTP Host:
header must be provided, matching the authority-form of the request
target provided as the destination for the CONNECT request. If a
HTTP Host: header is not provided via the headers argument, one
is generated and transmitted automatically.
"""
if self.sock:
raise RuntimeError("Can't set up tunnel for established connection")
self._tunnel_host, self._tunnel_port = self._get_hostport(host, port)
if headers:
self._tunnel_headers = headers.copy()
else:
self._tunnel_headers.clear()
if not any(header.lower() == "host" for header in self._tunnel_headers):
encoded_host = self._tunnel_host.encode("idna").decode("ascii")
self._tunnel_headers["Host"] = "%s:%d" % (
encoded_host, self._tunnel_port)
def _get_hostport(self, host, port):
if port is None:
i = host.rfind(':')
j = host.rfind(']') # ipv6 addresses have [...]
if i > j:
try:
port = int(host[i+1:])
except ValueError:
if host[i+1:] == "": # http://foo.com:/ == http://foo.com/
port = self.default_port
else:
raise InvalidURL("nonnumeric port: '%s'" % host[i+1:])
host = host[:i]
else:
port = self.default_port
if host and host[0] == '[' and host[-1] == ']':
host = host[1:-1]
return (host, port)
def set_debuglevel(self, level):
self.debuglevel = level
def _tunnel(self):
connect = b"CONNECT %s:%d %s\r\n" % (
self._tunnel_host.encode("idna"), self._tunnel_port,
self._http_vsn_str.encode("ascii"))
headers = [connect]
for header, value in self._tunnel_headers.items():
headers.append(f"{header}: {value}\r\n".encode("latin-1"))
headers.append(b"\r\n")
# Making a single send() call instead of one per line encourages
# the host OS to use a more optimal packet size instead of
# potentially emitting a series of small packets.
self.send(b"".join(headers))
del headers
response = self.response_class(self.sock, method=self._method)
try:
(version, code, message) = response._read_status()
self._raw_proxy_headers = _read_headers(response.fp)
if self.debuglevel > 0:
for header in self._raw_proxy_headers:
print('header:', header.decode())
if code != http.HTTPStatus.OK:
self.close()
raise OSError(f"Tunnel connection failed: {code} {message.strip()}")
finally:
response.close()
def get_proxy_response_headers(self):
"""
Returns a dictionary with the headers of the response
received from the proxy server to the CONNECT request
sent to set the tunnel.
If the CONNECT request was not sent, the method returns None.
"""
return (
_parse_header_lines(self._raw_proxy_headers)
if self._raw_proxy_headers is not None
else None
)
def connect(self):
"""Connect to the host and port specified in __init__."""
sys.audit("http.client.connect", self, self.host, self.port)
self.sock = self._create_connection(
(self.host,self.port), self.timeout, self.source_address)
# Might fail in OSs that don't implement TCP_NODELAY
try:
self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
except OSError as e:
if e.errno != errno.ENOPROTOOPT:
raise
if self._tunnel_host:
self._tunnel()
def close(self):
"""Close the connection to the HTTP server."""
self.__state = _CS_IDLE
try:
sock = self.sock