Use persistent connections

1 files changed, 391 insertions, 0 deletions

diff --git a/python/urllib3/connection.py b/python/urllib3/connection.py
new file mode 100644
index 0000000..02b3665
--- /dev/null
+++ b/python/urllib3/connection.py
@@ -0,0 +1,391 @@
+from __future__ import absolute_import
+import datetime
+import logging
+import os
+import socket
+from socket import error as SocketError, timeout as SocketTimeout
+import warnings
+from .packages import six
+from .packages.six.moves.http_client import HTTPConnection as _HTTPConnection
+from .packages.six.moves.http_client import HTTPException  # noqa: F401
+
+try:  # Compiled with SSL?
+    import ssl
+    BaseSSLError = ssl.SSLError
+except (ImportError, AttributeError):  # Platform-specific: No SSL.
+    ssl = None
+
+    class BaseSSLError(BaseException):
+        pass
+
+
+try:  # Python 3:
+    # Not a no-op, we're adding this to the namespace so it can be imported.
+    ConnectionError = ConnectionError
+except NameError:  # Python 2:
+    class ConnectionError(Exception):
+        pass
+
+
+from .exceptions import (
+    NewConnectionError,
+    ConnectTimeoutError,
+    SubjectAltNameWarning,
+    SystemTimeWarning,
+)
+from .packages.ssl_match_hostname import match_hostname, CertificateError
+
+from .util.ssl_ import (
+    resolve_cert_reqs,
+    resolve_ssl_version,
+    assert_fingerprint,
+    create_urllib3_context,
+    ssl_wrap_socket
+)
+
+
+from .util import connection
+
+from ._collections import HTTPHeaderDict
+
+log = logging.getLogger(__name__)
+
+port_by_scheme = {
+    'http': 80,
+    'https': 443,
+}
+
+# When updating RECENT_DATE, move it to within two years of the current date,
+# and not less than 6 months ago.
+# Example: if Today is 2018-01-01, then RECENT_DATE should be any date on or
+# after 2016-01-01 (today - 2 years) AND before 2017-07-01 (today - 6 months)
+RECENT_DATE = datetime.date(2017, 6, 30)
+
+
+class DummyConnection(object):
+    """Used to detect a failed ConnectionCls import."""
+    pass
+
+
+class HTTPConnection(_HTTPConnection, object):
+    """
+    Based on httplib.HTTPConnection but provides an extra constructor
+    backwards-compatibility layer between older and newer Pythons.
+
+    Additional keyword parameters are used to configure attributes of the connection.
+    Accepted parameters include:
+
+      - ``strict``: See the documentation on :class:`urllib3.connectionpool.HTTPConnectionPool`
+      - ``source_address``: Set the source address for the current connection.
+      - ``socket_options``: Set specific options on the underlying socket. If not specified, then
+        defaults are loaded from ``HTTPConnection.default_socket_options`` which includes disabling
+        Nagle's algorithm (sets TCP_NODELAY to 1) unless the connection is behind a proxy.
+
+        For example, if you wish to enable TCP Keep Alive in addition to the defaults,
+        you might pass::
+
+            HTTPConnection.default_socket_options + [
+                (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1),
+            ]
+
+        Or you may want to disable the defaults by passing an empty list (e.g., ``[]``).
+    """
+
+    default_port = port_by_scheme['http']
+
+    #: Disable Nagle's algorithm by default.
+    #: ``[(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]``
+    default_socket_options = [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]
+
+    #: Whether this connection verifies the host's certificate.
+    is_verified = False
+
+    def __init__(self, *args, **kw):
+        if six.PY3:  # Python 3
+            kw.pop('strict', None)
+
+        # Pre-set source_address.
+        self.source_address = kw.get('source_address')
+
+        #: The socket options provided by the user. If no options are
+        #: provided, we use the default options.
+        self.socket_options = kw.pop('socket_options', self.default_socket_options)
+
+        _HTTPConnection.__init__(self, *args, **kw)
+
+    @property
+    def host(self):
+        """
+        Getter method to remove any trailing dots that indicate the hostname is an FQDN.
+
+        In general, SSL certificates don't include the trailing dot indicating a
+        fully-qualified domain name, and thus, they don't validate properly when
+        checked against a domain name that includes the dot. In addition, some
+        servers may not expect to receive the trailing dot when provided.
+
+        However, the hostname with trailing dot is critical to DNS resolution; doing a
+        lookup with the trailing dot will properly only resolve the appropriate FQDN,
+        whereas a lookup without a trailing dot will search the system's search domain
+        list. Thus, it's important to keep the original host around for use only in
+        those cases where it's appropriate (i.e., when doing DNS lookup to establish the
+        actual TCP connection across which we're going to send HTTP requests).
+        """
+        return self._dns_host.rstrip('.')
+
+    @host.setter
+    def host(self, value):
+        """
+        Setter for the `host` property.
+
+        We assume that only urllib3 uses the _dns_host attribute; httplib itself
+        only uses `host`, and it seems reasonable that other libraries follow suit.
+        """
+        self._dns_host = value
+
+    def _new_conn(self):
+        """ Establish a socket connection and set nodelay settings on it.
+
+        :return: New socket connection.
+        """
+        extra_kw = {}
+        if self.source_address:
+            extra_kw['source_address'] = self.source_address
+
+        if self.socket_options:
+            extra_kw['socket_options'] = self.socket_options
+
+        try:
+            conn = connection.create_connection(
+                (self._dns_host, self.port), self.timeout, **extra_kw)
+
+        except SocketTimeout as e:
+            raise ConnectTimeoutError(
+                self, "Connection to %s timed out. (connect timeout=%s)" %
+                (self.host, self.timeout))
+
+        except SocketError as e:
+            raise NewConnectionError(
+                self, "Failed to establish a new connection: %s" % e)
+
+        return conn
+
+    def _prepare_conn(self, conn):
+        self.sock = conn
+        if self._tunnel_host:
+            # TODO: Fix tunnel so it doesn't depend on self.sock state.
+            self._tunnel()
+            # Mark this connection as not reusable
+            self.auto_open = 0
+
+    def connect(self):
+        conn = self._new_conn()
+        self._prepare_conn(conn)
+
+    def request_chunked(self, method, url, body=None, headers=None):
+        """
+        Alternative to the common request method, which sends the
+        body with chunked encoding and not as one block
+        """
+        headers = HTTPHeaderDict(headers if headers is not None else {})
+        skip_accept_encoding = 'accept-encoding' in headers
+        skip_host = 'host' in headers
+        self.putrequest(
+            method,
+            url,
+            skip_accept_encoding=skip_accept_encoding,
+            skip_host=skip_host
+        )
+        for header, value in headers.items():
+            self.putheader(header, value)
+        if 'transfer-encoding' not in headers:
+            self.putheader('Transfer-Encoding', 'chunked')
+        self.endheaders()
+
+        if body is not None:
+            stringish_types = six.string_types + (bytes,)
+            if isinstance(body, stringish_types):
+                body = (body,)
+            for chunk in body:
+                if not chunk:
+                    continue
+                if not isinstance(chunk, bytes):
+                    chunk = chunk.encode('utf8')
+                len_str = hex(len(chunk))[2:]
+                self.send(len_str.encode('utf-8'))
+                self.send(b'\r\n')
+                self.send(chunk)
+                self.send(b'\r\n')
+
+        # After the if clause, to always have a closed body
+        self.send(b'0\r\n\r\n')
+
+
+class HTTPSConnection(HTTPConnection):
+    default_port = port_by_scheme['https']
+
+    ssl_version = None
+
+    def __init__(self, host, port=None, key_file=None, cert_file=None,
+                 strict=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+                 ssl_context=None, server_hostname=None, **kw):
+
+        HTTPConnection.__init__(self, host, port, strict=strict,
+                                timeout=timeout, **kw)
+
+        self.key_file = key_file
+        self.cert_file = cert_file
+        self.ssl_context = ssl_context
+        self.server_hostname = server_hostname
+
+        # Required property for Google AppEngine 1.9.0 which otherwise causes
+        # HTTPS requests to go out as HTTP. (See Issue #356)
+        self._protocol = 'https'
+
+    def connect(self):
+        conn = self._new_conn()
+        self._prepare_conn(conn)
+
+        if self.ssl_context is None:
+            self.ssl_context = create_urllib3_context(
+                ssl_version=resolve_ssl_version(None),
+                cert_reqs=resolve_cert_reqs(None),
+            )
+
+        self.sock = ssl_wrap_socket(
+            sock=conn,
+            keyfile=self.key_file,
+            certfile=self.cert_file,
+            ssl_context=self.ssl_context,
+            server_hostname=self.server_hostname
+        )
+
+
+class VerifiedHTTPSConnection(HTTPSConnection):
+    """
+    Based on httplib.HTTPSConnection but wraps the socket with
+    SSL certification.
+    """
+    cert_reqs = None
+    ca_certs = None
+    ca_cert_dir = None
+    ssl_version = None
+    assert_fingerprint = None
+
+    def set_cert(self, key_file=None, cert_file=None,
+                 cert_reqs=None, ca_certs=None,
+                 assert_hostname=None, assert_fingerprint=None,
+                 ca_cert_dir=None):
+        """
+        This method should only be called once, before the connection is used.
+        """
+        # If cert_reqs is not provided, we can try to guess. If the user gave
+        # us a cert database, we assume they want to use it: otherwise, if
+        # they gave us an SSL Context object we should use whatever is set for
+        # it.
+        if cert_reqs is None:
+            if ca_certs or ca_cert_dir:
+                cert_reqs = 'CERT_REQUIRED'
+            elif self.ssl_context is not None:
+                cert_reqs = self.ssl_context.verify_mode
+
+        self.key_file = key_file
+        self.cert_file = cert_file
+        self.cert_reqs = cert_reqs
+        self.assert_hostname = assert_hostname
+        self.assert_fingerprint = assert_fingerprint
+        self.ca_certs = ca_certs and os.path.expanduser(ca_certs)
+        self.ca_cert_dir = ca_cert_dir and os.path.expanduser(ca_cert_dir)
+
+    def connect(self):
+        # Add certificate verification
+        conn = self._new_conn()
+        hostname = self.host
+
+        if self._tunnel_host:
+            self.sock = conn
+            # Calls self._set_hostport(), so self.host is
+            # self._tunnel_host below.
+            self._tunnel()
+            # Mark this connection as not reusable
+            self.auto_open = 0
+
+            # Override the host with the one we're requesting data from.
+            hostname = self._tunnel_host
+
+        server_hostname = hostname
+        if self.server_hostname is not None:
+            server_hostname = self.server_hostname
+
+        is_time_off = datetime.date.today() < RECENT_DATE
+        if is_time_off:
+            warnings.warn((
+                'System time is way off (before {0}). This will probably '
+                'lead to SSL verification errors').format(RECENT_DATE),
+                SystemTimeWarning
+            )
+
+        # Wrap socket using verification with the root certs in
+        # trusted_root_certs
+        if self.ssl_context is None:
+            self.ssl_context = create_urllib3_context(
+                ssl_version=resolve_ssl_version(self.ssl_version),
+                cert_reqs=resolve_cert_reqs(self.cert_reqs),
+            )
+
+        context = self.ssl_context
+        context.verify_mode = resolve_cert_reqs(self.cert_reqs)
+        self.sock = ssl_wrap_socket(
+            sock=conn,
+            keyfile=self.key_file,
+            certfile=self.cert_file,
+            ca_certs=self.ca_certs,
+            ca_cert_dir=self.ca_cert_dir,
+            server_hostname=server_hostname,
+            ssl_context=context)
+
+        if self.assert_fingerprint:
+            assert_fingerprint(self.sock.getpeercert(binary_form=True),
+                               self.assert_fingerprint)
+        elif context.verify_mode != ssl.CERT_NONE \
+                and not getattr(context, 'check_hostname', False) \
+                and self.assert_hostname is not False:
+            # While urllib3 attempts to always turn off hostname matching from
+            # the TLS library, this cannot always be done. So we check whether
+            # the TLS Library still thinks it's matching hostnames.
+            cert = self.sock.getpeercert()
+            if not cert.get('subjectAltName', ()):
+                warnings.warn((
+                    'Certificate for {0} has no `subjectAltName`, falling back to check for a '
+                    '`commonName` for now. This feature is being removed by major browsers and '
+                    'deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 '
+                    'for details.)'.format(hostname)),
+                    SubjectAltNameWarning
+                )
+            _match_hostname(cert, self.assert_hostname or server_hostname)
+
+        self.is_verified = (
+            context.verify_mode == ssl.CERT_REQUIRED or
+            self.assert_fingerprint is not None
+        )
+
+
+def _match_hostname(cert, asserted_hostname):
+    try:
+        match_hostname(cert, asserted_hostname)
+    except CertificateError as e:
+        log.error(
+            'Certificate did not match expected hostname: %s. '
+            'Certificate: %s', asserted_hostname, cert
+        )
+        # Add cert to exception and reraise so client code can inspect
+        # the cert when catching the exception, if they want to
+        e._peer_cert = cert
+        raise
+
+
+if ssl:
+    # Make a copy for testing.
+    UnverifiedHTTPSConnection = HTTPSConnection
+    HTTPSConnection = VerifiedHTTPSConnection
+else:
+    HTTPSConnection = DummyConnection