gerrit.onap Code Review - sdc/sdc-distribution-client.git/blob

   1 # -*- coding: utf-8 -*-
   2 """
   3 SOCKS support for urllib3
   4 ~~~~~~~~~~~~~~~~~~~~~~~~~
   5
   6 This contrib module contains provisional support for SOCKS proxies from within
   7 urllib3. This module supports SOCKS4 (specifically the SOCKS4A variant) and
   8 SOCKS5. To enable its functionality, either install PySocks or install this
   9 module with the ``socks`` extra.
  10
  11 Known Limitations:
  12
  13 - Currently PySocks does not support contacting remote websites via literal
  14   IPv6 addresses. Any such connection attempt will fail.
  15 - Currently PySocks does not support IPv6 connections to the SOCKS proxy. Any
  16   such connection attempt will fail.
  17 """
  18 from __future__ import absolute_import
  19
  20 try:
  21     import socks
  22 except ImportError:
  23     import warnings
  24     from ..exceptions import DependencyWarning
  25
  26     warnings.warn((
  27         'SOCKS support in urllib3 requires the installation of optional '
  28         'dependencies: specifically, PySocks.  For more information, see '
  29         'https://urllib3.readthedocs.org/en/latest/contrib.html#socks-proxies'
  30         ),
  31         DependencyWarning
  32     )
  33     raise
  34
  35 from socket import error as SocketError, timeout as SocketTimeout
  36
  37 from ..connection import (
  38     HTTPConnection, HTTPSConnection
  39 )
  40 from ..connectionpool import (
  41     HTTPConnectionPool, HTTPSConnectionPool
  42 )
  43 from ..exceptions import ConnectTimeoutError, NewConnectionError
  44 from ..poolmanager import PoolManager
  45 from ..util.url import parse_url
  46
  47 try:
  48     import ssl
  49 except ImportError:
  50     ssl = None
  51
  52
  53 class SOCKSConnection(HTTPConnection):
  54     """
  55     A plain-text HTTP connection that connects via a SOCKS proxy.
  56     """
  57     def __init__(self, *args, **kwargs):
  58         self._socks_options = kwargs.pop('_socks_options')
  59         super(SOCKSConnection, self).__init__(*args, **kwargs)
  60
  61     def _new_conn(self):
  62         """
  63         Establish a new connection via the SOCKS proxy.
  64         """
  65         extra_kw = {}
  66         if self.source_address:
  67             extra_kw['source_address'] = self.source_address
  68
  69         if self.socket_options:
  70             extra_kw['socket_options'] = self.socket_options
  71
  72         try:
  73             conn = socks.create_connection(
  74                 (self.host, self.port),
  75                 proxy_type=self._socks_options['socks_version'],
  76                 proxy_addr=self._socks_options['proxy_host'],
  77                 proxy_port=self._socks_options['proxy_port'],
  78                 proxy_username=self._socks_options['username'],
  79                 proxy_password=self._socks_options['password'],
  80                 timeout=self.timeout,
  81                 **extra_kw
  82             )
  83
  84         except SocketTimeout as e:
  85             raise ConnectTimeoutError(
  86                 self, "Connection to %s timed out. (connect timeout=%s)" %
  87                 (self.host, self.timeout))
  88
  89         except socks.ProxyError as e:
  90             # This is fragile as hell, but it seems to be the only way to raise
  91             # useful errors here.
  92             if e.socket_err:
  93                 error = e.socket_err
  94                 if isinstance(error, SocketTimeout):
  95                     raise ConnectTimeoutError(
  96                         self,
  97                         "Connection to %s timed out. (connect timeout=%s)" %
  98                         (self.host, self.timeout)
  99                     )
 100                 else:
 101                     raise NewConnectionError(
 102                         self,
 103                         "Failed to establish a new connection: %s" % error
 104                     )
 105             else:
 106                 raise NewConnectionError(
 107                     self,
 108                     "Failed to establish a new connection: %s" % e
 109                 )
 110
 111         except SocketError as e:  # Defensive: PySocks should catch all these.
 112             raise NewConnectionError(
 113                 self, "Failed to establish a new connection: %s" % e)
 114
 115         return conn
 116
 117
 118 # We don't need to duplicate the Verified/Unverified distinction from
 119 # urllib3/connection.py here because the HTTPSConnection will already have been
 120 # correctly set to either the Verified or Unverified form by that module. This
 121 # means the SOCKSHTTPSConnection will automatically be the correct type.
 122 class SOCKSHTTPSConnection(SOCKSConnection, HTTPSConnection):
 123     pass
 124
 125
 126 class SOCKSHTTPConnectionPool(HTTPConnectionPool):
 127     ConnectionCls = SOCKSConnection
 128
 129
 130 class SOCKSHTTPSConnectionPool(HTTPSConnectionPool):
 131     ConnectionCls = SOCKSHTTPSConnection
 132
 133
 134 class SOCKSProxyManager(PoolManager):
 135     """
 136     A version of the urllib3 ProxyManager that routes connections via the
 137     defined SOCKS proxy.
 138     """
 139     pool_classes_by_scheme = {
 140         'http': SOCKSHTTPConnectionPool,
 141         'https': SOCKSHTTPSConnectionPool,
 142     }
 143
 144     def __init__(self, proxy_url, username=None, password=None,
 145                  num_pools=10, headers=None, **connection_pool_kw):
 146         parsed = parse_url(proxy_url)
 147
 148         if parsed.scheme == 'socks5':
 149             socks_version = socks.PROXY_TYPE_SOCKS5
 150         elif parsed.scheme == 'socks4':
 151             socks_version = socks.PROXY_TYPE_SOCKS4
 152         else:
 153             raise ValueError(
 154                 "Unable to determine SOCKS version from %s" % proxy_url
 155             )
 156
 157         self.proxy_url = proxy_url
 158
 159         socks_options = {
 160             'socks_version': socks_version,
 161             'proxy_host': parsed.host,
 162             'proxy_port': parsed.port,
 163             'username': username,
 164             'password': password,
 165         }
 166         connection_pool_kw['_socks_options'] = socks_options
 167
 168         super(SOCKSProxyManager, self).__init__(
 169             num_pools, headers, **connection_pool_kw
 170         )
 171
 172         self.pool_classes_by_scheme = SOCKSProxyManager.pool_classes_by_scheme